# Why the heck did they design it that way?



## michael rauls (Jul 17, 2018)

I would verry much like to hear everyones thoughts on design on issues pertaining to a particular plane that kept ok planes from being good, good planes from being great, and great planes from being darn near perfect( or at least as close to it as could be humanly expected at the time of its design). The obvious picks for me are two great planes that could have been darn near perfect , the Bf109 and the spitfire, both for the same two issues. Those being the narrow undercarriage and limited fuel capacity. I'm sure there are many examples so " why the heck did they design it that way"

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## pbehn (Jul 17, 2018)

michael rauls said:


> I would verry much like to hear everyones thoughts on design on issues pertaining to a particular plane that kept ok planes from being good, good planes from being great, and great planes from being darn near perfect( or at least as close to it as could be humanly expected at the time of its design). The obvious picks for me are two great planes that could have been darn near perfect , the Bf109 and the spitfire, both for the same two issues. Those being the narrow undercarriage and limited fuel capacity. I'm sure there are many examples so " why the heck did they design it that way"


The Spitfire was an interceptor, speed and rate of climb were paramount, also very important was the take off run with 1000HP and a fixed pitched prop (about 660HP in practice, on take off). In order to get a thin wing for speed with all the "stuff" in it Mitchell used an elliptical wing, with the narrow track wheels folding out. The whole thing was about getting a lightweight design to take off climb and the fly as fast as possible. The Spitfire was designed with a thin wing for low drag, later advances in aerofoils actually produced less drag from thicker wings so inward folding gear wasn't so much of a problem. The Bf 109 had a similar philosophy, its landing gear was attached close to he engine which saved a lot of weight, also allowed wings to be changed just with the plane on its landing gear. In 1936 when the Spitfire was being designed there wasn't actually a war being fought. The plane was designed and the first order placed for 300 aircraft, other allied designs that came after the war started had different requirements but as far as an interceptor goes, range isn't important.

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## Shortround6 (Jul 17, 2018)

Opinions differ 
Mine is that was what you were going to get given the* power plants available* at the time of design (several years earlier than going into service and even longer going into combat).

The 109 was designed around the Jumo 210 engine of roughly 700hp. It didn't even make 300mph as it was (and I believe the Jumo powered machines only held 270 liters of fuel?) so trying to turn it into a fuel truck would not have had good results. They built hundreds of Jumo powered 109 B, C & Ds before building DB 601 powered 109Es which got stuck with the physical size of the 109. It then started on the trying to stuff a quart into a pint jar path. 

The Spitfire and Hurricane had a better basic engine but ran into two problems as to power plant. 1. was that the Merlin III had the highest critical altitude (FTH) of any production engine (in large numbers) in the 1930s but that meant they had to throttle it down at sea level for take 0ff to 880 hp. Then the Air ministry attached shackles, leg irons and cannon balls to them in regards to take-off by insisting on two blade fixed pitch props. Take off was done at just over 2000rpm on the engine instead of the 3000rpm the engine was capable of (and where the 880hp was). 

Both countries had requirements about take-off runs and distance to 50 ft (or 20 meters for the 109) and given the engine/propeller combinations there was only so much weight the designer was going to get off the runway in the distance desired. Doesn't matter how long ranged the fighter plane is if it can't use the majority of airfields in the country (which got a lot more numerous and larger both before the war and during the early years of the war.)

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## michael rauls (Jul 17, 2018)

pbehn said:


> The Spitfire was an interceptor, speed and rate of climb were paramount, also very important was the take off run with 1000HP and a fixed pitched prop (about 660HP in practice, on take off). In order to get a thin wing for speed with all the "stuff" in it Mitchell used an elliptical wing, with the narrow track wheels folding out. The whole thing was about getting a lightweight design to take off climb and the fly as fast as possible. The Spitfire was designed with a thin wing for low drag, later advances in aerofoils actually produced less drag from thicker wings so inward folding gear wasn't so much of a problem. The Bf 109 had a similar philosophy, its landing gear was attached close to he engine which saved a lot of weight, also allowed wings to be changed just with the plane on its landing gear. In 1936 when the Spitfire was being designed there wasn't actually a war being fought. The plane was designed and the first order placed for 300 aircraft, other allied designs that came after the war started had different requirements but as far as an interceptor goes, range isn't important.


 I had considered some of the things you point out. Although many I was unaware of runway length takeoff requirements for example. But as it pertains to the Bf 109 specificly seems like the germans forsaw the posible meed for longer range fighters( hence the 110) and doesn't seem like it would add much wieght and impact performance much to increase fuel capacity 10 or 15%. If I have my numbers and math right( always a big if) a 10% increase in fuel capacity would be about 90 lbs for the 109. Especially once somewhat more powerful engines were in the plane doesn't seem like 90 lbs would impact performance much and think what a 10 or 15 % increase in flight time would have meant to the Luftwaffe durring the battle of Britain for example.


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## GrauGeist (Jul 17, 2018)

The Bf109's landing gear was an innovation of Messerschmitt's, which allowed a savings in weight by the landing gear mount and engine mounts to share a unified assembly. It also made the aircraft easy to service or transport. While the landing gear geometry made it difficult for pilots, especially on hard/improved surfaces, it was not the narrowest of landing gears - this distinction should go to Grumman's F4F.

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## michael rauls (Jul 17, 2018)

GrauGeist said:


> The Bf109's landing gear was an innovation of Messerschmitt's, which allowed a savings in weight by the landing gear mount and engine mounts to share a unified assembly. It also made the aircraft easy to service or transport. While the landing gear geometry made it difficult for pilots, especially on hard/improved surfaces, it was not the narrowest of landing gears - this distinction should go to Grumman's F4F.


 The landing gear thing makes alot more sense to me now but what do you think about a 10 or 15% increase in fuel capacity for the 109? About 90 lbs I think and like i was saying in my last post think what that would have meant to the Luftwaffe to have 10 or 15% more flight time during the Battle of Britain for example.


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## michael rauls (Jul 17, 2018)

Or what 10 or 15 % more fuel for the spitfire would have meant to the British durring Dunkirk.


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## pbehn (Jul 17, 2018)

michael rauls said:


> I had considered some of the things you point out. Although many I was unaware of runway length takeoff requirements for example. But as it pertains to the Bf 109 specificly seems like the germans forsaw the posible meed for longer range fighters( hence the 110) and doesn't seem like it would add much wieght and impact performance much to increase fuel capacity 10 or 15%. If I have my numbers and math right( always a big if) a 10% increase in fuel capacity would be about 90 lbs for the 109. Especially once somewhat more powerful engines were in the plane doesn't seem like 90 lbs would impact performance much and think what a 10 or 15 % increase in flight time would have meant to the Luftwaffe durring the battle of Britain for example.


It is perhaps difficult to understand looking back at things, planes like the P-51 had huge range eventually but early in the war it wasn't very important. In the Battle of France the LW was getting to its limit at Dunkerque operating from Germany, the further your front line is away the fewer missions you can do in a day and the harder it is to communicate what is needed where. In the Battle of Britain the LW started to attach long rage tanks, but at the time they were being attached some in the LW thought the RAF were down to their last 50 aircraft. After the BoB, you could say the RAF needed longer range fighters, but they had to be much longer, there weren't many important targets in France that the Germans were compelled to defend, though Leigh Mallory could have done a much better job.

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## pbehn (Jul 17, 2018)

michael rauls said:


> Or what 10 or 15 % more fuel for the spitfire would have meant to the British durring Dunkirk.


Well Dunkerque was a success (of sorts) as it was, 10-15% more range may have been a help, but that was the first time the Spitfire was committed in numbers. At Dunkerque a major problem was actually seeing the enemy through low cloud and smoke, more fuel wouldn't solve that. Also pilots in action were as likely to turn back due to low ammunition as much as fuel.


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## michael rauls (Jul 17, 2018)

pbehn said:


> It is perhaps difficult to understand looking back at things, planes like the P-51 had huge range eventually but early in the war it wasn't very important. In the Battle of France the LW was getting to its limit at Dunkerque operating from Germany, the further your front line is away the fewer missions you can do in a day and the harder it is to communicate what is needed where. In the Battle of Britain the LW started to attach long rage tanks, but at the time they were being attached some in the LW thought the RAF were down to their last 50 aircraft. After the BoB, you could say the RAF needed longer range fighters, but they had to be much longer, there weren't many important targets in France that the Germans were compelled to defend, though Leigh Mallory could have done a much better job.


 Verry good job explaining the why of these decisions. Thank you. I suppose whether they the best ones is a different and also interesting topic.


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## buffnut453 (Jul 17, 2018)

michael rauls said:


> Verry good job explaining the why of these decisions. Thank you. I suppose whether they the best ones is a different and also interesting topic.



They were probably the best decisions that could be made at the time, with the information available at hand AND within the constraints placed upon the designers and manufacturers. We've had countless threads on this forum about "could the Scruggs Wondaplane have been introduced 12 months earlier" and they always revert to the view that, if such acceleration of deliver were possible at the time, then it probably would have been done.

It's easy for people sitting comfortably in their armchairs in 2018 to be critical of decisions made in (insert year prior to 2018 here) but we have the benefits of hindsight that the people making decisions at the time did not possess.

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## pbehn (Jul 17, 2018)

michael rauls said:


> Verry good job explaining the why of these decisions. Thank you. I suppose whether they the best ones is a different and also interesting topic.


I forgot to say, the LWs role was mainly as a close support tactical force, not only was the LW at its limit in range at Dunkerque, the German army too was in need of rest re supply and consolidation. At D-Day the Allies had the planes with the range to fly across the Channel to Normandy, but within days of the landings, engineers were constructing mesh air strips for planes to operate from France, it is easier doing close support when you are close.


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## michael rauls (Jul 17, 2018)

pbehn said:


> Well Dunkerque was a success (of sorts) as it was, 10-15% more range may have been a help, but that was the first time the Spitfire was committed in numbers. At Dunkerque a major problem was actually seeing the enemy through low cloud and smoke, more fuel wouldn't solve that. Also pilots in action were as likely to turn back due to low ammunition as much as fuel.


 I know your write about Dunkirk being a success given the circumstances. I was trying to give an example of where even a small increase in range could have helped(maybe alot) its my understanding that the Spitfire had verry limited time over the crucial area. Seems even another 10 or 15 minutes could have saved lives. Maybe quite a few but perhaps the didn't foresee the need.


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## michael rauls (Jul 17, 2018)

buffnut453 said:


> They were probably the best decisions that could be made at the time, with the information available at hand AND within the constraints placed upon the designers and manufacturers. We've had countless threads on this forum about "could the Scruggs Wondaplane have been introduced 12 months earlier" and they always revert to the view that, if such acceleration of deliver were possible at the time, then it probably would have been done.
> 
> It's easy for people sitting comfortably in their armchairs in 2018 to be critical of decisions made in (insert year prior to 2018 here) but we have the benefits of hindsight that the people making decisions at the time did not possess.


 All your points are verry good but my idea for this thread was not an acussitory pointing of fingers at Willy Meschershmit for example but more of an honest asking of the question" why the heck did they make it that way" and an hopefully interesting discussion of such as well as the of course inevitable was it the rite decision discussion. Also usually interesting.


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## pbehn (Jul 17, 2018)

michael rauls said:


> I know your write about Dunkirk being a success given the circumstances. I was trying to give an example of where even a small increase in range could have helped(maybe alot) its my understanding that the Spitfire had verry limited time over the crucial area. Seems even another 10 or 15 minutes could have saved lives. Maybe quite a few but perhaps the didn't foresee the need.


It was not foreseen in any strategic planning that France would be in danger of falling to Germany in weeks, let alone a huge British force being encircled at Dunkerque. Dunkerque gets all the headlines, it was a sort of miracle, in most circumstances it should have been a disaster, however it is often forgotten that over 200,000 troops and civilians were returned to UK from other ports on the west coast in a more orderly and less dramatic fashion. (Operation Ariel)

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## pbehn (Jul 17, 2018)

michael rauls said:


> All your points are verry good but my idea for this thread was not an acussitory pointing of fingers at Willy Meschershmit for example but more of an honest asking of the question" why the heck did they make it that way" and an hopefully interesting discussion of such as well as the of course inevitable was it the rite decision discussion. Also usually interesting.


One decision on the Hawker Hurricane and later Typhoon that was wrong, because it was based on incorrect advice/thinking was the thickness of the wings. It was thought that thick wings were better, this turned out to be completely wrong and a major disadvantage on the Typhoon, which required new wings as the Tempest Oh and a new engine and better fuselage, the canopy was changed too lol

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## Shortround6 (Jul 17, 2018)

It is a bit more than failing to see the need. Peace time airworthiness standards were different than war time.
Adding fuel sounds easy but was often rather difficult.The fuel tank behind the pilot in the P-36/P-40 being a prime example.

In early US service with the P-36 this tank was an overload ferry tank. Used for moving the aircraft form one airfield to another. performance trials were done with the tank empty and restrictions were placed on the plane as far as allowable maneuvers when the tank was full. The French crashed at least one Hawk 75 and maybe more by ignoring that restriction.
Early P-40s also used it as an overload/ferry tank and performance numbers were obtained with the tank empty. I don't know if restrictions were placed on the early P-40s as far as flying with the tank full. When you get to the P-40E and F something a little strange happens. It is not spelled out as a restriction but in the P-40E the sequence the tanks were used was the forward wing tank first for take-off, then the belly tank if carried, then the behind the seat tank, then the rear wing tank (under the pilot) and then and finally back to the forward wing tank. On the P-40F the difference was that the rear tank (behind pilot) was to be drawn down to 35 gallons _and then that fuel was to be left there while the fuel in the other tanks was used. _Instead of the fuel in the forward wing tank being the reserve, get home, bad weather safety fuel like the E on the F the forward fuel was used sooner and the 35 gallons behind the pilot became the reserve.
I am guessing but it might have to do with the Merlin engine being several hundred pounds heavier than the Allison and they were using the 35 gallons (210lbs) as ballast to keep the CG where they wanted it. Not sure what happened when they made the fuselage 20in longer 
Sometimes adding fuel is easy and sometimes it makes the plane somewhat squirrly in handling. Some planes tended to tighten up a turn on their own once in a turn, not really a good trait. Post war both Mustangs and Spitfires with rear tanks wound up with restrictions on allowable conditions for filling/use of the rear tanks. With the need for combat gone accident prevention became a priority once again.
Ask the private pilot members about one of the major causes of single aircraft crashes, fuel management and the selection of the proper tank/s at the proper time. The more tanks/positions on the fuel selector valve the more problems per 1000 or 10,000 hours of flight.

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## michael rauls (Jul 17, 2018)

pbehn said:


> It was not foreseen in any strategic planning that France would be in danger of falling to Germany in weeks, let alone a huge British force being encircled at Dunkerque. Dunkerque gets all the headlines, it was a sort of miracle, in most circumstances it should have been a disaster, however it is often forgotten that over 200,000 troops and civilians were returned to UK from other ports on the west coast in a more orderly and less dramatic fashion. (Operation Ariel)


 Verry enlightening answers to things I have wondered about. I'm sure there are many more examples like this like leaving the supercharger off the p39 or p40 but I want to leave at least a few picks for others.


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## pbehn (Jul 17, 2018)

michael rauls said:


> Verry enlightening answers to things I have wondered about. I'm sure there are many more examples like this like leaving the supercharger off the p39 or p40 but I want to leave at least a few picks for others.


It is easy to look at the P-51s range and think "why didn't they all do that" however if by a miracle of time travel you took a P51 airframe back to 1940 but with a 1940 Merlin and fixed pitch two blade prop......the first thing they would do would be to remove two of the guns and half fill the fuel tanks.

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## michael rauls (Jul 17, 2018)

pbehn said:


> One decision on the Hawker Hurricane and later Typhoon that was wrong, because it was based on incorrect advice/thinking was the thickness of the wings. It was thought that thick wings were better, this turned out to be completely wrong and a major disadvantage on the Typhoon, which required new wings as the Tempest Oh and a new engine and better fuselage, the canopy was changed too lol


 


Shortround6 said:


> It is a bit more than failing to see the need. Peace time airworthiness standards were different than war time.
> Adding fuel sounds easy but was often rather difficult.The fuel tank behind the pilot in the P-36/P-40 being a prime example.
> 
> In early US service with the P-36 this tank was an overload ferry tank. Used for moving the aircraft form one airfield to another. performance trials were done with the tank empty and restrictions were placed on the plane as far as allowable maneuvers when the tank was full. The French crashed at least one Hawk 75 and maybe more by ignoring that restriction.
> ...


 I've read that even during the war the British had restrictions on filling and use of the rear tank on the Mustang. Is there any truth to this as far as you know.


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## pbehn (Jul 17, 2018)

michael rauls said:


> I've read that even during the war the British had restrictions on filling and use of the rear tank on the Mustang. Is there any truth to this as far as you know.


All allied forces did. The P51 with a full rear tank is not a combat plane, you need to be sure that you wont be in combat just after take off with that full.

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## michael rauls (Jul 17, 2018)

pbehn said:


> All allied forces did. The P51 with a full rear tank is not a combat plane, you need to be sure that you wont be in combat just after take off with that full.


 This might sound like a dumb question( imagine that from me) but was there any way to dump that fuel should the need arise say Luftwaffe fighters met over the English channel on the way out for example.


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## pbehn (Jul 17, 2018)

michael rauls said:


> This might sound like a dumb question( imagine that from me) but was there any way to dump that fuel should the need arise say Luftwaffe fighters met over the English channel on the way out for example.


Not that I know of, but I think most of it would have been used by the time they had warmed up, taken off, formed up and climbed. LW fighters coming over the channel would be the job of the RAF they had interceptors lol

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## GrauGeist (Jul 17, 2018)

michael rauls said:


> This might sound like a dumb question( imagine that from me) but was there any way to dump that fuel should the need arise say Luftwaffe fighters met over the English channel on the way out for example.


The rear tank was used from startup through climbing to altitude - even if the P-51 had to scramble due to incoming enemy, that was used to get the ship up.

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## michael rauls (Jul 17, 2018)

pbehn said:


> Not that I know of, but I think most of it would have been used by the time they had warmed up, taken off, formed up and climbed. LW fighters coming over the channel would be the job of the RAF they had interceptors lol


 I didn't realize that rear tank would have been used up that quickly. I guess that kinda eliminates the need to get rid of ot in a posible unexpected situation. Really appreciate you taking the time to answer these questions. I have about a thousand more but don't want to abuse the privilege as they say. So I'll save some of those for later and hopefully others will have some interesting insights into why things were designed in a way that may look at first glance at least, like an oversight. Thanks again!


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## pbehn (Jul 17, 2018)

michael rauls said:


> I didn't realize that rear tank would have been used up that quickly. I guess that kinda eliminates the need to get rid of ot in a posible unexpected situation. Really appreciate you taking the time to answer these questions. I have about a thousand more but don't want to abuse the privilege as they say. So I'll save some of those for later and hopefully others will have some interesting insights into why things were designed in a way that may look at first glance at least, like an oversight. Thanks again!


Try using the forum search function, it throws up some useful stuff.


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## michael rauls (Jul 17, 2018)

GrauGeist said:


> The rear tank was used from startup through climbing to altitude - even if the P-51 had to scramble due to incoming enemy, that was used to get the ship up.


 I didn't see your post till now. Guess you already answered my next question. Thanks!

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## pbehn (Jul 17, 2018)

michael rauls said:


> I didn't see your post till now. Guess you already answered my next question. Thanks!


The max fuel consumption of a Merlin is about 150gals/hr.


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## michael rauls (Jul 17, 2018)

pbehn said:


> Try using the forum search function, it throws up some useful stuff.


 Thanks for heads up on that. I'll give it a try.


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## wuzak (Jul 17, 2018)

michael rauls said:


> If I have my numbers and math right( always a big if) a 10% increase in fuel capacity would be about 90 lbs for the 109. Especially once somewhat more powerful engines were in the plane doesn't seem like 90 lbs would impact performance much and think what a 10 or 15 % increase in flight time would have meant to the Luftwaffe durring the battle of Britain for example.



In hindsight we know that the Spitfire and Bf 109 got more powerful engines as they were developed. But during the design and development period they really could not rely on more power being available in the short term.


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## michael rauls (Jul 17, 2018)

wuzak said:


> In hindsight we know that the Spitfire and Bf 109 got more powerful engines as they were developed. But during the design and development period they really could not rely on more power being available in the short term.


 I was thinking more along the lines of a modification to a slightly larger tank when more powerful engines became available but perhaps this was impractical.


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## michael rauls (Jul 17, 2018)

michael rauls said:


> I was thinking more along the lines of a modification to a slightly larger tank when more powerful engines became available but perhaps this was impractical.


 I guess that wouldn't be a case of original design but of later modification now that I think of it.


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## GrauGeist (Jul 17, 2018)

michael rauls said:


> I was thinking more along the lines of a modification to a slightly larger tank when more powerful engines became available but perhaps this was impractical.


More powerful engines are usually heavier than their predecessor, adding that and a larger fuel tank is imposing a weight penalty.

And keep in mind that the existing fuel tank is already engineered for the available space in the fuselage - there may not be any room for a larger tank.


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## wuzak (Jul 17, 2018)

michael rauls said:


> I was thinking more along the lines of a modification to a slightly larger tank when more powerful engines became available but perhaps this was impractical.



Supermarine did try and stuff more fuel into the Spitfire over the years.

But the amount they could add was limited by the space available in the airframe. 

They added bladder tanks in the inner leading edge of the wings of the VIII and XIV. 17.5 proper gallons each, IIRC.

Rear fuselage tanks were added, with flight restrictions due to loss of stability when they were full.

But these required modifications to the wing, which may have been factory only mods (ie produced that way) that could not be added in the field.

The forward upper tank in the XIV was bigger than the Merlin Spitfires had. Had to move things around, such as the oil tank, to fit that.

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## michael rauls (Jul 17, 2018)

GrauGeist said:


> More powerful engines are usually heavier than their predecessor, adding that and a larger fuel tank is imposing a weight penalty.
> 
> And keep in mind that the existing fuel tank is already engineered for the available space in the fuselage - there may not be any room for a larger tank.


 All good points. I was thinking that even a tiny increase in wieght of fuel could have huge benefits in certain situations. I suppose once you head down that road at the drawing board you could end up in a never ending" what about 10 more gallons" and 10 more after that and 10 more after that until you end up with as someone said a flying fuel truck. I guess you have to draw the line somewhere and they drew it where the thought it needed to be but it does seem if modification for a small amount of additional fuel was possible later it certainly would have yielded large benefits. Maybe it wasn't practical or maybe it's one of those looks obvious with the benefit of hindsight but didn't seem so at the time things. One of those missed opportunities.


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## michael rauls (Jul 17, 2018)

wuzak said:


> Supermarine did try and stuff more fuel into the Spitfire over the years.
> 
> But the amount they could add was limited by the space available in the airframe.
> 
> ...


 That makes sense. If the fuselage is narrow in particular you you are limited as to how wide you can go with an additional tank and you can only go so far back before you run into serrious stability issues.


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## michael rauls (Jul 17, 2018)

wuzak said:


> Supermarine did try and stuff more fuel into the Spitfire over the years.
> 
> But the amount they could add was limited by the space available in the airframe.
> 
> ...


 It does sound like they did everything they could do within the limitations of the airframe. I guess at some point if you want more range you just need more space to put the fuel. I.e. a larger fuselage or thicker wings and both of those have downsides.


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## buffnut453 (Jul 17, 2018)

michael rauls said:


> It does sound like they did everything they could do within the limitations of the airframe. I guess at some point if you want more range you just need more space to put the fuel. I.e. a larger fuselage or thicker wings and both of those have downsides.



And a more powerful engine to lug all that extra weight and drag around the sky at equivalent performance to the smaller aircraft.

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## GrauGeist (Jul 17, 2018)

Also bear in mind that additional fuel in the fuselage (where ever it might be added) will have a direct effect on the CoG (center of gravity).

The Me262, for example, had two tanks in the fuselage, one ahead of the cockpit (at the gunbay's bulkhead) and one behind the cockpit. If the fuel was used from the rear tank first, it caused the 262 to become "nose heavy" in it's performance, so the procedure was to feed from the front tank first, then switch to the rear tank.

Many other types with similar fuselage fuel cell configurations had the same performance issues if fuel management wasn't properly followed.

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## pbehn (Jul 18, 2018)

All sorts of "stuff" was done or could have been. In addition to the leading edge tanks mentioned, there was a tank used in PR spits never used on fighters it went under the pilots seat. The Griffon engine moved things about and increased the forward tank capacity. However it seems to me things were not that pressing for more range until 1942 when the RAF started to receive the first Mustangs anyway. Another thing to bear in mind was the Typhoon was supposed to replace the Spitfire but never did. Work on the Spitfire MK VIII started in early 1942 but the FW 190 force the stop gap MK IX into production. The MK VIII had a low back, bubble canopy rear fuselage tank bigger front tank however in addition to carrying more fuel the later Merlin generally used more fuel.

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## wuzak (Jul 18, 2018)

pbehn said:


> All sorts of "stuff" was done or could have been. In addition to the leading edge tanks mentioned, there was a tank used in PR spits never used on fighters it went under the pilots seat. The Griffon engine moved things about and increased the forward tank capacity. However it seems to me things were not that pressing for more range until 1942 when the RAF started to receive the first Mustangs anyway.



Even with the Mustang, I don't believe the RAF was pushing that hard for extra fighter range. 




pbehn said:


> Work on the Spitfire MK VIII started in early 1942 but the FW 190 force the stop gap MK IX into production. The MK VIII had a low back, bubble canopy rear fuselage tank bigger front tank however in addition to carrying more fuel the later Merlin generally used more fuel.



Most VIIIs had the normal rear fuselage, not the cut down rear fuselage with bubble canopy.







Supermarine Spitfire (late Merlin-powered variants) - Wikipedia

Similarly, most XIVs had the standard rear fuselage, but some had the cut down rear fuselage with bubble canopy.

Even a few Mk XVIs (IX with Packard built Merlin 266) had the bubble canopy.

The VIII, being the definitive 2 stage Merlin Spitfire, had the fuel in the inner wing leading edges, the IX did without.

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## pbehn (Jul 18, 2018)

The whole thing is a dogs dinner Wuzak, I was talking about mainly what they intended, other things got in the way.


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## wuzak (Jul 18, 2018)

pbehn said:


> The whole thing is a dogs dinner Wuzak, I was talking about mainly what they intended, other things got in the way.



Hence the "interim" types - the V, IX and XIV - were produced in greater numbers than the "definitive" versions - the III. VII/VIII, 21.

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## pbehn (Jul 18, 2018)

wuzak said:


> Hence the "interim" types - the V, IX and XIV - were produced in greater numbers than the "definitive" versions - the III. VII/VIII, 21.


Much of the production was based on what they had in the factory, great fun for model makers but a bit confusing, a low back Mk VIII looks much more modern and advanced than most Mk XIV s


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## michael rauls (Jul 18, 2018)

pbehn said:


> All sorts of "stuff" was done or could have been. In addition to the leading edge tanks mentioned, there was a tank used in PR spits never used on fighters it went under the pilots seat. The Griffon engine moved things about and increased the forward tank capacity. However it seems to me things were not that pressing for more range until 1942 when the RAF started to receive the first Mustangs anyway. Another thing to bear in mind was the Typhoon was supposed to replace the Spitfire but never did. Work on the Spitfire MK VIII started in early 1942 but the FW 190 force the stop gap MK IX into production. The MK VIII had a low back, bubble canopy rear fuselage tank bigger front tank however in addition to carrying more fuel the later Merlin generally used more fuel.


 All very interesting. It's hard to imagine wanting to replace the spitfire with anything unless this was infact a quest for more range. I have read so many different statements as to the range of the Typhoon and its ultimate reincarnation the Tempest over the years I wouldn't even have an idea if this might be the case. Maybe as a replacement for the Huricane I can at least see the motivation but for the spit that kinda leaves me wondering what they were thinking.


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## pbehn (Jul 18, 2018)

michael rauls said:


> All very interesting. It's hard to imagine wanting to replace the spitfire with anything unless this was in fact a quest for more range. I have read so many different statements as to the range of the Typhoon and its ultimate reincarnation the Tempest over the years I wouldn't even have an idea if this might be the case. Maybe as a replacement for the Huricane I can at least see the motivation but for the spit that kinda leaves me wondering what they were thinking.


Both Hurricane and Spitfire were built to the same requirement. Supermarine were a sea plane and race plane company, they produced a high spec "racer". Hawkers being descended from Sopwith were a fighter company, they produced a low tech design that they knew they could produce in numbers. Before the war started Supermarine had produced so few Spitfires that they nearly lost the contract, Hawkers were producing Hurricanes so quickly the RAF couldn't form squadrons and train pilots quickly enough to accept them, they were allowed to sell it to other nations. Whatever the Hurricanes faults were, there was never a shortage of them in the early years.


The Hurricane was basically obsolete in 1940 but fighting on home ground with RADAR control and the boost that 100octane fuel allowed meant it could hold its own. The Spitfire as designed was obsolete in 1941/42. The two stage Merlin with the fuel needed to run it took the Merlin up to circa 2,000HP eventually. This was the power output projected for the next generation of fighters the which Hawkers started working on as soon as the Hurricane, flew the Typhoon and Tornado. The Tornado bit the dust when the Vulture was abandoned in favour of Merlin development, the Typhoon disappointed as an dodgy airframe with a problematic engine. Eventually the Tempest development of the Typhoon with a Sabre or Centaurus engine became one of the top performers of any piston aircraft, but only at low level, the Spitfire with a Griffon ran it close at low level but was much better at high altitude. Work on the Fury/Sea Fury started in 1942 and it flew in 1945, only the Sea Fury was produced but this certainly had longer range.


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## GrauGeist (Jul 18, 2018)

The Hurricane was to the British as the P-40 was to the U.S. - they were both available in solid numbers when the war started, they were able to hold their own in spite of shortcomings and they both saw service on virtually every front of the war.

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## michael rauls (Jul 18, 2018)

pbehn said:


> Both Hurricane and Spitfire were built to the same requirement. Supermarine were a sea plane and race plane company, they produced a high spec "racer". Hawkers being descended from Sopwith were a fighter company, they produced a low tech design that they knew they could produce in numbers. Before the war started Supermarine had produced so few Spitfires that they nearly lost the contract, Hawkers were producing Hurricanes so quickly the RAF couldn't form squadrons and train pilots quickly enough to accept them, they were allowed to sell it to other nations. Whatever the Hurricanes faults were, there was never a shortage of them in the early years.
> 
> 
> The Hurricane was basically obsolete in 1940 but fighting on home ground with RADAR control and the boost that 100octane fuel allowed meant it could hold its own. The Spitfire as designed was obsolete in 1941/42. The two stage Merlin with the fuel needed to run it took the Merlin up to circa 2,000HP eventually. This was the power output projected for the next generation of fighters the which Hawkers started working on as soon as the Hurricane, flew the Typhoon and Tornado. The Tornado bit the dust when the Vulture was abandoned in favour of Merlin development, the Typhoon disappointed as an dodgy airframe with a problematic engine. Eventually the Tempest development of the Typhoon with a Sabre or Centaurus engine became one of the top performers of any piston aircraft, but only at low level, the Spitfire with a Griffon ran it close at low level but was much better at high altitude. Work on the Fury/Sea Fury started in 1942 and it flew in 1945, only the Sea Fury was produced but this certainly had longer range.


 Seems like the spitfire had qualities that made more than competitive ( at least where the mission profile dictated that range wouldn't be a huge factor) like verry high critical mach, good general maneuverability, and at least competitive speed/ climb as engine horse power upgrades were made. Maybe roll rate was less than one would hope for? I would be fascinated to here the reasons you believe it to have bean obsolete so early on.


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## michael rauls (Jul 18, 2018)

GrauGeist said:


> The Hurricane was to the British as the P-40 was to the U.S. - they were both available in solid numbers when the war started, they were able to hold their own in spite of shortcomings and they both saw service on virtually every front of the war.


 Good way to put it. I didn't mean to disparage the Huricane in my earlier post( a very under appreciated type in my opinion as was the p40) just that I could see the reasons to be looking for a replacement by 40/41.


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## pbehn (Jul 18, 2018)

michael rauls said:


> Seems like the spitfire had qualities that made more than competitive ( at least where the mission profile dictated that range wouldn't be a huge factor) like verry high critical mach, good general maneuverability, and at least competitive speed/ climb as engine horse power upgrades were made. Maybe roll rate was less than one would hope for? I would be fascinated to here the reasons you believe it to have bean obsolete so early on.


Just the engine power output made it obsolete. At the time of its design, engine power was based mainly on swept volume and the Merlin was one of the smallest. The Mk V Spitfire was completely outclassed by the Fw190, without the extra power of a two stage supercharger and higher octane fuel it would never have closed the gap. With the wing tips removed the Spitfires roll rate wasn't too bad, its problem was the Fw 190 was exceptional. Within that there are huge generalisations, from the start to the end of the war the Spitfire doubled in weight, the wings mean they all look like Spitfires but they were very different planes just sharing similarities.

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## pbehn (Jul 18, 2018)

michael rauls said:


> Good way to put it. I didn't mean to disparage the Hurricane in my earlier post( a very under appreciated type in my opinion as was the p40) just that I could see the reasons to be looking for a replacement by 40/41.


It was only seen as a stop gap or interim solution even by Hawkers, as per my previous post Hawkers were working on its replacement(s) when the spec was issued in March 1938, the Hurricane just started being introduced in Dec 1937. The Tornado prototype first flew on 6 Oct 1939.


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## stona (Jul 18, 2018)

The Spitfire was the result of the quest for speed and firepower. Endurance (which people keep referring to as range) was consciously sacrificed in pursuit of the other two.
The result was actually a conflation of the specifications for two types of British fighters, 'zone' and 'interceptor' fighters. The Spitfire (and Hurricane) shared attributes of both whilst being neither. In reality both were a new type of interceptor, one that actually worked in Britain's developing coordinated system of air defence.
Cheers
Steve

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## Shortround6 (Jul 18, 2018)

I am not sure if endurance/range was actually sacrificed as much as it was pretty much left alone.
The Gloster Gladiator held 72 gallons of fuel, the Hawker Fury about 50 gals and the Hawker Demon about 73 gallons.
Granted their smaller engines used less fuel but a monoplane was going have a higher cruise speed even if throttled back. 
Endurance at the speeds used might be within 1/4 hour to 1/2 hour of each other (including Spits and Hurricanes?)
If you don't ask for higher endurance than existing fighters you aren't going to get it, especially if asking for large increases in speed and gun weight.

I would note in passing that as of Jan 1940 there were 18 fighter squadrons equipped (at least partially) with Blenheim MK IFs.
This means were more squadrons with Blenheims than with Spitfires.
Britain had a long range/high endurance fighter. It just wasn't very good (and it wasn't intended to be much more than a place holder for the Beaufighter).

They were also basically asking for monoplanes of over 300 MPH to operate out of the same sized airfields that the Biplanes operated out of.
Gladiator could take 320 to 450 yds to clear a 50 ft screen depending on engine/boost and prop and it took 420 yds to land from 50ft using the wheel brakes.
The Gladiators with 3 blade props used a metal fixed pitch prop.

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## fastmongrel (Jul 18, 2018)

Increasing fuel by 10 to 15% doesnt mean you get 10 to 15% extra range.

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## ClayO (Jul 19, 2018)

Another issue is manufacturing. The Spitfire and Hurricane were good enough during the BoB, the main problem was getting enough of them. 

In a production line, any change requires retooling, changes to documentation, procedures, testing, and so on. Early in the war there was no time for any of that. Another complication was the intermittent need to repair bomb damage to the Supermarine and Hawker factories: the quickest way to repair something is to put it back the way it was, not try to make improvements during the repair job.


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## Ivan1GFP (Jul 19, 2018)

michael rauls said:


> Seems like the spitfire had qualities that made more than competitive ( at least where the mission profile dictated that range wouldn't be a huge factor) like verry high critical mach, good general maneuverability, and at least competitive speed/ climb as engine horse power upgrades were made. Maybe roll rate was less than one would hope for? I would be fascinated to here the reasons you believe it to have bean obsolete so early on.



Regarding the Spitfire, there are a couple factors that I have not seen mentioned yet.
First of all, the Mk.V and Mk.IX were only "interim" versions but the "definitive" Mk.VIII was a heavier aircraft that did not perform quite as well. With the lighter Merlin engine, you really didn't need the extra structure as you might with the Griffon in the Mk.XIV.
I believe the revised wing structure with the versions such as Mk.21 did not really make it into the war so in this context may not be relevant.
Although the Spitfire had an excellent turn radius AND an excellent roll rate in later versions, its speed was always rather low for the installed power.
If you compare the Spitfire and Mustang with similar model engines, the Mustang is consistently about 30 MPH faster.
It took a Griffon engine Mk.XIV to match the speed of a Merlin Mustang.
Laminar flow wings, low drag and high speed at the possible cost of turn performance was preferred by the end of the war and the successor (Spiteful / Seafang) was a much higher speed aeroplane.

- Ivan.


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## pbehn (Jul 19, 2018)

Ivan1GFP said:


> Regarding the Spitfire, there are a couple factors that I have not seen mentioned yet.
> First of all, the Mk.V and Mk.IX were only "interim" versions but the "definitive" Mk.VIII was a heavier aircraft that did not perform quite as well. With the lighter Merlin engine, you really didn't need the extra structure as you might with the Griffon in the Mk.XIV.
> I believe the revised wing structure with the versions such as Mk.21 did not really make it into the war so in this context may not be relevant.
> Although the Spitfire had an excellent turn radius AND an excellent roll rate in later versions, its speed was always rather low for the installed power.
> ...


It has been discussed at length that the MkV and IX were interim versions on his and other threads. If you compare the P-51 with the Spitfire you find that the Spitfire was in service in 1939 while the P-51 with Allison engine first appeared at Dieppe in 1942. By this time the Spitfire had already made the wars highest interception at 43,000 ft, it was some time later that the P-51 appeared with the Rolls Royce engine that helped it make its name (late 1943). North American only ever contracted to produce a better fighter than the P-40. It was the British who ordered the Mustang, they received 500 Allison engined aircraft which were good bit not substantially better than aircraft in service like the Typhoon and Mk IX Spitfire.


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## Ivan1GFP (Jul 19, 2018)

pbehn said:


> It has been discussed at length that the MkV and IX were interim versions on his and other threads. If you compare the P-51 with the Spitfire you find that the Spitfire was in service in 1939 while the P-51 with Allison engine first appeared at Dieppe in 1942. By this time the Spitfire had already made the wars highest interception at 43,000 ft, it was some time later that the P-51 appeared with the Rolls Royce engine that helped it make its name (late 1943). North American only ever contracted to produce a better fighter than the P-40. It was the British who ordered the Mustang, they received 500 Allison engined aircraft which were good bit not substantially better than aircraft in service like the Typhoon and Mk IX Spitfire.



Hello Pbehn,
No disagreement from me on most of your points but please recognize that I wasn't saying that the Mustang was a "better" fighter.
What I was saying was that speed was somewhat lacking in the Spitfire as compared to contemporaries especially at low altitude.
It had advantages such as a very high climb rate but it also had some limitations because of its thin wing. The larger wheels that were needed for the heavier later models did not really fit entirely inside the thin wing. The ammunition capacity was low.

As for the Mustang, what people sometimes don't know is that even with the Allison engine, it was relatively fast at low altitude. The Mustang Mk.II (P-51A) was the fastest version below 10,000 feet until the P-51H came along. The P-51A was making the same true air speed at 15,000 feet as the Spitfire Mk.IX did at 25,000 feet. Think about what that means for an aeroplane with a single stage Allison to compare in that manner to a two stage Merlin and the difference in installed power. For what it's worth, although the Typhoon might catch an Allison Mustang at low altitude, the Spitfire Mk.IX doesn't even come close.

- Ivan.


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## pbehn (Jul 19, 2018)

Ivan1GFP said:


> Hello Pbehn,
> No disagreement from me on most of your points but please recognize that I wasn't saying that the Mustang was a "better" fighter.
> What I was saying was that speed was somewhat lacking in the Spitfire as compared to contemporaries especially at low altitude.
> It had advantages such as a very high climb rate but it also had some limitations because of its thin wing. The larger wheels that were needed for the heavier later models did not really fit entirely inside the thin wing. The ammunition capacity was low.
> ...


How is the Spitfire a contemporary? Only 500 Mustang Mk I arrived in UK with Allison engines. When did the Mustang Mk II (P-51A) appear in service? The contract was placed in June 1942 and 360 were built before production switched to P-51B/C, since it only performed at low level did it out perform Griffon Spitfire Mk XII which was in production from Oct 1942. How many P-51As (Mustang II) were deployed to Europe, they must have been needed if they were so much better than everything else.


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## Shortround6 (Jul 19, 2018)

rather than degenerate into another Spit vs P-51 argument, I do think it more interesting to stay on topic.
WHY were certain (or actually most) aircraft designed they way they were? 
Aerodynamic knowledge was advancing at frantic pace. Like for the Americans to go from this




First US Army aircraft with flaps at end of 1934/ beginning of 1935 to this 




Laminar flow and double slotted flaps.




by the summer of 1942. 7 1/2 years. 
Please note that the British Whitley started life without any flaps. They were added early in the development but too late to change that 8 1/2 degree downward tilt of the fuselage. These early flaps were pretty much airbrakes that added drag, they did little, if anything, for lift. 

New materials and heat treatments and new methods of fabricating parts. 

Size of airfields, types of fuel. Many things changed but since it took 2-4 years to bring a plane from sketches on paper to squadron service many planes were out dated on the day they first flew with an operational squadron. Only thing was it was going to take several years for the new prototype to reach squadron service.

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## pbehn (Jul 19, 2018)

It takes a war to turn pic 1 into pic 3.


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## wuzak (Jul 19, 2018)

Ivan1GFP said:


> Regarding the Spitfire, there are a couple factors that I have not seen mentioned yet.
> First of all, the Mk.V and Mk.IX were only "interim" versions but the "definitive" Mk.VIII was a heavier aircraft that did not perform quite as well. With the lighter Merlin engine, you really didn't need the extra structure as you might with the Griffon in the Mk.XIV.



The 2 stage Merlin was 250-300lb heavier than the single stage versions. It was also more powerful than the earlier versions. This is why the structure was strengthened. 

http://www.wwiiaircraftperformance.org/Spitfire_VIII_Tactical_Trials.pdf

Tactical trials between a IX and VIII (with extended wing tips) showed only small advantages for each - the VIII for speed over 30,000ft, the IX for climb rate at low altitudes. The biggest difference was in roll, where the extended wing tips and smaller ailerons on the VIII were detrimental.

But most production VIIIs had the standard wing tips, so performance would be very close.

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## Shortround6 (Jul 19, 2018)

pbehn said:


> It takes a war to turn pic 1 into pic 3.








Lockheed Super Electra first flight July 27th 1937. 
There were a number of other flap designs.


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## pbehn (Jul 19, 2018)

Shortround6 said:


> View attachment 502426
> 
> Lockheed Super Electra first flight July 27th 1937.
> There were a number of other flap designs.


I meant the rate of progress S/R, look at all the planes in production and on the drawing board in Sept 1939 and compare the same in Aug 1945.


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## MiTasol (Jul 20, 2018)

michael rauls said:


> Verry enlightening answers to things I have wondered about. I'm sure there are many more examples like this like leaving the supercharger off the p39 or p40 but I want to leave at least a few picks for others.



The P-39 and P-40 both have superchargers.
They do not have *turbochargers *although the P-39 was designed with one.


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## MiTasol (Jul 20, 2018)

michael rauls said:


> All good points. I was thinking that even a tiny increase in wieght of fuel could have huge benefits in certain situations. I suppose once you head down that road at the drawing board you could end up in a never ending" what about 10 more gallons" and 10 more after that and 10 more after that until you end up with as someone said a flying fuel truck. I guess you have to draw the line somewhere and they drew it where the thought it needed to be but it does seem if modification for a small amount of additional fuel was possible later it certainly would have yielded large benefits. Maybe it wasn't practical or maybe it's one of those looks obvious with the benefit of hindsight but didn't seem so at the time things. One of those missed opportunities.



To fit that extra ten gallons in a Spitfire main tank means making the tank longer and leaving out all the instruments and maybe the instrument panel. Pilots are known to bitch about various things and in this case it I think it would definitely be warranted.


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## michael rauls (Jul 20, 2018)

MiTasol said:


> The P-39 and P-40 both have superchargers.
> They do not have *turbochargers *although the P-39 was designed with one.


 Sorry i was referring to not upgrading to a two stage supercharger latter on when it was available. Guess I drastically missworded that. My bad.


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## michael rauls (Jul 20, 2018)

MiTasol said:


> To fit that extra ten gallons in a Spitfire main tank means making the tank longer and leaving out all the instruments and maybe the instrument panel. Pilots are known to bitch about various things and in this case it I think it would definitely be warranted.


 Could this not have been located behind the cockpit ala p51( an honest question not a retorical one). Might have caused some handling issues with the rear tank full like again the 51 but if this were used up in warm up/ take off the same way then the benefits would seem to out way the downside no?


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## pbehn (Jul 20, 2018)

michael rauls said:


> Could this not have been located behind the cockpit ala p51( an honest question not a retorical one). Might have caused some handling issues with the rear tank full like again the 51 but if this were used up in warm up/ take off the same way then the benefits would seem to out way the downside no?


There was a rear tank in some spitfires, it had the same issue as on the P-51. However this wouldn't solve the problem. The P-51 was faster on maximum speed, but it was also faster when cruising, on the same engine setting it was 30mPH quicker which is a long way on a 6 hr mission much of which is cruising. The Spitfire could use external slipper tanks of varying sizes, but the bigger the tank the more performance was affected, with the biggest slipper tank it was possible to fly to somewhere you cannot fly back from.


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## michael rauls (Jul 20, 2018)

pbehn said:


> There was a rear tank in some spitfires, it had the same issue as on the P-51. However this wouldn't solve the problem. The P-51 was faster on maximum speed, but it was also faster when cruising, on the same engine setting it was 30mPH quicker which is a long way on a 6 hr mission much of which is cruising. The Spitfire could use external slipper tanks of varying sizes, but the bigger the tank the more performance was affected, with the biggest slipper tank it was possible to fly to somewhere you cannot fly back from.


 So if I understand that corectly 10 gallons additional on a spitfire would not be enough to materially impact combat radius at least in some part due to a lower cruising speed as compaired the the p51 for instance. And just continueing on with the same lime of reasoning here, I'm guessing a maybe a larger tank mounted in the same manner would cause unacceptable instability issues on take off?


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## pbehn (Jul 20, 2018)

michael rauls said:


> So if I understand that corectly 10 gallons additional on a spitfire would not be enough to materially impact combat radius at least in some part due to a lower cruising speed as compaired the the p51 for instance. And just continueing on with the same lime of reasoning here, I'm guessing a maybe a larger tank mounted in the same manner would cause unacceptable instability issues on take off?


Cruising a Merlin uses 50 gals/hr, at maximum it uses 150galls hr. (as ball park figures). So it gives you an extra 12 minutes cruising or 6 minutes range about 25 miles.


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## michael rauls (Jul 20, 2018)

pbehn said:


> Cruising a Merlin uses 50 gals/hr, at maximum it uses 150galls hr. (as ball park figures). So it gives you an extra 12 minutes cruising or 6 minutes range about 25 miles.


 Seems an extra 12 minutes could have been more than useful in some situations or maybe say 18 minutes with a slightly larger tank if that was doable without causing to much of a instability on take off issue? but I suppose as was said earlier you have to draw the line somewhere with the fuel thing and guys alot smarter than me drew it where they thought it should go. I just can't help but think what an extra18 or even 12 minutes might have meant in alot of situations in a plane with a limited combat radius.


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## pbehn (Jul 20, 2018)

michael rauls said:


> Seems an extra 12 minutes could have been more than useful in some situations or maybe say 18 minutes with a slightly larger tank if that was doable without causing to much of a instability on take off issue? but I suppose as was said earlier you have to draw the line somewhere with the fuel thing and guys alot smarter than me drew it where they thought it should go. I just can't help but think what an extra18 or even 12 minutes might have meant in alot of situations in a plane with a limited combat radius.


The other side is what missions would a long range spitfire do? The RAF didn't have a suitable day bomber. A fighter doesn't do much damage on its own and in any case the Mustang MkI was ordered by the British who received 500 of them, they also had Typhoons to shoot up locos in France.


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## michael rauls (Jul 20, 2018)

pbehn said:


> The other side is what missions would a long range spitfire do? The RAF didn't have a suitable day bomber. A fighter doesn't do much damage on its own and in any case the Mustang MkI was ordered by the British who received 500 of them, they also had Typhoons to shoot up locos in France.


 Agreed. I think its fair to say, ya a little more endurance would have certainly been useful in some situations but you can't expect guys at the drawing board years earlier to envision every possible future situation especially when the mission profile they had in mind when designing the spit was not one that requires a particularly long range. So now I have a much better idea " why the heck did they designed it that way" Thanks!


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## Shortround6 (Jul 20, 2018)

You also have to remember that when many of these aircraft were designed (pencils/pens put to paper) self sealing tanks, armor and BP glass were not required. 
These added hundreds of pounds to fighters and often resulted in smaller fuel tanks. In some cases in 1940 the improvements in the engines barely kept pace with the increase inoperational weight let alone allowed large increases in fuel storage. Radio equipment was also added. For the British IFF so their own planes would show up on the ground radar as friendly is an often overlooked change.

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## buffnut453 (Jul 20, 2018)

The problem here is that we're applying the retrospectroscope and expecting people in 1936 to know how long(er)-range fighter-bombers would evolve when no such thing existed in the 1930s. 

All military procurement systems involve the levying of requirements for what is anticipated at that time. Sadly, our crystal balls aren't particularly effective and we often (usually?) find that we're fighting a different war than was expected. That's exactly what happened with the Spitfire. There was never any thought in the 1930s that bombers might need fighter escorts all the way from the UK to Berlin, nor was there any conception that a single-engine, single-seat fighter could carry a useful ground attack payload. 

The Spitfire was designed to defend the UK mainland or, if necessary forward deploy (almost inevitably to France) for coalition defensive operations. In those envisaged roles, I think it excelled. Sadly, as we now know, that isn't the way WW2 developed but, to me, it is testament to R J Mitchell's design genius that the Spitfire remained a potent threat, increasing performance, payload AND range throughout its evolution. That's a pretty impressive achievement in my book.

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## michael rauls (Jul 20, 2018)

Shortround6 said:


> You also have to remember that when many of these aircraft were designed (pencils/pens put to paper) self sealing tanks, armor and BP glass were not required.
> These added hundreds of pounds to fighters and often resulted in smaller fuel tanks. In some cases in 1940 the improvements in the engines barely kept pace with the increase inoperational weight let alone allowed large increases in fuel storage. Radio equipment was also added. For the British IFF so their own planes would show up on the ground radar as friendly is an often overlooked change.


 Yes thats one of the things that has always been kinda frustrating for me to read that for many types just as improvements in hp came along so would a wheelbarrow full of new required wieght
keeping them mired in never ending mediocre performance mud so to speak. Most of these things like self sealing fuel tanks certainly warranted the soaking up of new hp. However, although I can't remember any particular examples right now I reamember thinking of a couple weight additions" did they really need that extra 300 lbs for that". That might also be an interesting discussion i.e. modifications done to aircraft negatively affecting performance that ended up giving little if any benefit but i guess that would be another topic for another thread................Hmmmmm


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## stona (Jul 20, 2018)

Shortround6 said:


> I am not sure if endurance/range was actually sacrificed as much as it was pretty much left alone.



No, it was willingly sacrificed in the workings of the Operational Requirements Committee.
Everything about designing a fighter is a compromise, and in the quest for speed and firepower it was endurance that was one of the the first to be compromised.
Cheers
Steve
Edit: Wasn't fuel capacity/endurance further reduced when Supermarine agreed to fit eight guns? (I can't remember). The requirement to lift a bomb definitely went, in lieue of more guns.


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## michael rauls (Jul 20, 2018)

I certainly hope to hear others inquiries/ picks to be answered or spontaneous explanations given of reasons things were designed the way they were( not nescesarily limited to things that appeared to be deficits, at least at first glance) as I for one find this topic fascinating and this thread was not intended to be a "one off" for the Bf109/ Spitfire. I can think of dozens if not hundreds of examples but don't want to Bogart the thread.


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## Ivan1GFP (Jul 20, 2018)

pbehn said:


> How is the Spitfire a contemporary? Only 500 Mustang Mk I arrived in UK with Allison engines. When did the Mustang Mk II (P-51A) appear in service? The contract was placed in June 1942 and 360 were built before production switched to P-51B/C, since it only performed at low level did it out perform Griffon Spitfire Mk XII which was in production from Oct 1942. How many P-51As (Mustang II) were deployed to Europe, they must have been needed if they were so much better than everything else.



Seems like I hit a nerve here. That was not my intent.
To address your points though: The Mustang Mk.I actually should have been faster at low altitude but just could not break the 400 MPH mark at any altitude. The Mk.II P-51A could. I believe most of the very low production numbers served in CBI but I didn't realise we were restricting discussions to Europe.
Never said the Allison Mustang or Mustang in general was better than everything else.
The main point I was trying to make was that although the Spitfire was certainly a great fighter, it was relatively slow for the amount of engine power installed and the only other common aircraft with similar model engines was the P-51B/D. If you think about it, the Merlin Mustang had about the same speed advantage over the Spitfire Mk.IX as the Allison Mustang had over the P-40....

As I see it, in general, everyone has some kind of unusual feature in their fighter design: The Mid-Engine in P-39, Thin Elliptical Wings in Spitfire, Landing Gear attached to the Fuselage for Me 109. Sometimes the trade off worked and some times it did not.

Just to throw another Aeroplane into the pot: What do you all think of the relatively small wings on the Focke-Wulf 190 series?

- Ivan.


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## michael rauls (Jul 20, 2018)

Ivan1GFP said:


> Seems like I hit a nerve here. That was not my intent.
> To address your points though: The Mustang Mk.I actually should have been faster at low altitude but just could not break the 400 MPH mark at any altitude. The Mk.II P-51A could. I believe most of the very low production numbers served in CBI but I didn't realise we were restricting discussions to Europe.
> Never said the Allison Mustang or Mustang in general was better than everything else.
> The main point I was trying to make was that although the Spitfire was certainly a great fighter, it was relatively slow for the amount of engine power installed and the only other common aircraft with similar model engines was the P-51B/D. If you think about it, the Merlin Mustang had about the same speed advantage over the Spitfire Mk.IX as the Allison Mustang had over the P-40....
> ...


 I've wondered if the small wings on the FW190 were an intentional( an apparently successful) attempt to create a higher roll rate.


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## Ivan1GFP (Jul 20, 2018)

michael rauls said:


> Yes thats one of the things that has always been kinda frustrating for me to read that for many types just as improvements in hp came along so would a wheelbarrow full of new required wieght
> keeping them mired in never ending mediocre performance mud so to speak. Most of these things like self sealing fuel tanks certainly warranted the soaking up of new hp. However, although I can't remember any particular examples right now I reamember thinking of a couple weight additions" did they really need that extra 300 lbs for that". That might also be an interesting discussion i.e. modifications done to aircraft negatively affecting performance that ended up giving little if any benefit but i guess that would be another topic for another thread................Hmmmmm



Hello Michael Rauls,
A really great example of this kind of degeneration would be the P-39 Airacobra.
As designed, and up to the P-39C, it carried 170 Gallons of fuel which isn't bad for an interceptor.
Armament, armour, and other military equipment would add about 1000 pounds to the design weight.
Add in some self sealing fuel bags and fuel load is down to 120 Gallons in the same space.
Weight escalations elsewhere (I believe mostly in the Engine and Supercharger) and an apparent wish to keep the aircraft weight low would reduce the fuel load to only 87 Gallons by the time the P-39N came along. That is barely half of what it started with....

Perhaps the small wings on the FW 190 helped the roll rate and perhaps they did not. Even with the longer wings of he Ta 152 series, the roll rate was still quite good.

- Ivan.

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## michael rauls (Jul 20, 2018)

Ivan1GFP said:


> Hello Michael Rauls,
> A really great example of this kind of degeneration would be the P-39 Airacobra.
> As designed, and up to the P-39C, it carried 170 Gallons of fuel which isn't bad for an interceptor.
> Armament, armour, and other military equipment would add about 1000 pounds to the design weight.
> ...


 Yes good example. I would think the f4f/fm2 would be another prime example of this. My thinking about the small wings on the Fw190/ roll rate, with my limited understanding of aerodynamics, was that all other things being equal less wing area would create less resistance and therefore a quicker roll rate. At least to start. I could be wrong( often am) but didn't aircraft with a higher wing loading for about the same size aircraft generally have better roll rates?


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## michael rauls (Jul 20, 2018)

Didn't the D have long wings but thin so still a fairly small area?


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## Shortround6 (Jul 20, 2018)

stona said:


> No, it was willingly sacrificed in the workings of the Operational Requirements Committee.
> Everything about designing a fighter is a compromise, and in the quest for speed and firepower it was endurance that was one of the the first to be compromised.
> Cheers
> Steve
> Edit: Wasn't fuel capacity/endurance further reduced when Supermarine agreed to fit eight guns? (I can't remember). The requirement to lift a bomb definitely went, in lieue of more guns.



You may have actual documents/letters/memos, etc. I certainly do not. 
I am just pointing out that the Hurricane and Spitfire, with internal fuel, were going to have roughly the same endurance (not necessarily range) as the biplanes they were replacing as their bigger engine would use more fuel per hour. They may have bit more range as their cruising speed would be higher than the biplanes cruising speed so distance covered per hour would be different but not be enough to call for or allow a difference in tactics or differences in patrol/intercept areas or distances. 

the "standard" bomb load of most British fighters of the 20s and early 30s seems to have been four 20lb bombs? Essentially unchanged since the S.E.5 if not before. Since the monoplanes with fixed pitch props were cutting it a bit close in take-off and landing distances without hanging little bombs under them it seems sensible to delete them.


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## michael rauls (Jul 20, 2018)

By thin i meant fron to back.


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## stona (Jul 20, 2018)

The Spitfire was originally supposed to lift a 250 lb bomb.
Obviously later Marks could, and some, but the capability was deleted from the Mk I.
Cheers
Steve


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## Shortround6 (Jul 20, 2018)

Thank you, I had not seen that before.


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## pbehn (Jul 20, 2018)

Ivan1GFP said:


> Seems like I hit a nerve here. That was not my intent.
> To address your points though: The Mustang Mk.I actually should have been faster at low altitude but just could not break the 400 MPH mark at any altitude. The Mk.II P-51A could. I believe most of the very low production numbers served in CBI but I didn't realise we were restricting discussions to Europe.
> Never said the Allison Mustang or Mustang in general was better than everything else.
> The main point I was trying to make was that although the Spitfire was certainly a great fighter, it was relatively slow for the amount of engine power installed and the only other common aircraft with similar model engines was the P-51B/D. If you think about it, the Merlin Mustang had about the same speed advantage over the Spitfire Mk.IX as the Allison Mustang had over the P-40....
> ...


You seem to miss my point, the P-51 and Spitfire were both British aircraft until the US military took an interest, even then they were both allied aircraft. It makes no sense to make the Spitfire compete in range when you actually have the Mustang and also the Typhoon then Tempest. The Spitfire Mk XIV first started in service in Oct 1943.

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## michael rauls (Jul 20, 2018)

pbehn said:


> You seem to miss my point, the P-51 and Spitfire were both British aircraft until the US military took an interest, even then they were both allied aircraft. It makes no sense to make the Spitfire compete in range when you actually have the Mustang and also the Typhoon then Tempest. The Spitfire Mk XIV first started in service in Oct 1943.


 Verry good point that made me realize I all to often view aircraft, especially allied aircraft, in terms of their individual atributes and or shortcomings in certain areas and not how they fit into the larger scheme of things.


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## pbehn (Jul 20, 2018)

michael rauls said:


> Verry good point that made me realize I all to often view aircraft, especially allied aircraft, in terms of their individual atributes and or shortcomings in certain areas and not how they fit into the larger scheme of things.


US pilots were flying Spitfires in UK until replaced by more suitable US aircraft, the RAF operated P-51B/C and D sometimes assisting on bomber escort, US P-51s also escorted Mosquitos on some bombing missions. It was an allied effort, particularly in photo recon, it made no sense to be anything else.

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## buffnut453 (Jul 20, 2018)

pbehn said:


> US pilots were flying Spitfires in UK until replaced by more suitable US aircraft, the RAF operated P-51B/C and D sometimes assisting on bomber escort, US P-51s also escorted Mosquitos on some bombing missions. It was an allied effort, particularly in photo recon, it made no sense to be anything else.



You raise a good point. Equally, AFAIK, the USAAF wasn't providing fighter defences for the UK mainland which, again, demonstrates that this was an integrated Allied effort.

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## Shortround6 (Jul 20, 2018)

We have a lot of things going on in this discussion.

The Mustang I may never have been designed/intended as a long range airplane in the way we think now.

It was also four years newer (at least) than either the Spitfire or the P-40 in knowledge.
The first production P-40 (no letter) flew only 1 month before the British OK'ed the preliminary drawings for the Mustang I. NAA was pitching a better P-40, not a better Spitfire. A P-40 (no letter) without self sealing tanks held 180 gallons of fuel. This went down to 160 gallons on the first rudimentary self sealing tanks and down even further later. And please note that the performance figures for the early P-40 was based on 120 gallons US of fuel (99 Imp gal)
http://www.wwiiaircraftperformance.org/P-40/P-40_Official_Summary_of_Characteristics.pdf

Not with the rear tank full.

The initial Mustang I design _may _have been done accordingly. Performance estimates done on something less than full tank/s. with the full tanks being available for deploying or transfers? spring of 1940 is before drop tanks were common in either the US or UK. Things change fast in wartime and by the time they were delivered and issued they may have decided to take the hit to speed/climb and fill the tanks. 

As far as the Typhoon goes, I am not at all sure that it was _designed_ as a "long range" fighter. Design work starting in 1937/38 and 154imp gallons (in what became self sealing tanks) really doesn't provide a lot of range/endurance for a 2000hp engine in a fighter the size of the Typhoon. Pilot's manual calls for about 4.5 miles to gallon at 230mph IAS at 15,000ft when clean. Going to 280mph IAS at 15,000ft clean drops the mileage to about 3.5 miles per gallon.

It may very well have gone further than a Spitfire but it was hardly going to be a an escort fighter for bombers attacking Germany from the UK in 1940-41(planning and initial development).

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## pbehn (Jul 20, 2018)

Another point to consider in design is home territory, in England it is impossible to be further than 72 miles from the sea, I believe it is slightly more in the USA. Even in peace time how many times would a Spitfire have to refuel flying coast to coast? In UK if high enough you can frequently see both coasts.


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## Ivan1GFP (Jul 20, 2018)

pbehn said:


> You seem to miss my point, the P-51 and Spitfire were both British aircraft until the US military took an interest, even then they were both allied aircraft. It makes no sense to make the Spitfire compete in range when you actually have the Mustang and also the Typhoon then Tempest. The Spitfire Mk XIV first started in service in Oct 1943.



Hello Pbehn,
This was not intended as a Spitfire versus Mustang discussion or even a comparison of the two aircraft other than for the simple characteristic of speed.
If you look at the original post I was replying to, you will note that it was a discussion of the characteristics of the Spitfire.
Why the heck did they design it that way?

While I agreed with most of what was stated, two of the characteristics did not seem correct to me.
I chose to address the "at least competitive speed" comment which I believe was not correct.
Is there another aircraft with a comparable engine that can be compared to the Spitfire?
I suppose one could consider how much faster an early Spitfire is to a Hurricane, but that is a waste of time.
The Merlin Mustang makes a pretty good comparison though because both were equipped with the same engine at about the same time.

The other factor I was intending to comment about was the roll rate. The Spitfires with metal ailerons especially those with clipped wings had a VERY fast roll rate. (About 150 degrees per second at 200 MPH IAS) They were not quite as fast as the FW 190, but were better than nearly anything else flying. In fact, up to a bit past 200 MPH, they actually rolled faster in a steady state than the FW 190. The non clipped wing versions were not that bad either. (About 105 degrees per second at 200 MPH IAS) This beats the vast majority of fighters of the time.

- Ivan.

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## Shortround6 (Jul 20, 2018)

Just saw these great pictures
by Terry in the "*Flying Legends 2018"* thead.










Please note the angle of the flaps.
They are doing just about nothing for lift and are acting as air brakes (drag producers and/or lift spoilers).
This was rather common for flaps designed in the mid 30s. You still needed a big wing for take-off but the flaps kept you from floating down the runway for a long distance on landing and steepened the glide angle/approach angle.

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## pbehn (Jul 20, 2018)

Ivan1GFP said:


> Hello Pbehn,
> This was not intended as a Spitfire versus Mustang discussion or even a comparison of the two aircraft other than for the simple characteristic of speed.
> If you look at the original post I was replying to, you will note that it was a discussion of the characteristics of the Spitfire.
> Why the heck did they design it that way?
> ...


But time is everything. The twin stage supercharger merlin engined Spitfire was in service with the RAF before the Allison engined Mustang. By the time the Merlin engined P-51 appeared in service in UK the front line Spitfire had a two stage Griffon. Prior to the P-51D going into service the RAF had the Tempest and Meteor in service. As S/R has said there is no doubt that the P-51 had superior aerodynamics, not just the laminar flow wings but also the cooling set up made better use of the Meredith effect and had lower drag anyway, plus the all around fit of joints. My point was about what was contemporary with what. I said the Spitfire with clipped wings had a good rate of roll compared to most, this would have been of little comfort to its pilots who were actually facing the Fw 190.

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## Ivan1GFP (Jul 20, 2018)

pbehn said:


> But time is everything. The twin stage supercharger merlin engined Spitfire was in service with the RAF before the Allison engined Mustang. By the time the Merlin engined P-51 appeared in service in UK the front line Spitfire had a two stage Griffon. Prior to the P-51D going into service the RAF had the Tempest and Meteor in service. As S/R has said there is no doubt that the P-51 had superior aerodynamics, not just the laminar flow wings but also the cooling set up made better use of the Meredith effect and had lower drag anyway, plus the all around fit of joints. My point was about what was contemporary with what. I said the Spitfire with clipped wings had a good rate of roll compared to most, this would have been of little comfort to its pilots who were actually facing the Fw 190.



Hello Pbehn,
WHY are you trying to make this into a Spitfire versus Mustang argument?
All I will state for the record is that the two aircraft are quite different in many characteristics.
I actually agree with the details of your posts but the point is that we are NOT discussing the same thing.
My point was that the Spitfire was relatively slow for the amount of installed engine power. Do you disagree with that?

- Ivan.


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## pbehn (Jul 20, 2018)

Ivan1GFP said:


> Hello Pbehn,
> WHY are you trying to make this into a Spitfire versus Mustang argument?
> All I will state for the record is that the two aircraft are quite different in many characteristics.
> I actually agree with the details of your posts but the point is that we are NOT discussing the same thing.
> ...


Yes. for the reasons I have set out at length. Speed was only ever one criteria of the Spitfire, it was an interceptor, rate of climb was another, as was firepower and time of front line service. Start at September 1939 and detail when it was second best and to what.


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## MiTasol (Jul 20, 2018)

Re post #68 (quoting is not working today)

Yes they could have added a ten gallon tank behind the pilot but then you add extra weight (wich degrades performance), a lot of extra plumbing (fuel and vent), an additional fuel selector position (which affects spares interchangeability), increase the possibility of the engine going quiet during some stage of operation due to fuel starvation, increased chance of leakage due to damage, etc.

Worse still, if this tank very small tank is used for start and taxi there is the possibility during a scramble that the pilot will fail to change tanks at the end of the runway resulting in the engine going quiet about the time the aircraft leaves the ground giving the pilot little or no chance of survival.

The other option of drop (slipper) tanks was used on the Spitfire but the design of those was far from perfect because they were an airfoil pointing down meaning they cancelled a portion of the aircraft's lift at a time when increased lift was required to compensate for the increased weight.

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## michael rauls (Jul 20, 2018)

If I can throw in my 2 cents( and that may be exactly what it's worth). The idea of the spitfire being slow sounds a little odd to me. The early models had a speed of about 360 near as I can tell. Not a rocket exactly but can't think of alot of planes that were much faster in 40/41. If I remember right the later Griffin jobss were close to 450. Sounds pretty good to me. Certainly not what I would characterise as slow. Just my take.

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## pbehn (Jul 20, 2018)

michael rauls said:


> If I can throw in my 2 cents( and that may be exactly what it's worth). The idea of the spitfire being slow sounds a little odd to me. The early models had a speed of about 360 near as I can tell. Not a rocket exactly but can't think of alot of planes that were much faster in 40/41. If I remember right the later Griffin jobss were close to 450. Sounds pretty good to me. Certainly not what I would characterise as slow. Just my take.


That is exactly the point, not only 1940 but 1939. At the time of its introduction it was a competitive front line interceptor/fighter with anything allied or enemy in outright performance, this situation continued throughout the war with the exception of late 1941 thro' to 1942 with the Fw190 and later the jet age.

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## MiTasol (Jul 20, 2018)

Shortround6 said:


> You also have to remember that when many of these aircraft were designed (pencils/pens put to paper) self sealing tanks, armor and BP glass were not required.
> These added hundreds of pounds to fighters and often resulted in smaller fuel tanks. In some cases in 1940 the improvements in the engines barely kept pace with the increase in operational weight let alone allowed large increases in fuel storage. *Radio equipment was also added. For the British IFF so their own planes would show up on the ground radar as friendly is an often overlooked change.*



And to put that weight increase into perspective, starting June 1945 the RAAF with their P-51's removed the fuselage fuel tank when they installed the IFF and vice versa. As well as the unit itself you have to add the shelving and in some cases reinforce the structure that the shelf attaches to.

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## fastmongrel (Jul 20, 2018)

The Royal Aircraft Establishment did a lot of testing on Spitfires with a view to increasing speed. Things like fitting an internal armoured glass screen gave iirc about 8mph extra, gloss paint 2 mph, removing the ice shield from the intake gave 4 mph, sanding panel joints 3 mph, flush fuselage rivets 2 mph. There was quite a list of things that added 1 or 2 mph. Eventually they got a fairly well used MkIX up from about 400 mph to about 425mph.

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## MiTasol (Jul 20, 2018)

Another example of the effect of adding the SCR-695 IFF is covered in this post on Mustangs.
Zoukei Mura P-51D
This may look like a minor change but structurally and wiring wise it was far from.

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## Ivan1GFP (Jul 20, 2018)

michael rauls said:


> If I can throw in my 2 cents( and that may be exactly what it's worth). The idea of the spitfire being slow sounds a little odd to me. The early models had a speed of about 360 near as I can tell. Not a rocket exactly but can't think of alot of planes that were much faster in 40/41. If I remember right the later Griffin jobss were close to 450. Sounds pretty good to me. Certainly not what I would characterise as slow. Just my take.



Hello Michael Rauls,
My comment wasn't so much that the Spitfire was slow. It was that it was relatively slow for the installed power.
The point is that with enough power ANYTHING can be made quite fast.
Consider that a Spitfire needed a Griffon engine to reach the speed of a Merlin P-51B.
I will admit that comparison to the Mustang is a hard one to win because the Mustang had unusually good aerodynamics, but with a little hindsight, perhaps we should compare it against another contemporary airframe: The Messerschmitt 109 or Hispano Buchon.
There are a few flying today with Merlin engines. I believe they are flying with Merlin 45's which would make them about equivalent to a Spitfire Mk.V for engine power. By my understanding, they are a lot faster than a Spitfire Mk.V.

- Ivan.


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## pbehn (Jul 20, 2018)

Ivan1GFP said:


> Hello Michael Rauls,
> My comment wasn't so much that the Spitfire was slow. It was that it was relatively slow for the installed power.
> The point is that with enough power ANYTHING can be made quite fast.
> Consider that a Spitfire needed a Griffon engine to reach the speed of a Merlin P-51B.
> ...


For someone who doesn't want to make the discussion about the Spitfire versus Mustang you manage to introduce the Mustang fairly early in every post. Comparison is easy, 1939 no Mustang 1940 no Mustang, 1941 No Mustang, 1942 Mustang Mk 1 appears after Spitfire Mk IX, 1943 Merlin P51 appears alongside Griffon Spitfire, 1944 Me262, Meteor and Tempest in service.

As for the Spitfire versus Buchon, another aircraft you have introduced while wanting to discuss the Spitfire, please advise where your "understanding" comes from?

Has the Mustang airframe with a Merlin Mk III and a fixed pitch two blade prop been evaluated to see if it could get airborne?


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## michael rauls (Jul 20, 2018)

Ivan1GFP said:


> Hello Michael Rauls,
> My comment wasn't so much that the Spitfire was slow. It was that it was relatively slow for the installed power.
> The point is that with enough power ANYTHING can be made quite fast.
> Consider that a Spitfire needed a Griffon engine to reach the speed of a Merlin P-51B.
> ...


 I understand your point and its a good one perhaps when it comes to fuel consumption per mile. But as far as outright performance wouldn't the airframe design capable of housing the high hp engine, using the resulting hp in an effective manner i.e. still able to maneuver well and be stable at the higher speeds, and by extension the verry engine itself an integral part of the design? Again I'm certainly no expert but thats how it looks to me.


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## michael rauls (Jul 20, 2018)

If I could put it another way whatever gave a specific aircraft " performance" whether that be speed due in part to higher hp or say long range due to a laminar flow wing in part, arent all those things just part of the design and the performance is what it is as a result of all those factors and all those factors are part of the design by definition. I mean wouldn't saying any plane would be fast if you put a big engine on it be kinda like saying any plane could be long range if you slap a laminar flow wing on it. Again im no expert but just an observation.


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## pbehn (Jul 20, 2018)

michael rauls said:


> If I could put it another way whatever gave a specific aircraft " performance" whether that be speed due in part to higher hp or say long range due to a laminar flow wing in part, arent all those things just part of the design and the performance is what it is as a result of all those factors and all those factors are part of the design by definition. I mean wouldn't saying any plane would be fast if you put a big engine on it be kinda like saying any plane could be long range if you slap a laminar flow wing on it. Again im no expert but just an observation.


Lamellar flow was a development, just like jet engines were. You cannot transplant them back years before they existed to declare an earlier design to be primitive. Before the Mustangs laminar flow wings ever saw service the Spitfire had played its part in winning the Battle of Britain Malta and North Africa. The Mosquito did not have 5 digit NACA wing profiles but it did have advanced RAF profiles and a cooling system and other aerodynamics on par with a P-51....but it wasn't in service in 1939.

RAF airfoils?
RAF 34 AIRFOIL (raf34-il)


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## michael rauls (Jul 20, 2018)

pbehn said:


> Lamellar flow was a development, just like jet engines were. You cannot transplant them back years before they existed to declare an earlier design to be primitive. Before the Mustangs laminar flow wings ever saw service the Spitfire had played its part in winning the Battle of Britain Malta and North Africa. The Mosquito did not have 5 digit NACA wing profiles but it did have advanced RAF profiles and a cooling system and other aerodynamics on par with a P-51....but it wasn't in service in 1939.
> 
> RAF airfoils?
> RAF 34 AIRFOIL (raf34-il)


 Yes i agree with everything in your post. I was ruminating on Ivans statement that" any plane would be fast if you put a larger engine in it" by answering isn't the engine and the airframe capable of housing it an integral part of the design and the resulting performance( of the spitfire in this case) be a result of all those design factors including but not limited to the engine. To further the point that all those factors are indeed a part of the design I pointed out that the statement that" any plane can be fast if you put a larger engine in it" ignores the fact( at least in my mind) that the engine IS a part of the design of the spitfire just as much as the lamellar flow wing was part of the mustang by pointing out that, in my opinion, saying "any aircraft could be fast if you put a larger engine in it" is perhaps the same as saying any plane could be long range if you slap a lamellar flow wing on it to give an example of why i thought this statement to be perhaps missing the larger picture, in my opinion.

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## Shortround6 (Jul 20, 2018)

The Spitfire falls on spectrum of speed vs power installed. Yes it is worse than Mustang, but then so is just about everything else and anything that falls between the Spitfire and the Mustang has some serious limitations of it's own.
The 109E had a parachute behind compared to the Spitfire. It's "low drag" is due to it being a much smaller airplane and when *extensively* modified into the 109F 
(you might be hard pressed to take a 109E wreck and "restore" it into an F) it picked up around 20mph or more using the same engine (most got improved engines) 
Obviously the Hurricane wasn't exactly low drag. The P-40 was actually pretty good. It's main failing wasn't streamlining (drag) but weight which affected climb (and other things).
Something that often gets left out is the effect of armament on fighter design. The guns and ammo of a 1930s fighter were it's payload and the weight and size of the armament package sometimes dictated the aircrafts layout (P-39 for example) but more often the size of the wing and other considerations. 
In the mid 30s with a field length of a certain size if you doubled the number of guns and amount of ammunition then you might need another 6-12 sq feet of wing to provide the necessary lift, except that additional wing area might cost 3lbs a square or so in structural weight. landing gear and tires might need beefing up. 
Once a plane is in production and especially after the shooting starts the customer (air force) often turned a blind eye to somethings going a few percentage points over the line but in prototype form things could get ugly if a pane didn't meet performance specifications.

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## michael rauls (Jul 20, 2018)

michael rauls said:


> Yes i agree with everything in your post. I was ruminating on Ivans statement that" any plane would be fast if you put a larger engine in it" by answering isn't the engine and the airframe capable of housing it an integral part of the design and the resulting performance( of the spitfire in this case) be a result of all those design factors including but not limited to the engine. To further the point that all those factors are indeed a part of the design I pointed out that the statement that" any plane can be fast if you put a larger engine in it" ignores the fact( at least in my mind) that the engine IS a part of the design of the spitfire just as much as the lamellar flow wing was part of the mustang by pointing out that, in my opinion, saying "any aircraft could be fast if you put a larger engine in it" is perhaps the same as saying any plane could be long range if you slap a lamellar flow wing on it to give an example of why i thought this statement to be perhaps missing the larger picture, in my opinion.


 Ya sometimes it takes me a few tries to assemble my thoughts in an orderly manner and put them in writing.


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## pbehn (Jul 20, 2018)

Shortround6 said:


> Once a plane is in production and especially after the shooting starts .


That is when everything changes, many aircraft remained in production purely because changing to something else means nothing for a long time then something a bit better later.


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## Shortround6 (Jul 20, 2018)

The Spitfire was also subject to a number of modifications, some rather ham handedly done. Much is made of the somewhat low performance of the MK V.
However not only did the MK V go from eight .303s to the two 20mm with the associated increase in weight and drag (protruding barrels and assorted lumps and bumps on the wing) but you had the infamous external BP wind screen on some aircraft and other small details that cost a few mph each. Build quality may have been something of a factor? at least for some of 1941?

I would note that the Mk V went from about 6450lbs for a MK VA with eight .303s to (and the fastest at 375mph) to 6525lbs for Vb (with drums?) to 6965 lbs for a Vc with a universal wing (and interior BP windscreen) and speed was down to about 360mph. Tropical filters and other things could bring down the speed considerably.

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## Ivan1GFP (Jul 20, 2018)

pbehn said:


> Has the Mustang airframe with a Merlin Mk III and a fixed pitch two blade prop been evaluated to see if it could get airborne?



The Spitfire was a much lighter airframe which is where a lot of its performance came from. I am actually pretty sure it actually could get airborne but maybe not in a reasonable length runway. If you want to take that argument a little further, then how about a 100 HP engine that would easily get a Fokker biplane airborne but has no hope of powering a heavier aeroplane?

If you really want to compare airframes, then take a look at what has been run in the "Unlimited Class" air races. An Airacobra won in 1946, the P-40Q has raced though it crashed, Corsairs, Bearcats, Mustangs, Sea Furies race these days. Many of those planes don't have Laminar Flow wings either. When was the last time you saw a Spitfire race? Does it even have a chance of being competitive there? I don't believe we have ever seen a Hellcat or a regular P-40 race either.

As for actual fighter aircraft rather than racers, the problem with getting higher performance with a bigger and more powerful engine is that it will probably be heavier, have higher fuel consumption and range gets even shorter.

- Ivan.


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## pbehn (Jul 21, 2018)

buffnut453 said:


> You raise a good point. Equally, AFAIK, the USAAF wasn't providing fighter defences for the UK mainland which, again, demonstrates that this was an integrated Allied effort.


The RAF was always responsible for UK defence. Things happened very quickly as far as daylight escort forces were concerned. The first P-51Bs to arrive were assigned to fighter groups and didn't have the rear tank. They also didn't have pilots. There was a chart of pilot US training which showed that the final stage of training was done in theatre, Chuck Jaeger certainly did. So at least in mid to late 1943 these squadrons were more like OTUs. The US forces were training for what they had to do, linking them in to the UK defence system and requiring them to keep the sky clear while they were training on type is a bit of an imposition. I have no idea if the LW did try sneak daylight attacks in 1943 they certainly had a few goes infiltrating the night bomber streams.

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## Shortround6 (Jul 21, 2018)

Ivan1GFP said:


> The Spitfire was a much lighter airframe which is where a lot of its performance came from. I am actually pretty sure it actually could get airborne but maybe not in a reasonable length runway. If you want to take that argument a little further, then how about a 100 HP engine that would easily get a Fokker biplane airborne but has no hope of powering a heavier aeroplane?
> 
> If you really want to compare airframes, then take a look at what has been run in the "Unlimited Class" air races. An Airacobra won in 1946, the P-40Q has raced though it crashed, Corsairs, Bearcats, Mustangs, Sea Furies race these days. Many of those planes don't have Laminar Flow wings either. When was the last time you saw a Spitfire race? Does it even have a chance of being competitive there? I don't believe we have ever seen a Hellcat or a regular P-40 race either.
> 
> ...


Using air racers, especially the 1946-47 ones, as a benchmark doesn't actually tell us much. Many of the racers just used what they could buy cheap as surplus and sometimes it what they had flown in the war. They familiar with it. It took a few years to sort out what was competitive and what was not, and the hobby guys without much money tended to get left behind. Spitfires were more than a little hard to come by in US scrap and surplus sales. You could spend more shipping a surplus Spitfire from England than it cost to by an entire US fighter (with fuel still in the tanks) so yes, foreign aircraft were scarce.
By 1948 it took deep pockets and or sponsorship to get to the front of the pack although a few hobby flyers still showed up.
The Airacobra was as close to factory racer as you could get. Prep work was done in a Bell hanger by Bell employees in their off duty time with consulting done by Bell engineers. It may not have been paid for by Bell but no other race team in 1946-47 had that level of technical expertise.

The Problem with using the later racers as indicators of actual WW II performance is that many of the later ones were extensively modified. In fact even some of the last of the early racers were a far cry form stock condition.
despite this a Spitfire Mk XIV, stock except for gun and armor removal, finished 3rd in the 1949 Tinnerman Trophy race behind a F2G-1 Corsair and a P-51K








(Aaron King photo)
from 1949 National Air Races
One of the more extensively modified Mustangs was Bill Odum's




Radiators moved to pods on the wing tips. 

Someplanes had some serious wing clipping going on.



(Aaron King photo)

On some planes the fuel mixture was not standard aviation fuel. Cook Clelands Corsairs sometimes used Triptane to allow around 4000hp.




another modified Mustang.



(Bill Meixner Collection) 

Back then surplus warplanes were cheap and plentiful.
Nowadays Warbirds are rare, expensive and valued too highly to chop up into competitive racers.

The other thing about race results is that the manifold pressure and RPM are rarely mentioned so even if running standard AVgas, we don't know what the actual power levels were and some racers were satisfied just to compete and win some prize money to offset their costs and have a working engine/airplane to race another day rather than go for broke for first place.


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## pbehn (Jul 21, 2018)

I seem to remember some P-51s being fitted with Griffon engines? Schurley Schome Mishtayke?


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## davparlr (Jul 21, 2018)

Shortround6 said:


> Just saw these great pictures
> by Terry in the "*Flying Legends 2018"* thead.
> 
> Please note the angle of the flaps.
> ...



I had some personal experience to how effective flaps are as drag devices. C-141s had huge Fowler flaps with two settings Takeoff/Approach and Landing. Takeoff/Approach was mostly lift and Landing was mostly drag. We were deep into our 12 hour crew duty day and were very tired from flying what we called European shuttle, taking off from Torrejon AB, Madrid, we already gone to several places in Europe, typically Greece, Cyprus, Naples, and were now flying into Piza with a follow-on leg back to Torrejon. We were told by center to contact Piza tower for hand off. We tried several times to contact Piza to no avail. Due to this, we had to execute a low altitude penetration or procedure turn to ILS. Still no contact so we continued our approach and ran the check list, flaps approach, pause, gear down, before landing check list. Finally Pisa cleared us for landing, I called flaps landing (to be done when landing was assured) and started to land. Approach was normal and flare was normal. The plane would not settle on the runway. It floated, and floated, and floated. We were half way down the runway and I decided I'd better get the mains on the runway so I slightly lowered the nose and the plane settled on the runway. The C-141 also had massive anti-lock brakes and I knew it would haul it down and it did. On after landing check list, we discovered that the copilot had failed to put the flaps in landing and I had failed to check. It was a bit nerve wracking. What if that runway had been shorter. Fatigue, broken timelines, out of normal operations, are some of the things pilots have to be especially alert to.

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## Ivan1GFP (Jul 21, 2018)

Shortround6 said:


> Using air racers, especially the 1946-47 ones, as a benchmark doesn't actually tell us much. Many of the racers just used what they could buy cheap as surplus and sometimes it what they had flown in the war. They familiar with it. It took a few years to sort out what was competitive and what was not, and the hobby guys without much money tended to get left behind. Spitfires were more than a little hard to come by in US scrap and surplus sales. You could spend more shipping a surplus Spitfire from England than it cost to by an entire US fighter (with fuel still in the tanks) so yes, foreign aircraft were scarce.
> By 1948 it took deep pockets and or sponsorship to get to the front of the pack although a few hobby flyers still showed up.
> The Airacobra was as close to factory racer as you could get. Prep work was done in a Bell hanger by Bell employees in their off duty time with consulting done by Bell engineers. It may not have been paid for by Bell but no other race team in 1946-47 had that level of technical expertise.



Hello Shortround6,
Yes, I agree. Comparing racing configurations is a bit of a stretch, but in later years it does illustrate a bit of the limitations of the airframes.
As I see it, a NACA 2200 series airfoil does have some nice handling characteristics, but isn't really optimal for high speed, and speed was the only point I was trying to make that seems to have gotten a really good argument going.
The racing Cobras were an interesting story but one has to also remember the outcome despite the technical expertise and resources available to the team:
These folks were improvising just like everyone else. Their engines and propellers were surplus King Cobra units. Jack Woolams, the primary pilot, died from an apparent structural failure when testing Cobra 1. This conclusion is supported by the additional bracing added to Cobra 2 piloted by Tex Johnston who was the eventual winner of the race that year.

Quite a few of those racing planes ended up as smoking holes in the ground.



Shortround6 said:


> The Problem with using the later racers as indicators of actual WW II performance is that many of the later ones were extensively modified. In fact even some of the last of the early racers were a far cry form stock condition.
> despite this a Spitfire Mk XIV, stock except for gun and armor removal, finished 3rd in the 1949 Tinnerman Trophy race behind a F2G-1 Corsair and a P-51K



I had forgotten about that appearance of the Spitfire. If you look at the speeds achieved, they are somewhat indicative of the point I was trying to make though:
F2G: 386 MPH
P-51: 379 MPH
Spitfire: 359 MPH

As you had commented on, modification are much more extensive today than in the past with much larger budgets.
We see Griffon powered Mustangs such as Red Baron (RIP) and R-3350 powered Bearcats and Corsairs. We see Hawker Sea Furies.
What we don't see is Spitfires, Hellcats, P-40s, P-38s, Thunderbolts and other airframes that may have made for great fighters but have limitations for absolute speed. While one can argue that Spitfires are a bit hard to find, if they really had a potential advantage, someone would most likely have found a rebuildable one to use as a racer. Just look at the Super Corsair (RIP) to see where it started from.
The point as before is that for the same amount of engine power, a Spitfire is only about average for speed. I figure from a speed standpoint, it has about the same potential as a P-40.

- Ivan.


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## pbehn (Jul 21, 2018)

Are the Griffon Mustangs faster?


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## pbehn (Jul 21, 2018)

Ivan1GFP said:


> The Spitfire was a much lighter airframe which is where a lot of its performance came from. I am actually pretty sure it actually could get airborne but maybe not in a reasonable length runway. If you want to take that argument a little further, then how about a 100 HP engine that would easily get a Fokker biplane airborne but has no hope of powering a heavier aeroplane?
> 
> If you really want to compare airframes, then take a look at what has been run in the "Unlimited Class" air races. An Airacobra won in 1946, the P-40Q has raced though it crashed, Corsairs, Bearcats, Mustangs, Sea Furies race these days. Many of those planes don't have Laminar Flow wings either. When was the last time you saw a Spitfire race? Does it even have a chance of being competitive there? I don't believe we have ever seen a Hellcat or a regular P-40 race either.
> 
> .


This is pure fanboyism. The Spitfire is a lightweight design because it had to be, with the early Merlin engines and propellers it had to take off in a reasonable distance. The P-51 airframe is approaching a ton heavier than the comparable Spitfire MIX. You discount the fact that it was in service in 1939 while the Allison engined Mustang appeared in late 1942 as immaterial. You emphasise its performance at low level with the Allison engine ignoring the fact that it didn't perform at all at high levels. When fitted with a Merlin engine the P-51 had good performance but the Merlin was a bigger engine, the Griffon was just a bigger engine. The P-51 as mustang I,II,III or IV was never the top performer in the RAF at any altitude at any time during the war. It did have prodigious range when fitted with an extra tanks inside and out but the drawback to that is the size and weight of the fuselage. The British had need of front line fighters before the Autumn of 1943.


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## buffnut453 (Jul 21, 2018)

Ivan1GFP said:


> I had forgotten about that appearance of the Spitfire. If you look at the speeds achieved, they are somewhat indicative of the point I was trying to make though:
> F2G: 386 MPH
> P-51: 379 MPH
> Spitfire: 359 MPH



The ONLY thing that indicates is that, on that particular day, these were the results achieved for those 3 specific airframes. I'd like to know the composition of the entire race, that way we'd know if/how many P-51s and Corsairs were beaten by the Spitfire to achieve this 3rd place position.






Ivan1GFP said:


> While one can argue that Spitfires are a bit hard to find, if they really had a potential advantage, someone would most likely have found a rebuildable one to use as a racer.


Because finding a Spitfire and getting it to the States was a lot more expensive and harder than just finding an unused or slightly used P-51 or F4U that were sitting in their thousands at airfields across the US. Cost and availability are key drivers that cannot be ignored in this context.​




Ivan1GFP said:


> The point as before is that for the same amount of engine power, a Spitfire is only about average for speed. I figure from a speed standpoint, it has about the same potential as a P-40.



So you base that on one race, from an example that hadn't been extensively modified from its wartime configuration and power performance? And the Spitfire has the same speed potential as a P-40? Please feel free to carry on figuring in your fantasy world of miniscule sample sets. ​


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## Shortround6 (Jul 21, 2018)

Most of these air races had numbers too small to signify much. This particular race/event only had 9 entrants, two of which dropped out during the race and two did not start.
The Spitfire did beat, rather handley an F-5 (P-38) and a P-38. which were down under 330mph. A P-51A dropped out on the 7th lap and another P-38 dropped out on the 3rd lap. 
The SOHIO event also had 9 entrants, all finished.
Fastest was that highly modified Mustang at 388mph,
2nd was one of Cleland Cooks F2Gs at 384mph
3rs was a P-63 at 381mph
4th was a P-51D at 376
5th was a P-51D at 373mph
6th was a P-63 at 359mph 
7th was a P-51D at 349mph
8th was a P-63 at 330mph 
and last was a P-39Q at 329mph. 

What can we "learn" from this? 
1. The P-39Q was about as fast as a P-63 
2. P-63s were faster than P-51Ds 
3. Corsairs with over 3000hp are faster than Mustangs with under 2000hp? 

Btw 1949 saw the only other entry of a non American plane in the National air races of this time. 
In the Bendix (Cross country from Rosamond Dry Lake, CA.) to Cleveland Ohio, Mustangs finished 1,2,3 with a MK 25 Mosquito finishing a distant 4th. 
A Martin B-26 failed to finish before the deadline after landing for repairs and an Seversky AT-12 dropped out in Gran Junction CO. 
The Mosquito suffered from failures of the oxygen system and one engine near the end of the race.
The winner





" Joe DeBona 
an ex Air Force pilot flying the Bendix for the third time, flew a P-51B Mustang sponsored by actor 
Jimmy Stewart. His P-51C was refinished with no less than 48 coats of primers and gloss cobalt blue
paint. Polished to a high shine, the paint job reportedly added 8 mph to the speed of the aircraft. 
A special propeller was installed. It was designed to increase the speed of Air Force Mustangs up to
10 mph but rejected because its service life was too short. Joe's wet wing racerfavored by tailwinds 
of 28 to 33 mph and great navigation brought him into the winners circle at Cleveland."

again from 1949 National Air Races
He did average 470mph. 

What does this tell us?

A modified Mustang (wet wing) with special finish and special propeller flying at an unknown altitude with tail winds can beat a Mosquito flying at unknown altitudes with unknown tailwinds (pilots choose their own specific routes and cruise altitudes) that suffers equipment failures.

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## Shortround6 (Jul 21, 2018)

From the 1946 race;
Paul Mantz sought advice from Kelly Johnson of Lockheed on how to the wing the Bendix cross country race. Johnson advised to him "wet the wing". Fill all openings, seal the inside of the wing and fill it with gasoline. Mantz may or may not have thought of the trick of wrapping dry ice around the fuel filler hose to chill the fuel as the tanks were filled. In any case the modified Mustang held 875 gallons without drop tanks.


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## Ivan1GFP (Jul 21, 2018)

pbehn said:


> This is pure fanboyism. The Spitfire is a lightweight design because it had to be, with the early Merlin engines and propellers it had to take off in a reasonable distance. The P-51 airframe is approaching a ton heavier than the comparable Spitfire MIX. You discount the fact that it was in service in 1939 while the Allison engined Mustang appeared in late 1942 as immaterial. You emphasise its performance at low level with the Allison engine ignoring the fact that it didn't perform at all at high levels. When fitted with a Merlin engine the P-51 had good performance but the Merlin was a bigger engine, the Griffon was just a bigger engine. The P-51 as mustang I,II,III or IV was never the top performer in the RAF at any altitude at any time during the war. It did have prodigious range when fitted with an extra tanks inside and out but the drawback to that is the size and weight of the fuselage. The British had need of front line fighters before the Autumn of 1943.



Hello Pbehn,
Don't you think name-calling is a bit rude?
I am finding this discussion extremely strange because it all started with an observation (correct or not is for each to decide on his/her own) that the Spitfire wasn't a particularly fast aeroplane for the amount of installed power. I find it particularly funny that you accuse me of being a "fanboy" when the reality is that I have a much higher opinion of the Spitfire as an air-superiority fighter than I do of Mustangs in general and the Merlin Mustang in particular. Why does this speed issue bother you so much?

As for Griffon Mustangs, I believe the racing versions were reaching into the low 500 MPH range at very near Sea Level.



buffnut453 said:


> The ONLY thing that indicates is that, on that particular day, these were the results achieved for those 3 specific airframes. I'd like to know the composition of the entire race, that way we'd know if/how many P-51s and Corsairs were beaten by the Spitfire to achieve this 3rd place position.



I am actually in agreement with you on this point. Shortround6 already posted the rest of the results.
Everyone was a bit faster than stock but the question is how much faster.
With stock aircraft I would have expected the spread to be less but the same order of finish with a very close call between the Mustang and Spitfire.
Please note though that it was a Griffon Spitfire that raced and not a Merlin Spitfire.
Pylon racing is at low altitude and at low altitude, a Merlin Spitfire is surprisingly slow.



buffnut453 said:


> Because finding a Spitfire and getting it to the States was a lot more expensive and harder than just finding an unused or slightly used P-51 or F4U that were sitting in their thousands at airfields across the US. Cost and availability are key drivers that cannot be ignored in this context.



This may have been true for the early post war races, but is much less true today. That is why I mentioned the "Super Corsair". It started off in pretty poor condition before all the work was done to it. If the Spitfire had some speed advantage, the cost would not stop people today.​



buffnut453 said:


> So you base that on one race, from an example that hadn't been extensively modified from its wartime configuration and power performance? And the Spitfire has the same speed potential as a P-40? Please feel free to carry on figuring in your fantasy world of miniscule sample sets.


​
I don't know if you saw the beginning of the discussion but the original comparison was between a Spitfire Mk.IX and a P-51B. Both aircraft are running engines that are pretty near identical and yet there is about a 30 MPH speed difference. The comparison with a P-40 came about because at one point the P-51 and P-40 used identical engines as well. The difference there is that the earlier Allison Mustang was a bit more slick than the later Merlin versions, so draw your own conclusions from that.

- Ivan.


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## pbehn (Jul 21, 2018)

Ivan1GFP said:


> Hello Pbehn,
> Don't you think name-calling is a bit rude?
> I am finding this discussion extremely strange because it all started with an observation (correct or not is for each to decide on his/her own) that the Spitfire wasn't a particularly fast aeroplane for the amount of installed power. I find it particularly funny that you accuse me of being a "fanboy" when the reality is that I have a much higher opinion of the Spitfire as an air-superiority fighter than I do of Mustangs in general and the Merlin Mustang in particular. Why does this speed issue bother you so much?
> As for Griffon Mustangs, I believe the racing versions were reaching into the low 500 MPH range at very near Sea Level.
> .


The discussion is strange because the topic is why was the Spitfire designed as it was. It was designed as it was because of what was available and known in the mid 1930s and what it was required to do. You continually throw in the P-51 which was designed a generation later, the laminar flow wing was as much a new technology as the constant velocity prop, two stage supercharger and 130 octane fuel are. You cannot have a P-51 with laminar flow wings in 1939 the engines and aerofoils didn't exist. It is you who has the obsession with speed, you completely dismiss rate of climb, harmony of controls and turn performance then leap onto "reno racers". By the time the P-51 B entered service both the UK and Germany had jets flying, by the time the P-51D entered service both the British and Germans had jets in service, what relevance has a reno racer, all the Reno prop planes are slower than a Meteor and Me262 If you are quoting the speed of Griffon engined Mustangs at Reno, then Reno isn't at sea level, it is about 4,500ft.


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## pbehn (Jul 21, 2018)

One eternal mystery to me was the US introducing fighters with "birdcage" canopies long after the Spitfire and Fw190 were in service with "Malcolm hood" and type bubble canopies, even as a layman the advantage is obvious.


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## Ivan1GFP (Jul 21, 2018)

Hello Pbehn,

I do see the points you are trying to make, but you are also forgetting that my original reply was to a comment about speed of the Spitfire. The Mustang was only brought in as an illustration. As for the "not invented yet" descriptions, I believe you are incorrect about mot of those and that some of them are somewhat irrelevant.
1. Constant Speed propellers were in service long before the war started and yet the early British fighters didn't have them.
2. Perhaps the specific Laminar flow airfoils used on Mustang et al. were not yet used, but contemporaries of the Spitfire used other more "Modern" airfoils. Basically this was a choice. Perhaps there was a reason most of the folks used a 23000 series airfoil? Other folks also made some rather interesting and unusual choices.
3. Multi-stage superchargers may not have been a common thing but the Spitfire made a name for itself without one.... at least to start.
Every other common fighter started that way as did Mustang and P-40.
4. As for 100 octane gasoline, a fellow name Jimmy Doolittle did a fair bit on that subject well before Spitfire existed.

I am actually not particularly obsessed with speed. I just pointed out an observation and got a surprisingly energetic objection. The most interesting thing was that the objection was not so much against what I had actually stated but against what I had NOT stated. The racing aircraft only were brought into the discussion to suggest that if an airframe is seen to have good speed potential, the experts would probably have used it.



pbehn said:


> ....
> It is you who has the obsession with speed, you completely dismiss rate of climb, harmony of controls and turn performance then leap onto "reno racers".



I actually wasn't doing a general comparison between two aircraft. Why are you assuming (incorrectly) that I am dismissing the other factors when I didn't? This wasn't a discussion of merit. It was only a simple assertion about relative speeds of two aircraft with the same engine.
Now keep in mind that I am not really disagreeing with your assertion about qualities of Spitfire, but that isn't really the entire story either.
If you read Captain Eric Brown's evaluations, you also might note that he thought the FW 190 had excellent control harmony.
Tactical evaluations of Spitfire Mk.IX versus FW 190A give the maneuverability advantage to FW "except for turning circles".
There is also a minor issue of Longitudinal instability in the early model Spitfires that was addressed in later models with changing the aerodynamic balance of the elevator. Since I haven't flown a Spitfire personally, I can't claim great personal knowledge, but there is a video of Mark Hanna (RIP) flying a Spitfire Mk.IX very low and constantly making control corrections.
The point here is that every aircraft has its issues.

Regarding birdcage canopies:
That is a goofy thing isn't it? At least from a tactical standpoint. From an aerodynamic standpoint, the Malcom hood had a small speed penalty.
There is no question what the better design was for a fighter but at least on the Spitfire, I like the appearance better without the Bubble Top.
Perhaps this question should also be asked about other aircraft designed during the same period. The Hurricane never got anything better, and Tornado and Typhoon didn't start with anything particularly good either. Airacobra started with a good design as did Hayabusa and A6M. It also took a long time before Spitfire and Corsair got the more modern Bubble canopy. I wonder what a Me 109 would look like with a Bubble Top.

- Ivan.


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## pbehn (Jul 21, 2018)

Ivan1GFP said:


> Hello Pbehn,
> 
> I do see the points you are trying to make, but you are also forgetting that my original reply was to a comment about speed of the Spitfire. The Mustang was only brought in as an illustration. As for the "not invented yet" descriptions, I believe you are incorrect about mot of those and that some of them are somewhat irrelevant.
> 1. Constant Speed propellers were in service long before the war started and yet the early British fighters didn't have them.
> ...


1 Yes, but not on fighters, and it was peacetime, Rolls Royce and Bristol formed a company to develop their own, De Havilland also started developing them. 
2 The P51 aerofoils are not truly laminar flow, they were just better than previous developments. 
3 Yes the single stage supercharger did OK in 1940 it was outclassed in 1941/42 by the Fw190. It was the Mk IX with the two stage supercharger that took the Spitfire back to the frontline in 1942 and the P-51 a little over a year later.
4 Not 100 octane 130, the Merlin ended on 150 with the Hornet


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## pbehn (Jul 21, 2018)

Ivan1GFP said:


> I actually wasn't doing a general comparison between two aircraft. Why are you assuming (incorrectly) that I am dismissing the other factors when I didn't? This wasn't a discussion of merit. It was only a simple assertion about relative speeds of two aircraft with the same engine.
> 
> Regarding birdcage canopies:
> That is a goofy thing isn't it? At least from a tactical standpoint. From an aerodynamic standpoint, the Malcom hood had a small speed penalty.
> ...


But you were, you repeatedly talk about "The Spitfire" why not start at the Spitfire Mk21 and work backwards?


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## Shortround6 (Jul 21, 2018)

The British air ministry (or the dolt in charge of propellers) should have been summarily shot for either treason or criminal malfeasance.

Rotol and De Havilland were making variable pitch propellers pretty much in the face of official disapproval. Fedden ahd Hives knew they were needed and would be needed in numbers when the war came. 
It wa not only fighters. way, way to many British bombers got two pitch propellers years after not only invantly variable but constant speed props were available.
Way, way too many British multi engine aircraft had to put up with putting the prop on a dead engine in course pitch and using a propeller brake rather than being able to feather the prop on the dead engine. Not all constant speed props are fully feathering. 
And many British planes had to use props with a limited amount of pitch change. 20 degrees is not really enough for fast aircraft. 

Laminar flow is relative, the Davis airfoil used on the B-24 was sometimes described as laminar flow and it was nowhere near the improvement the P-51 wing was. 

there were two RR single stage superchargers in 1940. The Pre Hooker one used on the Merlin III, VIII, X and few others and the Hooker one used on the XX and the 45 and few others. The FW 190 might have been a bit less of problem had they mounted Merlin XX engines in Spitfires and allowed a bit higher boost sooner. 

British 87 octane may have been a bit better than some other peoples. In any case British 100 octane during the BoB was actually 100/115-120. American 100 octane in 1940 was 100/98-102. That is right, some American 100 octane (lean) was less than 100 octane when running rich.


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## pbehn (Jul 21, 2018)

Shortround6 said:


> The British air ministry (or the dolt in charge of propellers) should have been summarily shot for either treason or criminal malfeasance.
> 
> Rotol and De Havilland were making variable pitch propellers pretty much in the face of official disapproval. Fedden ahd Hives knew they were needed and would be needed in numbers when the war came.
> It wa not only fighters. way, way to many British bombers got two pitch propellers years after not only invantly variable but constant speed props were available.
> ...


As a law of unintended consequences maybe the early fighters developed for the RAF without constant speed props were lighter than they would have been and therefore better performing in the end?


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## pbehn (Jul 21, 2018)

Shortround6 said:


> Just saw these great pictures
> by Terry in the "*Flying Legends 2018"* thead.
> View attachment 502510
> 
> ...


For take of from carriers flying to Malta the landing flaps were modified to take off flaps by wedging them part closed, after take off the flaps were fully opend to drop the wedges and then closed.


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## pbehn (Jul 21, 2018)

Shortround6 said:


> British 87 octane may have been a bit better than some other peoples. In any case British 100 octane during the BoB was actually 100/115-120. American 100 octane in 1940 was 100/98-102. That is right, some American 100 octane (lean) was less than 100 octane when running rich.


That sounds a bit complicated S/R obviously well understood by all parties in 1939?


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## redcoat (Jul 21, 2018)

buffnut453 said:


> Because finding a Spitfire and getting it to the States was a lot more expensive and harder than just finding an unused or slightly used P-51 or F4U that were sitting in their thousands at airfields across the US. Cost and availability are key drivers that cannot be ignored in this context.​


Only 1 Spitfire was ever sold to a civilian by the British government and that was due to a lot of fudging of the governments policy guidelines on the sale of military aircraft, while the USA was happy to sell hundred's of P-51's to civilian buyers post-war

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## Shortround6 (Jul 21, 2018)

actually it wasn't. The performance number scale hadn't been developed yet. They had no real way of measuring anything over 100 octane except to say 100 octane + 1cc lead, 100 octane +2 cc of lead and so on. 
The British KNEW there was a difference in rich mixture response _*if* _the fuel contained a fair amount of aromatics. To get this unspecified result they required the 100 octane to be made with not less than 20% aromatics but not all aromatics act the same so fuel batch A with 10% automatic X and 10% aromatic Y might act the same running lean as batch B that had 12% X but 8% aromatic Z but batch B might be several percentage points better when running rich. 
They had discovered this difference back with the 87 octane if not before with batches of fuel coming from different refineries or oil fields. Some batches allowed higher power or more boost when running rich than others but they had no way to test the fuel except in service engines. 
The aromatics tend to dissolve certain rubber compounds so the US required fuel to contain NO MORE than 2% aromatic compounds. The US had to change a lot of gaskets and rubber components when they combined fuel specifications with the British. 

Again, there is a lot of confusion about "american fuel" in the BoB, a lot of the fuel came from the "The Americas" which is not the same as "America". Think of England as America and the British Isles as the "The Americas" British had a large oil refinery in Trinidad refining both local fuel and fuel from South/Central America.

Pouring American 100 octane into a Spitfire and trying to pull 12lbs boost might have lead to a nasty surprise. 

An awful lot of work was done on fuels in a short period of time in 1940-41. 

In theory 100/130 fuel allows for 30% higher pressures (or more power)* in the cylinders *than 100 octane fuel. But since you need more power to run the supercharger to get the higher pressure and few other losses you don't get 30% more power to the propeller.

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## pbehn (Jul 21, 2018)

Shortround6 said:


> actually it wasn't. The performance number scale hadn't been developed yet. They had no real way of measuring anything over 100 octane except to say 100 octane + 1cc lead, 100 octane +2 cc of lead and so on.
> The British KNEW there was a difference in rich mixture response _*if* _the fuel contained a fair amount of aromatics. To get this unspecified result they required the 100 octane to be made with not less than 20% aromatics but not all aromatics act the same so fuel batch A with 10% automatic X and 10% aromatic Y might act the same running lean as batch B that had 12% X but 8% aromatic Z but batch B might be several percentage points better when running rich.
> They had discovered this difference back with the 87 octane if not before with batches of fuel coming from different refineries or oil fields. Some batches allowed higher power or more boost when running rich than others but they had no way to test the fuel except in service engines.
> The aromatics tend to dissolve certain rubber compounds so the US required fuel to contain NO MORE than 2% aromatic compounds. The US had to change a lot of gaskets and rubber components when they combined fuel specifications with the British.
> ...


S/R I knew the answer I just cant explain it myself, in short "Its Complicated, extremely complicated", and trying and eventually succeeding in harmonising these fuel requirements was one of the many successes of the war, easily said and much harder to do.

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## Shortround6 (Jul 21, 2018)

pbehn said:


> S/R I knew the answer I just cant explain it myself, in short "Its Complicated, extremely complicated", and trying and eventually succeeding in harmonising these fuel requirements was one of the many successes of the war, easily said and much harder to do.




It is a bit difficult trying to condense several hundred pages worth of aviation fuel history into a few paragraphs. but yes, it was extremely difficult. It got much harder as the demand for fuel skyrocketed and choices had to be made about allowable levels of both lead and aromatic compounds in fuel as opposed to the amount of steel and building requirements needed by refineries to manufacture the needed fuel, one change in lead allowed was supposed to have saved enough steel to build ten destroyers if I remember right. The piping in refineries being a higher grade steel than freighter hulls. 

Anda s most planners, they were trying to think 6 months to year ahead and not react to a shortage this week or next.

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## pbehn (Jul 21, 2018)

Shortround6 said:


> It is a bit difficult trying to condense several hundred pages worth of aviation fuel history into a few paragraphs. but yes, it was extremely difficult. It got much harder as the demand for fuel skyrocketed and choices had to be made about allowable levels of both lead and aromatic compounds in fuel as opposed to the amount of steel and building requirements needed by refineries to manufacture the needed fuel, one change in lead allowed was supposed to have saved enough steel to build ten destroyers if I remember right. The piping in refineries being a higher grade steel than freighter hulls.
> 
> Anda s most planners, they were trying to think 6 months to year ahead and not react to a shortage this week or next.


I fully understand the concept if not the detail S/R, I worked for years on mechanically and metallurgically bonded oil/gas pipes. These cost much more than plain high yield carbon steel, but save a fortune on corrosion inhibitors, putting them in and taking them out. It is all much much more complicated than a single post can explain.


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## michael rauls (Jul 21, 2018)

Another interesting pick for"why the heck did they design it that way" is the p47 and its limited range. I know extra fuel is extra wieght and therefore degrading of performance but it seems if ever there was a plane with the space, need, and a little performance to spare especially at high altitude it was the p47. This one is a real head scratcher for me.


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## MiTasol (Jul 22, 2018)

Shortround6 said:


> The British air ministry (or the dolt in charge of propellers) should have been summarily shot for either treason or criminal malfeasance.



Years ago (about 1973) I bought a book on the history of the guns of the RAF. I have been trying to find a replacement copy for the last ten years.

According to it many of the directives regarding aircraft guns were made, not by the RAF _experts _but by Army _experts_. And that these _experts _grounded all the canon armed Spitfires for a few days early in the BoB until Hispano could prove that the breach was locked when the gun fired because the army prohibited the use of blowback weapons.

One of the lines I remember from the book is that these very modern up to date policy wonks made the statement "_there is a place for cavalry in modern warfare so long as it is thoroughbreds ridden by gentlemen_" in early 1939. These same wonks ensured the 1939 budget contained more money for hay for horses than fuel for vehicles, tanks, etc.

If this is correct it is not surprising that the RAF were against constant speed props and other non-British inventions. Don't forget the original Spitfire had fixed landing gear.

To quote Wiki _In 1931 the Air Ministry released specification F7/30, calling for a modern fighter capable of a flying speed of 250 mph (400 km/h). R. J. Mitchell designed the Supermarine Type 224 to fill this role. The 224 was an open-cockpit monoplane with bulky gull-wings and a large, fixed, spatted undercarriage powered by the 600 horsepower (450 kW), evaporatively cooled Rolls-Royce Goshawk engine.[5] It made its first flight in February 1934.[6] Of the seven designs tendered to F7/30, the Gloster Gladiator biplane was accepted for service.[7]_

Across the pond Donald Douglas started design of the DC-1 at the same time and the prototype made its maiden flight on July 1, 1933 - eight months before the Supermarine 224. The DC-1 had all metal structure, retractable gear and variable pitch props and was only 40mph slower than the 224 - and also carried 15 persons in a fully enclosed cabin. Boeing's competing model 247 was also all metal, retractable and fitted with variable pitch propellers. 

Britain's top line fighter chosen that year was the fixed gear, fixed pitch and fabric covered Gladiator biplane.

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## Shortround6 (Jul 22, 2018)

michael rauls said:


> Another interesting pick for"why the heck did they design it that way" is the p47 and its limited range. I know extra fuel is extra wieght and therefore degrading of performance but it seems if ever there was a plane with the space, need, and a little performance to spare especially at high altitude it was the p47. This one is a real head scratcher for me.



It is not a head scratcher, it is a change in operational requirements. The P-47 was NOT designed as a_ long range escort fighter_. 
And with the original 305 gallons internal the P-47 could fly roughly* twice* as far as a Spitfire or 109 at similar speeds and altitudes. 
It turned out that when the plane went into service nearly 3 years after initial design work started even that range was nowhere near enough. 
The P-47 could fly roughly the same distance at the same speed and altitude as a P-40 with the P-40 having a full behind the seat tank which was an overload tank. Not to be fully filled when doing maneuvers.

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## pbehn (Jul 22, 2018)

michael rauls said:


> Another interesting pick for"why the heck did they design it that way" is the p47 and its limited range. I know extra fuel is extra wieght and therefore degrading of performance but it seems if ever there was a plane with the space, need, and a little performance to spare especially at high altitude it was the p47. This one is a real head scratcher for me.


Is there an aeroplane whose range was satisfactory, one that the P-47 should have been designed to match?


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## Shortround6 (Jul 22, 2018)

MiTasol said:


> Years ago (about 1973) I bought a book on the history of the guns of the RAF. I have been trying to find a replacement copy for the last ten years.
> 
> According to it many of the directives regarding aircraft guns were made, not by the RAF _experts _but by Army _experts_. And that these _experts _grounded all the canon armed Spitfires for a few days early in the BoB until Hispano could prove that the breach was locked when the gun fired because the army prohibited the use of blowback weapons.
> 
> ...




I can forgive the Supermarine type 224





as at the time nobody else was using retractable landing gear either except the Russian I-16 and the Russians weren't talking. 
While this flew in 1932 it wasn't placed in Squadron service until 1935.




In the case of the Supermarine aircraft we have another case of officials screwing things up. The AIr Ministries "preferred" engine was the RR Goshawk. From wiki so usual disclaimer. 
"Specification F.7/30, which was formally issued to the aircraft industry in October 1931, called for an all-metal day and night fighter armed with four machine guns, a high top speed and rate of climb, and a landing speed of less than 60 mph. The importance of a good view from the cockpit was made clear. Although the use of any power plant was permitted, the Air Ministry did express a preference for the evaporatively cooled Rolls-Royce Goshawk then being developed."

The Goshawk engine was a Kestrel that was modified for 'evaporative cooling'. The water was allowed to turn to steam and was then condensed back to water.
This was supposed to allow for a lighter, more effective cooling system but it never worked and doomed any plane that used it to either failure or major rebuild. 
The Choice of the Gladiator was the result of the 4 aircraft using the Goshawk engine all failing. That and the Gladiator could be built using some of the tooling from the Gauntlet so it could be produced quickly after the long delay in coming up with a replacement for the Bristol Bulldog. 




First flown 1927, into service in 1929 and still equipping 8 of the RAFs 14 fighter squadrons in Jan 1935. 
If they had let the designers/manufacturers use a normal Kestrel things might have gone quicker.


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## michael rauls (Jul 22, 2018)

pbehn said:


> Is there an aeroplane whose range was satisfactory, one that the P-47 should have been designed to match?


 No not nescesarily. Just a curiosity hence the question. I guess the answer in the case of the p47 is more that the need for more range sprang up later and wasn't know at the time of development as opposed to the bf109 and spitfire which were a combination of this and space, wieght limitations, and possibly cog/stability issues with a larger tank if I understood everyones responses corectly.
That's what's interesting, at least to me, the why of why were things designed the way they were. That is why I started this thread. To satisfy the curiosity of those of us who don't know or think we may know but aren't sure and provoke interesting conversation and debate among those of you more knowledgeable.
It's also just a coincidence my two original and this pick involve range. Could be any feature, good or bad and I would truly love to here some others ideas or questions of why things were thhe way they were. That's one of thee things that make this all interesting. At least in my opinion.


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## michael rauls (Jul 22, 2018)

Hey look everyone, paragraphs. I found the enter button at last .


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## Shortround6 (Jul 22, 2018)

michael rauls said:


> No not nescesarily. Just a curiosity hence the question. I guess the answer in the case of the p47 is more that the need for more range sprang up later and wasn't know at the time of development as opposed to the bf109 and spitfire which were a combination of this and space, wieght limitations, and possibly cog/stability issues with a larger tank if I understood everyones responses corectly.
> That's what's interesting, at least to me, the why of why were things designed the way they were. That is why I started this thread. To satisfy the curiosity of those of us who don't know or think we may know but aren't sure and provoke interesting conversation and debate among those of you more knowledgeable.
> It's also just a coincidence my two original and this pick involve range. Could be any feature, good or bad and I would truly love to here some others ideas or questions of why things were thhe way they were. That's one of thee things that make this all interesting. At least in my opinion.



I also like finding out why things were done the way there were done.
Fighter aircraft, especially in the late 1930s were pretty tight aircraft in the design sense. There is not a lot of extra weight to fool around with even if there was extra volume in the fuselage. You have to have the center of gravity right. To get good speed and climb you have to keep the payload small. 

A really good designer ties to anticipate future needs/growth rather than make a plane too tight but their crystal balls only work so well. 
Somebody was smart enough on the Spitfire to put ballast weights in or on the engine mounts of the planes with the two blade wooden propellers so when they were changed to to the variable pitch props the weights could be removed and the plane's CG stayed pretty much the same,. One reason for NOT sticking fuel tank/s behind the seat on the early planes. 
By the time you get to the MK IX with the two stage Merlin the Spitfire was carrying five 17.5lb weights in the tail to help balance the heavier engine and prop, this is addition to the bigger radiators/intercoolers being mounted just behind the CG.
Of course this means the MK IX was carrying 87.5 lb of pig iron that did nothing for strength or endurance or firepower or............. 

Other planes did some similar things. Bf 109s with wooden tail components got thicker oil cooler armor to help keep them in balance. 

We can sit at our computers/smartphones and talk about adding this or subtracting that but it was often a lot harder in real life if you want the plane to fly safely.

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## michael rauls (Jul 22, 2018)

Shortround6 said:


> I also like finding out why things were done the way there were done.
> Fighter aircraft, especially in the late 1930s were pretty tight aircraft in the design sense. There is not a lot of extra weight to fool around with even if there was extra volume in the fuselage. You have to have the center of gravity right. To get good speed and climb you have to keep the payload small.
> 
> A really good designer ties to anticipate future needs/growth rather than make a plane too tight but their crystal balls only work so well.
> ...



All truly fascinating info.
With reference to your last paragraph, I know many things are easier said than done and didn't mean this thread so much to be a criticism of designers for lack of foresight but more of a honest discussion of why things were the way they were.


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## pbehn (Jul 22, 2018)

michael rauls said:


> No not nescesarily. Just a curiosity hence the question. I guess the answer in the case of the p47 is more that the need for more range sprang up later and wasn't know at the time of development as opposed to the bf109 and spitfire which were a combination of this and space, wieght limitations, and possibly cog/stability issues with a larger tank if I understood everyones responses corectly.
> That's what's interesting, at least to me, the why of why were things designed the way they were. That is why I started this thread. To satisfy the curiosity of those of us who don't know or think we may know but aren't sure and provoke interesting conversation and debate among those of you more knowledgeable.
> It's also just a coincidence my two original and this pick involve range. Could be any feature, good or bad and I would truly love to here some others ideas or questions of why things were thhe way they were. That's one of thee things that make this all interesting. At least in my opinion.


There was an astonishing number of people who held beliefs that defied all the evidence before them. Someone said "The more enemy fighters are sent up the more we will shoot down" or similar and he was talking about the Wellington. Despite the Germans and British switching to night time bombing even in 1942 to early 43 the suggestion that the B17 couldn't get through was considered heresy to some. Escorting US bombers was not considered to be possible or actually needed until it was demonstrated to be.

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## pbehn (Jul 22, 2018)

With retracting undercarriage you need somewhere for the wheels to retract into and a hydraulic or pneumatic system to power the system. The first Spitfires used a manually pumped system. system

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## Shortround6 (Jul 22, 2018)

michael rauls said:


> All truly fascinating info.
> With reference to your last paragraph, I know many things are easier said than done and didn't mean this thread so much to be a criticism of designers for lack of foresight but more of a honest discussion of why things were the way they were.




It is a very complicated subject. Sometimes politics and military considerations play into things as well as just the technical designs. 
Picking on the RAF again (simply because I am lazy and have the figures at hand) they went from 12 fighter squadrons at home (British Isles) in 1925 down to 10 in 1930 and up to 14 in 1935 and then to about 54 in Jan 1940 (British Isles and France).
This vast expansion needed some sort of planes and waiting for the latest and greatest might very well mean* no new planes *(or very few) had fighting broke out in 1938 or very early 1939. 
Again sticking with the British the Merlin I,II, III, X was available but the only other engines that were available in quantity were the Bristol Mercury and Pegasus. 
The Perseus was by the handful and the Hercules was still experimental (ditto for Taurus) as were the Vulture and Sabre. less said about the A-S Tiger the better. 
Without buying engines from abroad (unthinkable until about 1938) the designers, even without air ministry interference were in something of a bind. There were a lot of designs in 1937-38-39 for the "new" engines but most were placed on hold or canceled as the new engines proved a lot harder to sort out than thought. 
Not to pick on the British, the Wright R-3350 was placed on hold about this time and essentially started over again with a fresh sheet of paper before it made it into the B-29 and even then things were not as desired. The continental XIV-1430 has already been mentioned. 

We also have to be careful when reading some of the old requirements not to look at them with modern eyes. Like the specification for the fixed landing gear Supermarine 224. It called for a day and NIGHT fighter. This was Westlands entry into the same competition. 





They really took the part about good view from the cockpit to heart and foreshadowing the P-39 got the exhaust well out of the pilots view for night fighting.
Off course with top speed of about 185mph it's chances of catching any sort of monoplane bomber were about nil. 
Night fighting at the time had nothing to do with radar or any other sensor except the MK I eyeball. It had to do with being able to take-off, fly around for a while and land on the ground without crashing into anything.

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## michael rauls (Jul 22, 2018)

Shortround6 said:


> It is a very complicated subject. Sometimes politics and military considerations play into things as well as just the technical designs.
> Picking on the RAF again (simply because I am lazy and have the figures at hand) they went from 12 fighter squadrons at home (British Isles) in 1925 down to 10 in 1930 and up to 14 in 1935 and then to about 54 in Jan 1940 (British Isles and France).
> This vast expansion needed some sort of planes and waiting for the latest and greatest might very well mean* no new planes *(or very few) had fighting broke out in 1938 or very early 1939.
> Again sticking with the British the Merlin I,II, III, X was available but the only other engines that were available in quantity were the Bristol Mercury and Pegasus.
> ...



Yes it does seem to be a complicated subject. One of the reasons it's so fascinating. At least to me.
One of the general themes that seems to be emerging here, at least as it pertains to design features that may look questionable with the benefit of hindsight years later, is the constant oposing dynamics of wanting the best performance posible but needing something at least utilitarian right now/soon and in needed quantity. 
As a Soviet general once said( can't remember the name right now just the quote)" quantity has a quality all its own"


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## pbehn (Jul 22, 2018)

michael rauls said:


> Yes it does seem to be a complicated subject. One of the reasons it's so fascinating. At least to me.
> One of the general themes that seems to be emerging here, at least as it pertains to design features that may look questionable with the benefit of hindsight years later, is the constant oposing dynamics of wanting the best performance posible but needing something at least utilitarian right now/soon and in needed quantity.
> As a Soviet general once said( can't remember the name right now just the quote)" quantity has a quality all its own"


The answer to most things is "it's complicated"...….. I found out reading stuff here. In general the more power you have the more you can do. Planes like the P-47 and Typhoon had the power and weight of what were considered medium bombers just a few years before like the Do-17. The Bf 109 was so small it was restricting to tall and broad pilots while P-47 pilots joked that they could take evasive action by running around the cockpit.

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## fastmongrel (Jul 22, 2018)

MiTasol said:


> contained more money for hay for horses than fuel for vehicles, tanks, etc.



Which is very odd seeing as the British Army had sold all it's draught horses in 1937 and most of it's Cavalry horses apart from ceremonial mounts went in 1938. The main buyer of ex Army horse's was a little known Army called the German Army.

The Indian Army still had draught and Cavalry horses in 1939.


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## pbehn (Jul 22, 2018)

The common use of Barbed wire thought Europe meant that horses were of little use.


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## KiwiBiggles (Jul 22, 2018)

fastmongrel said:


> Which is very odd seeing as the British Army had sold all it's draught horses in 1937 and most of it's Cavalry horses apart from ceremonial mounts went in 1938. The main buyer of ex Army horse's was a little known Army called the German Army.
> 
> The Indian Army still had draught and Cavalry horses in 1939.


Some people just have a real problem thinking of the UK as an industrial powerhouse, with the most completely-mechanized army in the world, and the world's biggest aircraft industry. There is a lingering perception of Britain as a bucolic idyll, populated by Colonel Blimp types and muddling by on machines built of canvas and straw.

I note that the only reference for his assertion is "I think I read in a book once".


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## pbehn (Jul 22, 2018)

KiwiBiggles said:


> Some people just have a real problem thinking of the UK as an industrial powerhouse, with the most completely-mechanized army in the world, and the world's biggest aircraft industry. There is a lingering perception of Britain as a bucolic idyll, populated by Colonel Blimp types and muddling by on machines built of canvas and straw.
> 
> I note that the only reference for his assertion is "I think I read in a book once".


There were 113,000 universal carriers produced, how many have been seen in a WW2 movie? 26,00 Lloyd carriers too. There were 3 time as many Jeeps produced but 100 times more appeared in movies.


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## Shortround6 (Jul 22, 2018)

pbehn said:


> The common use of Barbed wire thought Europe meant that horses were of little use.


Horses may have been of little use in a cross country cavalry charge but EVERY European power except England relied on horses for the movement of goods on public roads and their armies relied on them for the movement of guns and supplies whenever and wherever the railroads could not be relied on or were overloaded.


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## pbehn (Jul 22, 2018)

Shortround6 said:


> Horses may have been of little use in a cross country cavalry charge but EVERY European power except England relied on horses for the movement of goods on public roads and their armies relied on them for the movement of guns and supplies whenever and wherever the railroads could not be relied on or were overloaded.


Yes but only on clear road and highways, theoretically a horse can go anywhere, but by 1939 they were restricted to the roads.


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## Shortround6 (Jul 22, 2018)

pbehn said:


> There were 113,000 universal carriers produced, how many have been seen in a WW2 movie? 26,00 Lloyd carriers too. There were 3 time as many Jeeps produced but 100 times more appeared in movies.




The British army was fully motorised before the war. That is motorised and not mechanized. 
2 things. 
1 Mechanized means tracks, motorised means wheeled vehicles. 
2. fully motorised does not mean everybody had a ride. Infantry walked/marched but all supplies, artillery and support equipment had wheeled vehicles with a smattering of tracked thrown in. It means horses were no longer used as prime movers.

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## Shortround6 (Jul 22, 2018)

pbehn said:


> Yes but only on clear road and highways, theoretically a horse can go anywhere, but by 1939 they were restricted to the roads.


 The bulk of the German army that attacked Poland and later France was horse drawn. Much of the Italian Army was horse drawn, not the part that went to Africa. 
Few of those horse drawn wagons or larger artillery pieces were going very far off road with horse traction even if there was no barbed wire or fences. 
A large part of the French army was horse drawn.


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## pbehn (Jul 22, 2018)

Shortround6 said:


> The bulk of the German army that attacked Poland and later France was horse drawn. Much of the Italian Army was horse drawn, not the part that went to Africa.
> Few of those horse drawn wagons or larger artillery pieces were going very far off road with horse traction even if there was no barbed wire or fences.
> A large part of the French army was horse drawn.


I was mainly discussing scouting and civilian movement, not even exclusively by horse. Fencing off of fields meant that roads had to be used.


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## Just Schmidt (Jul 23, 2018)

Ok, I'll bite, and it's not about horse power, but the usual suspects.

Meaning the bf 109 and the Spitfire, though as both were among the few making it all through the war, it's hardly surprising they get discussed a lot. And though their late war merits can be debated (that at least should be evidenced by countless threads), looking at the time before the appearance of the Fw 190 they tower above practically everything else (a not altogether unproblematic statement, but at least in raw performance they seem to have no early equal. Thus, as an aside, I do believe the Spitfire mk I to have a good speed for the power available). But in comparing the two, it is interesting to note some rare features they had in common, but that few later found it worth copying.

What i am thinking about in this context is the arrangement of radiators under the wings. To be sure Messerschmitt used it on the 110 and on later designs, but apart from those, from what I can recall right now, only the Re 2001 had a similar arrangement, though I look forward to get a listing of the several designs I'm certain I'm overlooking here, preferably with pictures, thanks in advance. However, this common feature of two top fighters never became anything near standard throughout the world of fighter aircraft, and i would be very interested in hearing the rest of the forums opinions on the pros and cons of this arrangement?

Should anybody think that's not enough on their plate, i can throw in the annular radiators known from a few allied, but many German designs, the Ju 88 family, He 219 and Fw 190D springs to mind. In some previous thread the arrangement was deemed not very efficient in cooling for the price paid in drag, and I'm wondering if it was mostly the ease of interchangability between radials and in-line on the same basic airframe, and that it was the easiest way to find/make room for it?

I'm looking forward to yet another round of messerspit bashing...

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## fastmongrel (Jul 23, 2018)

The Royal Army Service Corps the logistics organization for the army had got rid of it's horses by 1930. By 1934 the Engineers and Signals were fully motorised. The Artillery in 1934 was mostly motorised apart from a small number of mountain howitzer batteries and Territorial 18pounder batteries. Experments were carried out throughout the 30s with motorised infantry the Durham Light Infantry being the cheif guinea pigs, these experiments led to the new 1937 pattern Battle Dress and webbing system which allowed men to sit more comfortably and not get hung on their equipment when entering or leaving a vehicle.


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## pbehn (Jul 23, 2018)

Need I point out that the UK is an Island group, getting horses anywhere even across the channel is a nightmare.


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## wuzak (Jul 23, 2018)

Just Schmidt said:


> Ok, I'll bite, and it's not about horse power, but the usual suspects.
> 
> Meaning the bf 109 and the Spitfire, though as both were among the few making it all through the war, it's hardly surprising they get discussed a lot. And though their late war merits can be debated (that at least should be evidenced by countless threads), looking at the time before the appearance of the Fw 190 they tower above practically everything else (a not altogether unproblematic statement, but at least in raw performance they seem to have no early equal. Thus, as an aside, I do believe the Spitfire mk I to have a good speed for the power available). But in comparing the two, it is interesting to note some rare features they had in common, but that few later found it worth copying.
> 
> ...



The Spiteful had a radiator layout similar to the 109's - shallow profile, but wide, and on the trailing edge of the wing.

The Spitfire's radiator problems revolved around the area of the inlet and outlet compared with each other and the radiator matrix, and the outlet flap, which was used to control the air flow through the radiator, having only 2 positions (at least on early versions).

Napier experimented with an annular radiator for the Sabre late in the war and the immediate post war. It was more sophisticated than the ones used by the Germans, I believe.

The Merlin XX power egg was designed to replace the Hercules on the Beaufighter. It contained the radiator, and oil coolers (?), so it was a direct swap. 

If you ever see the pictures of the XB-38 (V-1710 powered B-17) without its cowling, you can see how much room a liquid cooled V12 has when fitted to a nacelle designed for a radial. It had space for all the coolers, but strangely they only used it for the intercooler (despite the B-17 already having an intercooler in the nacelle) and used the leading edge between the engines on the wing for the radiators.

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## pbehn (Jul 23, 2018)

wuzak said:


> The Merlin XX power egg was designed to replace the Hercules on the Beaufighter. It contained the radiator, and oil coolers (?), so it was a direct swap.
> .


I thought the power egg idea was strategic, in case an engine manufacturer was hit?


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## swampyankee (Jul 23, 2018)

E


pbehn said:


> I was mainly discussing scouting and civilian movement, not even exclusively by horse. Fencing off of fields meant that roads had to be used.


Even if the fields weren’t fenced, roads are preferred: they were likely to require less energy, especially to pull a wagon, and the crops in a field would get damaged.


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## Shortround6 (Jul 23, 2018)

swampyankee said:


> E
> 
> Even if the fields weren’t fenced, roads are preferred: they were likely to require less energy, especially to pull a wagon, and the crops in a field would get damaged.


 I would note in addition that the roads were usually hard packed or gravel and while a good rain might make a mess of them you are going to get more horse drawn wagons over a road, in part due to the lower rolling resistance/less energy in a period of time than field or meadow that is going to rut very quickly.
There is a reason they built roads from roman times on, if not before.


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## wuzak (Jul 23, 2018)

pbehn said:


> I thought the power egg idea was strategic, in case an engine manufacturer was hit?



Yes, but more with the delays with Hercules production, and the fear there would not be enough to go around.

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## yulzari (Jul 24, 2018)

The British Army was acutely aware that half of WW1 shipping across the Channel was forage for horses. Not to mention oceanic shipping bringing in horses from as far away as Argentina and Australia. With all the other things to be manufactured in WW2 it was Canadian lorries that kept the British army mechanised. Thank you Canada. 

BTW when my father joined the Royal Signals in the mid 1930's they were still using horse drawn wagons for line laying and the GS wagon was still being used for assorted minor tasks.

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## MiTasol (Jul 24, 2018)

KiwiBiggles said:


> I note that the only reference for his assertion is "I think I read in a book once".



I have just purchased the replacement book I have been looking for. I had been searching for _Guns of the RAF_ when I should have been searching for _Guns of the Royal Air Force _by GF Wallace - the book description is Hardcover Publisher: William Kimber and Co. Limited., London, 1972 Used - Fine. Size: Medium 8vo. 221pp.; includes dustjacket (AVIATION. MILITARY HISTORY. SECOND WORLD WAR. RAF.)

With luck it will reach Australia within 2 or 4 days (the usual from the USA). After that tracking will become meaningless until it is delivered. My last book from the same vendor took 12 days after clearing customs in Sydney giving it an average travel speed of under 150 km (100 miles) per day, pretty fast for non-CBD mail in Australia.


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## David Fred (Jul 27, 2018)

michael rauls said:


> I would verry much like to hear everyones thoughts on design on issues pertaining to a particular plane that kept ok planes from being good, good planes from being great, and great planes from being darn near perfect( or at least as close to it as could be humanly expected at the time of its design). The obvious picks for me are two great planes that could have been darn near perfect , the Bf109 and the spitfire, both for the same two issues. Those being the narrow undercarriage and limited fuel capacity. I'm sure there are many examples so " why the heck did they design it that way"


The undercarriage bit, especially, and on the Spitfire, especially. With that thin wing, you would have thought you’d want the fat wheel inboard, on the thickest part of the wing.

Fuel capacity.
Well, we know the Spitfire was designed as a point interceptor, a defensive fighter, so less range, less fuel, less weight, more speed, better rate of climb, etc.
And both were tactical, rather than Strategic weapons. The bomber would always get through (Sir Hugh Trenchard) so no need for escort fighters. Just need masses of short range fighters to shoot down as many bombers as possible of the enemies. 
That conflict in thinking has always bothered me.
MY bombers will always get through, so I need no escorts, but I can build fighters so the enemy CAN’T get through with HIS bombers.
Germany too thought of their aircraft TACTICALLY, to safeguard short range medium bombers, with a forward placement of shorter ranged fighters.
I agree, a conundrum m.

Dave

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## David Fred (Jul 27, 2018)

michael rauls said:


> I would verry much like to hear everyones thoughts on design on issues pertaining to a particular plane that kept ok planes from being good, good planes from being great, and great planes from being darn near perfect( or at least as close to it as could be humanly expected at the time of its design). The obvious picks for me are two great planes that could have been darn near perfect , the Bf109 and the spitfire, both for the same two issues. Those being the narrow undercarriage and limited fuel capacity. I'm sure there are many examples so " why the heck did they design it that way"




There is a good book on British thinking in WW2 and just prior.
Attached image. There are lots of used copies on Amazon. That’s where I got mine.

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## michael rauls (Jul 27, 2018)

David Fred said:


> The undercarriage bit, especially, and on the Spitfire, especially. With that thin wing, you would have thought you’d want the fat wheel inboard, on the thickest part of the wing.
> 
> Fuel capacity.
> Well, we know the Spitfire was designed as a point interceptor, a defensive fighter, so less range, less fuel, less weight, more speed, better rate of climb, etc.
> ...


 I never thought of that contradiction in thinking you so aptly point out. Ya if the bomber will always get through then whats with all the interceptors.


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## michael rauls (Jul 27, 2018)

David Fred said:


> View attachment 503592
> 
> 
> 
> ...


 And thanks for the heads up on the book. Looks good and like it might answer quite a few other questions I have about early war and pre war thinking. Several people here have given me some really goog book suggestions. Just got my first delivery of 3 of those yesterday as a matter of fact.


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## Shortround6 (Jul 27, 2018)

There was a lot of contradictory thinking going on. 

Like,

Lets use a fixed pitch prop on the interceptors so that will save around 200-250lbs on a 5500lb airplane and give us better climb..........

Of course because the pitch on a fixed pitch prop suitable for 350mph is so extreme it means we have to throttle our 3000rpm engine down to no more than 2200rpm (less?) for take-off and limit it to somewhere between 2200rpm and 2400rpm (depending on altitude) when climbing instead of the 2600rpm the engine is rated for max continuous (or at least 1/2 hour) but hey, the lighter weight will make up for the loss in power, right??????????

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## michael rauls (Jul 27, 2018)

Shortround6 said:


> There was a lot of contradictory thinking going on.
> 
> Like,
> 
> ...


 Maybe it's just because we have the benefit of hindsight but some of that stuff really does make one wonder about the thought process. 
Apparent foot dragging on the deployment of the Me262 is another one that has always puzzled me.


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## buffnut453 (Jul 27, 2018)

David Fred said:


> The undercarriage bit, especially, and on the Spitfire, especially. With that thin wing, you would have thought you’d want the fat wheel inboard, on the thickest part of the wing.



The problem is that placing an undercarriage further from the fuselage demands wing spars that are capable of withstanding all the forces and moments associated with the landing impact. That requires a heavier structure but that, surprise surprise, will further increase landing forces. Now, it's clearly not an endless spiral but Mitchell clearly thought it better to have the narrow track Spitfire undercarriage with its skinny tyres rather than a Hurricane-like inward-retracting design that would have required more airframe weight just to make it feasible.





David Fred said:


> Well, we know the Spitfire was designed as a point interceptor, a defensive fighter, so less range, less fuel, less weight, more speed, better rate of climb, etc.
> And both were tactical, rather than Strategic weapons. The bomber would always get through (Sir Hugh Trenchard) so no need for escort fighters. Just need masses of short range fighters to shoot down as many bombers as possible of the enemies.
> That conflict in thinking has always bothered me.
> MY bombers will always get through, so I need no escorts, but I can build fighters so the enemy CAN’T get through with HIS bombers.
> ...



Well...yes and no. Bear in mind that fighters were rather neglected between the wars in most air forces. For example, many USAAC officers who were advocates of "pursuit" aircraft felt that their careers were being hindered by the "bomber barons" who refused to invest in fighter development. This is precisely the reason cited for Chennault's resignation (and we know where that ended up). 

From the RAF perspective, there were additional factors which might have pushed senior leaders further into what might be seen as a paradoxical position. For starters, RAF heavy bombers were increasingly armed with power turrets which were seen as more effective than other defensive weapon systems. Then there's the development of radar and an integrated air defence system throughout the 1930s which offered the possibility of more effective use of available fighters. We should not forget that the RAF still had a large number of biplane fighters in front-line service in September 1939 which just shows that the rapid rearmament with modern fighters, which only started with the order of the Hurricane in 1936, didn't come a moment too soon. ​

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## michael rauls (Jul 27, 2018)

Another good why the heck did they design it that way is the Boulton Paul Defiant with no forward facing armament at all. Not that the adition of such would have made it a great plane but maybe at least a ok one although I read they did ultimately find some use intercepting German bombers at night.


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## FLYBOYJ (Jul 27, 2018)

michael rauls said:


> Another good why the heck did they design it that way is the Boulton Paul Defiant with no forward facing armament at all. Not that the adition of such would have made it a great plane but maybe at least a ok one although I read they did ultimately find some use intercepting German bombers at night.


The Defiant was developed per an RAF specification, F.9/35 which called out the turret armament. The manufacturer built what the customer requested.


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## GrauGeist (Jul 27, 2018)

michael rauls said:


> Another good why the heck did they design it that way is the Boulton Paul Defiant with no forward facing armament at all. Not that the adition of such would have made it a great plane but maybe at least a ok one although I read they did ultimately find some use intercepting German bombers at night.


The turret could rotate and lock forward with the MGs depressed to a max of about 18 degrees elevation, with the pilot having fire control.

It was not designed as a fighter, it was purely a bomber interceptor with the idea of flying in groups to intercept bomber formations and exchanging fire like in the days of sail, where the ships exchanged broadsides.

Keep in mind that the U.S. Navy had similar aircraft in service, though not fighters, they still had turrets on a single-engine airframe.

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## michael rauls (Jul 27, 2018)

FLYBOYJ said:


> The Defiant was developed per an RAF specification, F.9/35 which called out the turret armament. The manufacturer built what the customer requested.


 Then I guess in all fairness the focus of my bewilderment should be whoever issued RAF specification F.9/35 and not the Boulton Paul Aircraft Company. Maybe it was one of those ideas that looked good on paper but in practice didn't fair so well.


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## michael rauls (Jul 28, 2018)

GrauGeist said:


> The turret could rotate and lock forward with the MGs depressed to a max of about 18 degrees elevation, with the pilot having fire control.
> 
> It was not designed as a fighter, it was purely a bomber interceptor with the idea of flying in groups to intercept bomber formations and exchanging fire like in the days of sail, where the ships exchanged broadsides.
> 
> Keep in mind that the U.S. Navy had similar aircraft in service, though not fighters, they still had turrets on a single-engine airframe.


 Now there's some new information. I'm sure i have read specifically that the Defiants could not be made to fire forward. 
I'm sure your correct though. I'm learning alot of the things claimed in alot of books and websites can be a bit dodgy so to speak. Funny, all these years I've wondered about this obvious oversight and turns out it wasn't the case at all.


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## Greyman (Jul 28, 2018)

I gotta say, "the bomber will always get through" has to be one of the most misunderstood quotations.

The idea wasn't that bombers would always get through to their targets no matter what the enemy did to defend - it was that no matter how much effort you put into defense, your cities wouldn't escape being bombed.


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## MiTasol (Jul 28, 2018)

michael rauls said:


> Now there's some new information. I'm sure i have read specifically that the Defiants could not be made to fire forward.
> I'm sure your correct though. I'm learning alot of the things claimed in a lot of books and websites can be a bit dodgy so to speak. Funny, all these years I've wondered about this obvious oversight and turns out it wasn't the case at all.



Don't we all know it - how many times a month does someone state that some (or all) Allison powered aircraft did not have superchargers. 

The B-P Defiant's pilots notes are at Boulton-Paul Defiant Pilots Notes The diagram on page 18 has the pilots gun firing button on the control grip.

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## Greyman (Jul 28, 2018)

Recent thread: Boulton Paul Defiant Rationale

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## michael rauls (Jul 28, 2018)

MiTasol said:


> Don't we all know it - how many times a month does someone state that some (or all) Allison powered aircraft did not have superchargers.
> 
> The B-P Defiant's pilots notes are at Boulton-Paul Defiant Pilots Notes The diagram on page 18 has the pilots gun firing button on the control grip.


 Just viewed that link you posted. Now that is interesting ! Thank you.


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## Ascent (Jul 28, 2018)

I don't think that 'the bomber will always get through' was particularly ridiculous until the advent of radar. Until then you had to have standing patrols and you couldn't vector fighters to the target until they were much too close.

Once radar and the control network come in all bets are off. Where forces went wrong is persisting with the belief after it was shown what radar could do for the defender.

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## michael rauls (Jul 28, 2018)

Ascent said:


> I don't think that 'the bomber will always get through' was particularly ridiculous until the advent of radar. Until then you had to have standing patrols and you couldn't vector fighters to the target until they were much too close.
> 
> Once radar and the control network come in all bets are off. Where forces went wrong is persisting with the belief after it was shown what radar could do for the defender.


 Good point.


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## pbehn (Jul 28, 2018)

David Fred said:


> MY bombers will always get through, so I need no escorts, but I can build fighters so the enemy CAN’T get through with HIS bombers.
> Germany too thought of their aircraft TACTICALLY, to safeguard short range medium bombers, with a forward placement of shorter ranged fighters.
> I agree, a conundrum m.


Without RADAR things would be radically different. The Chain Home system was about as primitive as it is possible to be and still work adequately. From initial work in 1935 on just seeing if it was possible the CH system (with Chain home low) was just being completed in 1940. Anyones opinion before 1935 or before 1940 who wasn't aware of RADAR was speaking from ignorance. Without RADAR fighters of WW2 would have to mount standing patrols, this is a huge effort with no guarantee of results.

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## fastmongrel (Jul 28, 2018)

michael rauls said:


> And thanks for the heads up on the book. Looks good and like it might answer quite a few other questions I have about early war and pre war thinking. Several people here have given me some really goog book suggestions. Just got my first delivery of 3 of those yesterday as a matter of fact.



It's an interesting read but some of it's main points are outdated. Especially on tactics and armament. Particularly the section on armament, I hate to say it but the section about .50 heavy machine guns is absolute rubbish falling into the usual trap of using the performance of a late war Browning M2 and it's ammo when a 1939 M2 and it's ammo were a completely different beast.


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## Shortround6 (Jul 28, 2018)

Greyman said:


> I gotta say, "the bomber will always get through" has to be one of the most misunderstood quotations.
> 
> The idea wasn't that bombers would always get through to their targets no matter what the enemy did to defend - it was that no matter how much effort you put into defense, your cities wouldn't escape being bombed.



This is right.
Another thing the rapidly changing progress that was being made that had first one side and then the other appear dominate. Most Biplanes were limited by their engine power between 1 and 2 hours of endurance so standing patrols were difficult and wasteful. Few 1920s fighters or early 30s fighters even had radios so vectoring in planes under ground control wasn't going to work even using observers on the ground without radar. 
With limited engine power adding a 3rd and 4th machine gun did impact performance significantly. The Bristol Bulldog for example first flew in 1927 and in it's later form only had 440hp, this was the version that made up over 1/2 of the British fighter defense in Jan 1935. 
The later Hawker Fury had 640hp and while speed had increase to a peak of 223mph endurance had not changed much. 

A lot of store was placed in the maneuverability of fighters which made air forces (and designers/manufacturers) reluctant to change to monoplanes. A biplane will be lighter for the same square footage of wing area than a monoplane due the brace effect of the two wings and the struts. 
With less expectations of maneuverability it was easier for some countries (builders) to switch to monoplane bombers in a quest for higher speed to avoid interception (and get longer range).
In Spain even relatively crude monoplanes with retractable landing gear flew fast enough to make interception difficult for the mostly biplane intercepters in the beginning. 
With defensive guns on bombers limited to 1 or 2 hand aimed rcmgs per mount they bombers had little advantage in defensive armament if any over the twin guns that were almost standard on fighters.
With the coming of powered gun mounts and much improved ability to aim (sometimes figured at around 3 times more effective than hand aimed) and long belt feeds vs 75-100 round magazines (and faster firing guns) the defensive ability of _some_ bombers took a big leap, unfortunately at the same time the fighters went from bipanes to monoplanes and went to at least 4 machine guns or a cannon/machine gun combination. 

Since not all countries made these changes at the same time it took quite a while for changes in tactics or equipment to really show their effects.

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## michael rauls (Jul 28, 2018)

fastmongrel said:


> It's an interesting read but some of it's main points are outdated. Especially on tactics and armament. Particularly the section on armament, I hate to say it but the section about .50 heavy machine guns is absolute rubbish falling into the usual trap of using the performance of a late war Browning M2 and it's ammo when a 1939 M2 and it's ammo were a completely different beast.


 10-4. Sounds like like it might be useful for understanding the mindset at the time though especially as it relates to some design and tactical decisions that might seem questionable now.

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## pbehn (Jul 28, 2018)

Also, we look at things with hindsight, if Leigh Mallory was in charge during the BoB and someone like Park in charge of the LW the bomber would probably have got through and the USAAF not given the chance in Europe.


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## Greyman (Jul 28, 2018)

_"The Wehrmacht channel barge will always get through."_

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## pbehn (Jul 28, 2018)

Greyman said:


> _"The Wehrmacht channel barge will always get through."_


If the RAF were forced back behind London a negotiated peace is not impossible to imagine, some wanted it anyway before the BoB started.

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## fastmongrel (Jul 28, 2018)

michael rauls said:


> 10-4. Sounds like like it might be useful for understanding the mindset at the time though especially as it relates to some design and tactical decisions that might seem questionable now.



Like all history books you need to read it and balance its conclusions with the knowledge that we have more facts to hand than the author because of things like the internet and the release of documents under the 30 years rule. Unfortunately a lot of Air Ministry paperwork was destroyed when the Air Ministry was merged into the Ministry of Defence in 1964. 

Some years ago I tried to research the history of a relative who served as a pilot in the RAF 1940 to 1943 I discovered where he is buried and that he had been awarded the Air Force Cross but the reasons for his death and why he was awarded the AFC were not available, I was told that in 1964 lorry loads of records were sent out to be buried under an extension to the north London Circular road.

Fying Officer Wilfred Seaman AFC


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## michael rauls (Jul 28, 2018)

fastmongrel said:


> Like all history books you need to read it and balance its conclusions with the knowledge that we have more facts to hand than the author because of things like the internet and the release of documents under the 30 years rule. Unfortunately a lot of Air Ministry paperwork was destroyed when the Air Ministry was merged into the Ministry of Defence in 1964.
> 
> Some years ago I tried to research the history of a relative who served as a pilot in the RAF 1940 to 1943 I discovered where he is buried and that he had been awarded the Air Force Cross but the reasons for his death and why he was awarded the AFC were not available, I was told that in 1964 lorry loads of records were sent out to be buried under an extension to the north London Circular road.
> 
> Fying Officer Wilfred Seaman AFC


 Good point about older history books and that we have alot more information available now the trouble is, with so much apparently erroneous information out there especially on the internet, to be honest not being exactly an expert myself often I have a hard time discerning whats accurate and what's not.
About your relative, do you know what kind of aircraft he flew? Just curious. 
Also I think it's a shame so few seemed even years later to recognise how valuable those records as well as the aircraft themselves were and would become and didn't do a better job of preservation.


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## GrauGeist (Jul 28, 2018)

michael rauls said:


> Also I think it's a shame so few seemed even years later to recognise how valuable those records as well as the aircraft themselves were and would become and didn't do a better job of preservation.


For many, WWII was a horrible memory that couldn't be done away with soon enough.

For others, those countless lines of parked aircraft or AFVs meant a great deal of money to be had in recycling and for Governments, they were an accounting and logistics nightmare - the sooner they were gone, the better.

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## pbehn (Jul 28, 2018)

michael rauls said:


> Good point about older history books and that we have alot more information available now the trouble is, with so much apparently erroneous information out there especially on the internet, to be honest not being exactly an expert myself often I have a hard time discerning whats accurate and what's not.
> About your relative, do you know what kind of aircraft he flew? Just curious.
> Also I think it's a shame so few seemed even years later to recognise how valuable those records as well as the aircraft themselves were and would become and didn't do a better job of preservation.


Even "Churchills History of WW2" was not completely comprehensive there were things that couldn't be included because of the 30 yr rule even though Churchill obviously was aware of them.


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## swampyankee (Jul 28, 2018)

michael rauls said:


> Good point about older history books and that we have alot more information available now the trouble is, with so much apparently erroneous information out there especially on the internet, to be honest not being exactly an expert myself often I have a hard time discerning whats accurate and what's not.
> About your relative, do you know what kind of aircraft he flew? Just curious.
> Also I think it's a shame so few seemed even years later to recognise how valuable those records as well as the aircraft themselves were and would become and didn't do a better job of preservation.



Losing the records is, in my opinion, generally far, far worse than losing the hardware.

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## michael rauls (Jul 28, 2018)

GrauGeist said:


> For many, WWII was a horrible memory that couldn't be done away with soon enough.
> 
> For others, those countless lines of parked aircraft or AFVs meant a great deal of money to be had in recycling and for Governments, they were an accounting and logistics nightmare - the sooner they were gone, the better.


 I can see how to many WW2 was a just bad memory they would like to forget. That makes sense. It just seems to me because of the monumental importance of what had just transpired and out of reverence for the men and women who risked and in many cases lost there lives the value of preservation would be apparent.
Also I can see how you can't save hundreds of every type forever but when I read stories for example about how after vj day they buldozed p47ns into the Pacific or perhaps later when the last few f6fs were retired from active service. i wonder why someone with the power to do so didn't say" hay wait a minute, maybe we should save a few of those things". Certainly more than the dozen or so airworthey of most types we have left.
I realize hindsight and my personal fascinating with the history, personel, and equipment may be coloring my viewpoint but that's thw way it looks to me.


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## pbehn (Jul 28, 2018)

michael rauls said:


> I can see how to many WW2 was a just bad memory they would like to forget. That makes sense. It just seems to me because of the monumental importance of what had just transpired and out of reverence for the men and women who risked and in many cases lost there lives the value of preservation would be apparent.
> Also I can see how you can't save hundreds of every type forever but when I read stories for example about how after vj day they buldozed p47ns into the Pacific or perhaps later when the last few f6fs were retired from active service. i wonder why someone with the power to do so didn't say" hay wait a minute, maybe we should save a few of those things". Certainly more than the dozen or so airworthey of most types we have left.
> I realize hindsight and my personal fascinating with the history, personel, and equipment may be coloring my viewpoint but that's thw way it looks to me.


Not only post war but later, there isn't even a static display of a dH Hornet while I believe the Mosquito prototype is the only prototype to survive from anywhere

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## michael rauls (Jul 28, 2018)

swampyankee said:


> Losing the records is, in my opinion, generally far, far worse than losing the hardware.


 Good point. Plus I can see how keeping legions of hardware around and functional could be cost and time prohibiting( but not for a few dozen of each type I wouldn't think considering the scale ot the world economy even in 1946 and given the importance) but how much time and effort does it take to keep some warehouses full of records.


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## michael rauls (Jul 28, 2018)

pbehn said:


> Not only post war but later, there isn't even a static display of a dH Hornet while I believe the Mosquito prototype is the only prototype to survive from anywhere


It is truly disturbing that for many types, including some fairly major ones there is not a single whole airframe left in the entire world. I was not aware that no example of the Mosquito other than the prototype existed today. I must say that's a little disappointing to hear.


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## buffnut453 (Jul 28, 2018)

michael rauls said:


> It is truly disturbing that for many types, including some fairly major ones there is not a single whole airframe left in the entire world. I was not aware that no example of the Mosquito other than the prototype existed today. I must say that's a little disappointing to hear.



That's not what the other poster said. There are a number of Mosquitos around the world including at least 2 airworthy examples. The point was that there are no prototypes of any other WW2 aircraft surviving (although you could consider the Horten flying wing at NASM as one example of a surviving prototype).


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## michael rauls (Jul 28, 2018)

buffnut453 said:


> That's not what the other poster said. There are a number of Mosquitos around the world including at least 2 airworthy examples. The point was that there are no prototypes of any other WW2 aircraft surviving (although you could consider the Horten flying wing at NASM as one example of a surviving prototype).


 My bad. I went back and read the post again and yes I misunderstood it the first time. I guess that's slightly less tragic then but there are, at least to the best of my knowledge, many types of which there are1 or 2 or 0 left in the world and thats to bad.

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## pbehn (Jul 28, 2018)

michael rauls said:


> It is truly disturbing that for many types, including some fairly major ones there is not a single whole airframe left in the entire world. I was not aware that no example of the Mosquito other than the prototype existed today. I must say that's a little disappointing to hear.


Well Mosquitos survived post war and there are a couple being restored, many on the ground. You missed my point I think. The prototype Mossie at the De Havilland museum is the only WW2 aircraft prototype of any type to survive to present day. And that is possibly luck, it was used for training.


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## michael rauls (Jul 28, 2018)

pbehn said:


> Well Mosquitos survived post war and there are a couple being restored, many on the ground. You missed my point I think. The prototype Mossie at the De Havilland museum is the only WW2 aircraft prototype of any type to survive to present day. And that is possibly luck, it was used for training.


 Ya sorry i guess i sorta read that part in reverse so to speak.


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## pbehn (Jul 28, 2018)

michael rauls said:


> Ya sorry i guess i sorta read that part in reverse so to speak.


However I must say it was a completely different era, in WW2 from start to finish the RAF introduced more "types" each year than they have in my whole lifetime and I am 58.


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## michael rauls (Jul 28, 2018)

pbehn said:


> However I must say it was a completely different era, in WW2 from start to finish the RAF introduced more "types" each year than they have in my whole lifetime and I am 58.


 True. I guess you can't save enough of every type to equip an airforce but I for one would certainly like to have seen at least a few dozen of each of the major types kept airworthey and perhaps a few dozen more on static display.


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## pbehn (Jul 28, 2018)

michael rauls said:


> True. I guess you can't save enough of every type to equip an airforce but I for one would certainly like to have seen at least a few dozen of each of the major types kept airworthey and perhaps a few dozen more on static display.


As the song says, You don't know what you've got till its gone. I suppose at the time things were moving so quickly they never thought about it. Untill just before WW2 planes were made or mainly organic material, like preserving clothing out in the open air.

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## wuzak (Jul 29, 2018)

pbehn said:


> Well Mosquitos survived post war and there are a couple being restored, many on the ground. You missed my point I think. The prototype Mossie at the De Havilland museum is the only WW2 aircraft prototype of any type to survive to present day. And that is possibly luck, it was used for training.



It was to be sent to the scrap heap a year or two after the war, but was saved by some people with foresight.

Interesting thing about W4050, it doesn't have its original fuselage.

The fuselage was damaged while taxiing during testing, and was replaced by the first production fuselage.

The fuselage also has a patch to cover some other damage.

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## pbehn (Jul 29, 2018)

wuzak said:


> It was to be sent to the scrap heap a year or two after the war, but was saved by some people with foresight.
> 
> Interesting thing about W4050, it doesn't have its original fuselage.
> 
> ...


Like I said its survival was as much down to luck as anything. With other marques it is a mystery how fairly large companies didn't keep any example of their best/most famous products, like the Typhoon the remaining static example is a complete lash up.


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## MiTasol (Jul 30, 2018)

David Fred said:


> View attachment 503592
> 
> There is a good book on British thinking in WW2 and just prior.
> Attached image. There are lots of used copies on Amazon. That’s where I got mine.



Here is another book worth reading. 1940: Myth and Reality. It "rewrites" many of the "official" histories, which were in most cases based on the morale boosting political spin used by the government during the war, by using documents from the Public Records Office. Most of the book is 1940 itself but it covers all the various isssues the government of the time was saddled with starting with the rolling 10 year plan that said the military should be sized and armed on the basis that there would not be a war for the next ten years. That plan was not scrapped until 1934 and the new plan took until 1937 to be agreed on. Chamberlain gets the blame for appeasement but it was driven by the militaries pleas to avoid war at all costs because they were not capable of depending Britain.





Interesting snips include

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## pbehn (Jul 30, 2018)

MiTasol said:


> Here is another book worth reading. 1940: Myth and Reality. It "rewrites" many of the "official" histories, which were in most cases based on the morale boosting political spin used by the government during the war, by using documents from the Public Records Office. Most of the book is 1940 itself but it covers all the various isssues the government of the time was saddled with starting with the rolling 10 year plan that said the military should be sized and armed on the basis that there would not be a war for the next ten years. That plan was not scrapped until 1934 and the new plan took until 1937 to be agreed on. Chamberlain gets the blame for appeasement but it was driven by the militaries pleas to avoid war at all costs because they were not capable of depending Britain.
> 
> View attachment 503733
> 
> ...


I remember reading in a book about the build up to war, on the 3rd September when war was declared a team of German workers were interned in England, they were installing machine tools in Rolls Royce.


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## Shortround6 (Jul 30, 2018)

Getting back to the original premise of the thread, you often have to look at where a design team or airforce was coming from.

Bf 109




2 guns, fixed pitch prop (soon to be replaced) under 700hp engine was replacing 
the HE 51




2 guns, fixed pitch prop, around a 700hp engine (which could be traced back to WW I) and narrow landing gear 
and the Arado 68




2 guns, same basic engine as the early 109. 
They were trying for for a through the prop gun on the early 109s




This plane may have had a machine gun or simply the intention of mounting one, they often malfunctioned and some were removed in service. Not sure if this plane was fitted with wing guns or not, but it does have an adjustable or controllable pitch propeller. 

Narrow landing gear attached to the fuselage was what they were used to. Small fuel tanks giving an endurance of under 2 hours was what they were used to.

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## Timppa (Jul 30, 2018)

michael rauls said:


> Those being the narrow undercarriage and limited fuel capacity. I'm sure there are many examples so " why the heck did they design it that way"



Those are easy...
Why the German V -engines were installed upside down ?


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## BiffF15 (Jul 30, 2018)

Shortround6 said:


> Getting back to the original premise of the thread, you often have to look at where a design team or airforce was coming from.
> 
> Bf 109
> View attachment 503770
> ...




My guess is the 109 groundlooped on takeoff or during a go around. Right main is folded under as if the tail had swung to the right fairly violently. Large p factor not compensated for with rudder? Just a guess based on a single picture.

Also what is the small protuberance with a port in it behind the left main.

While I didn’t sleep in a Holiday Inn Express last night I did attend the USAF Aircraft Mishap Investigator Course at Kirtland AFB many moons ago. 

Cheers,
Biff


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## Reluctant Poster (Jul 30, 2018)

wuzak said:


> Supermarine did try and stuff more fuel into the Spitfire over the years.
> 
> But the amount they could add was limited by the space available in the airframe.
> 
> ...



Not true. The upper tank in a Griffon Spitfire was smaller. The original top tank was 48 imp gallons, the bottom tank was 37 gallons for a total of 85. The Mark VII increased the bottom tank size to 47 for a total of 95. The Griffon was mounted lower than the Merlin (The sighting view over the nose was actually slightly better despite the longer engine), therefore there was no room for the oil tank beneath the nose. The first batch of Mark XIIs were based on the Mark IX airframe and moved the oil tank to the rear fuselage. The last batch were based on the Mark VIII airframe and relocated the oil tank in front of the pilot. To make room the upper tank was reduced to 38 gallons, so the total went back to 85. The Mark XIV retained this arrangement.


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## BiffF15 (Jul 30, 2018)

Timppa said:


> Those are easy...
> Why the German V -engines were installed upside down ?



Timppa,

I’m pretty sure it was for visibility over the nose and for weapons that fired thru the prop hub.

Cheers,
Biff


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## Shortround6 (Jul 30, 2018)

As a wild guess I would say that the protuberance behind the left landing gear might be a gun camera? 
I have no idea if it means anything but the tire on the left landing gear doesn't seem to be on the rim anymore.


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## BiffF15 (Jul 30, 2018)

Shortround6 said:


> As a wild guess I would say that the protuberance behind the left landing gear might be a gun camera?
> I have no idea if it means anything but the tire on the left landing gear doesn't seem to be on the rim anymore.



I thought the same regards possible gun camera. Tire could come off the rim after being deflated due to lateral skidding (have seen the same at car accidents so only a guess).


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## swampyankee (Jul 30, 2018)

Mili


Shortround6 said:


> Getting back to the original premise of the thread, you often have to look at where a design team or airforce was coming from.
> 
> Bf 109
> View attachment 503770
> ...





Timppa said:


> Those are easy...
> Why the German V -engines were installed upside down ?




The official answer is probably something about better pilot visibility.

The _real_ answer is that a general turned the blueprint upside-down and everybody was afraid to correct him.

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## GrauGeist (Jul 30, 2018)

Just for the record: Daimler-Benz, Junkers and Argus weren't the only manufacturers that designed most of their aircraft engines to be inverted.
Ranger Aircraft engines, like the L-440 and V-770 were inverted designs, too.


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## Shortround6 (Jul 30, 2018)

The *real *answer is a German group of visitors to RR in the very early 30s saw a mock up of an inverted engine and promptly went home to copy it

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## Shortround6 (Jul 30, 2018)

GrauGeist said:


> Just for the record: Daimler-Benz, Junkers and Argus weren't the only manufacturers that designed most of their aircraft engines to be inverted.
> Ranger Aircraft engines, like the L-440 and V-770 were inverted designs, too.



So were the British (and Czechoslovakian) in-line 4 and 6 cylinder light aircraft engines but there is another reason coming into play. 

An inverted engine in a light plane can use a larger diameter prop than the same engine in an upright configuration due to the higher thrust line. 
And/or better vision over the nose. Most of the light planes (and even the first Ranger V-12s) didn't use reduction gears so prop was inline with the crankshaft.

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## wuzak (Jul 30, 2018)

As was the de Havilland Gipsy Twelve/Gipsy King.







200-300lbs less weight than a Merlin (without cooling system) as well as 700-800hp less.


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## GrauGeist (Jul 30, 2018)

Ranger's 4 and 6 had the output at the crank, but their 12 did have a reduction gear assembly.

The V-770:


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## Shortround6 (Jul 30, 2018)

Not all of them. They started with a direct drive version 
http://rgl.faa.gov/Regulatory_and_G...171862572c0006f8ec8/$FILE/ATTD3NYA/ATC184.pdf






Please note the early ones were not supercharged either. 

Wiki is wrong, the V-770 was not based on the 6-440.

Fairchild (Ranger) had made 6 cylinder 370, 390 and 410 cu in engines before building the 440. The 770 used the same bore and stoke as the 390 cu in six. 
http://www.enginehistory.org/Piston/Fairchild/Fairchild.shtml


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## tyrodtom (Jul 30, 2018)

I don't know how many people have worked on high performance engines, but a great deal of the work you do on one involves work around the heads,( valve train, spark plugs) 
A inverted engines puts a lot of the work where it can be done from ground level, or from a low platform.
Imagine climbing up and down a ladder, or stepped platform, to perform maintenance task all day, it'd have to wear you down.
I've worked on some big trucks that required working platforms, that sure added to my work load.


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## Timppa (Jul 31, 2018)

tyrodtom said:


> I've worked on some big trucks that required working platforms, that sure added to my work load.



So why are these engines not upside down ?


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## Shortround6 (Jul 31, 2018)

Because you have to get the power from the crankshaft (now top of the engine) down to near the line of the axles. 
A long complicated gear train or a shaft with bevel gears at each end?


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## tyrodtom (Jul 31, 2018)

Timppa said:


> So why are these engines not upside down ?[/QU


I'm not trying to say they inverted the engines to make them easier to work on, it was just a side benefit.
After over 50 years of working on various types of engines, it's rare to see any evidence that any were engineered with ease of maintenance in mind.

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## GrauGeist (Jul 31, 2018)

Apart from a benefit of better visability over the cowl, an inverted engine has a lower center of gravity.


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## pbehn (Jul 31, 2018)

Don't radial and rotary engines demonstrate that there is no "right way up"?

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## Clayton Magnet (Jul 31, 2018)

I had always assumed that an inverted engine would struggle with oil consumption, but that doesn't seem to be the case with the DB series. Did the DB engines have a better scavenge system?


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## swampyankee (Jul 31, 2018)

GrauGeist said:


> Apart from a benefit of better visability over the cowl, an inverted engine has a lower center of gravity.



Vertical C/G is not terribly important for aircraft. A higher thrust line permits a larger propeller or shorter landing gear, but thrust line in a geared engine isn't dictated by the location of the crankshaft. Indeed, it can't coincide with the crankshaft if the idea is to have a cannon firing through the hub.

An inverted engine probably adds more problems, especially oil scavenging, than it solves. Radials are notorious for getting oil in the cylinders below the crankcase; it's extremely unlikely that inverted v-12s would be better in this regard.

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## YF12A (Jul 31, 2018)

Two ways to look at that. When a P-51 etc, is upside down, its' Merlin is inverted. And all Radials have some inverted cylinders.


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## GrauGeist (Jul 31, 2018)

I don't see how an inverted engine would have an


swampyankee said:


> Vertical C/G is not terribly important for aircraft. A higher thrust line permits a larger propeller or shorter landing gear, but thrust line in a geared engine isn't dictated by the location of the crankshaft. Indeed, it can't coincide with the crankshaft if the idea is to have a cannon firing through the hub.
> 
> An inverted engine probably adds more problems, especially oil scavenging, than it solves. Radials are notorious for getting oil in the cylinders below the crankcase; it's extremely unlikely that inverted v-12s would be better in this regard.


Disagree - some equipment aboard an aircraft may or may not have much influence on flight characteristics outside of fuel cells), but an engine is a large portion of weight that can have a direct influence.

As far as inverted oil issues, several manufacturers were making inverted engines long before WWII, like Packard's V-1650 (L-12-A) and Allison's VG-1410, developed in the 1920's.

By the way, on a radial, you "push through" the engine before starting and that puts the oil back in the crancase and prevents hydro-lock. 

And if an upright L or V was so critical, then the H or "boxer" would never have made it this far.


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## tyrodtom (Jul 31, 2018)

The two main ways engines lose oil to the combustion chamber is through the cylinder walls/ rings , and valve seals.

On a conventional V or inline engine the oil stays on the cylinder wall, but most is scraped off by the piston rings, and that is assisted by gravity in pulling that oil down. But the valves are facing down, oil trying to get past the valve seals into the combustion chamber will be assisted by gravity.

In a inverted engine the leakage past the rings may be assisted by gravity to get past the ring seal, but the leakage past the valve seals may be less than a conventional mounted engine, gravity isn't going to assist in the oil flowing up the valve stems.

So the conventional engine has better ring seal oil control, than the inverted engine, but the inverted engine has better valve seal oil control. So they might end up being close to the same overall in oil lost to the combustion chamber.

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## P-39 Expert (Aug 1, 2018)

I think the 109's inverted engine gave a better view over the nose, but then again had the thrust line lower causing a bit longer landing gear.


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## Shortround6 (Aug 1, 2018)

It helps to see where they were coming from.










The huge BMW V-12 (46.93 L) was essentially two WW I six cylinder banks using a common crankshaft. 




It was tall and wide.
Requirements for better vision are not hard to understand even if they didn't quite work out as planned. 
Small cockpit with low roof tends to negate the advantages of the inverted engine, especially after they substituted teh DB series of engines for the smaller Jumo 210.


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## David Fred (Aug 4, 2018)

Shortround6 said:


> There was a lot of contradictory thinking going on.
> 
> Like,
> 
> ...


Like “The bomber will always get through”. Like 8.303’s are better than 4-6 .50’s. Like the “Big Wing”, which Allen hates in his book, as did Leigh-Mallory and Dowding


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## David Fred (Aug 4, 2018)

Two other fabulous books.


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## Shortround6 (Aug 4, 2018)

David Fred said:


> Like “The bomber will always get through”. *Like 8.303’s are better than 4-6 .50’s.* Like the “Big Wing”, which Allen hates in his book, as did Leigh-Mallory and Dowding



We have a number of threads on the bolded part.

There is no doubt that 4-6 .50 cal guns from 1943 firing 1943 ammunition are much better than eight .303s from 1940 firing 1939/40 ammunition. 
_BUT _that was not the choice faced by the British in the mid and late 30s or even in 1940. 
They had choice of eight .303s or basicly four late 1930s .50 cal guns (six were too heavy for the engines avialable). 

The .50 cal was under 600rpm when tested by the British and did not go to the 750-850rpm numbers until very late 1940 or early 1941. 
so it is 150-160 .303 bullets per second vs 36-40 . 50 cal bullet per second not the 52-56 bullets per second of the later war US fighters with 4 guns. 

Then we have the ammo problem/s. 
When tested by the British the .50 cal had a MV of about 2500fps. about 60fps more than the .303. 
The US changed the type of powder used as propellent and got the MV over 2800fps _but not until after 1940. _
so striking power was much less than later ammo, about 20%.
The US didn't seem to have any incendiary ammunition for the .50cal or at least not very effective incendiary ammo. The M1 Incendiary is pretty much an enlarged
de Wilde bullet as developed by the British. This does not show up until well after the BoB. By 1943 the US is phasing that out and switching to the M8 API round in which every AP round has a small charge of incendiary material in the nose and not using mixed belts of different types of ammo. 
Thinking you could get 1943 P-51/FM-2 gun power in a British fighter in 1940 without a time machine is just wrong.

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## David Fred (Aug 4, 2018)

Shortround6 said:


> We have a number of threads on the bolded part.
> 
> There is no doubt that 4-6 .50 cal guns from 1943 firing 1943 ammunition are much better than eight .303s from 1940 firing 1939/40 ammunition.
> _BUT _that was not the choice faced by the British in the mid and late 30s or even in 1940.
> ...



Well, Wing Commander, H.R. Allen, DFC in his book “Who Won the Battle of Britain” (ph. 79-80) disagrees. And “Flying Guns Of World War II” says the AP. 303 used at that time had no explosive content. The cartridge was a 7.7x56R. The incendiary version had 1/2 gram. It also had a slightly lower muzzle velocity (747 meters/sec. (Pages 330 and 331) of the Flying Guns book I have uploaded in other posts. And the incendiary round was NOT armor piercings

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## swampyankee (Aug 4, 2018)

David Fred said:


> Like “The bomber will always get through”. Like 8.303’s are better than 4-6 .50’s. Like the “Big Wing”, which Allen hates in his book, as did Leigh-Mallory and Dowding



..or like 6 - 0.5 in are better than 4 - 20 mm?

The choice of 0.303 in was actually the result of testing in the 1930s, which showed that the effect of individual 0.5 in was not proportionately greater than that of 0.303 in. 

The "bomber will always get through" was the result of two simultaneous logical errors: first, that the defensive armament of bombers would be devastating against interceptors and, second, that civilian populations would collapse into anti-government revolution when a couple of bombs dropped someplace in the neighborhood.


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## Shortround6 (Aug 4, 2018)

The .303 AP had no explosive content but the .303 De Wilde was loaded in at least one gun of the eight and each .303 incendiary bullet held 7 grains of material. Which is just under 1/2 gram. But one gun was firing 19-20 bullets a second. Tests showed this bullet was about twice as likely to set a fuel tank on fire as the .303 incendiary/tracer. There were not enough to supply more than two guns per plane.

But the .50 cal ball and AP of the 30s and 1940 also had no explosive content. The US may not have had an incendiary round yet approved. The British didn't like the samples they got and designed their own. This leaves the .50 cal tracer as the only .50 cal projectile at the time with any hope of setting fire to anything. 

The incendiary bullet may very well have had a velocity of 2370fps but the ball was 2440 and the AP was about 2500fps. This difference is pretty trivial compared to the 2500fps to 2800fps difference in the .50 cal ammo. ALL of the early .50 cal ammo was about 2500fps. The bullets were slightly heavier than the later ammo. 

To make a difference in the BoB you would have needed a factory tool up to make the .50 cal guns by the thousands per year (US could barely supply their own and a few exports in 1939/40) and factories making millions of rounds of ammo before the BoB. The British had given Remington a large contract for ball, tracer, armour piercing and drill ammunition for RAF use in American aircraft purchased in 1940. They also got ammo from US government contracts VIA the US Steel Company contracts. US Steel was used to buy "surplus" US military equipment and supplies and then resell it to the British in order to keep up the facade that the US government was neutral. 

The plain facts are that the early .50s didn't fire as fast in rounds per minute (or second) their muzzle velocity was lower and the ammo was deficient in the quantity of incendiary material fired per unit of time compared to the same number of guns in 1943.
Now the quartet of early .50s may have been better than eight .303s but by nowhere near the margin the later guns and ammo would have. 

Now let's put six .50s and 235 rounds per gun (807lbs) in a Hurricane with a 2 pitch prop and see what happens to climb and ceiling? 
The eight .303s and 334 rounds per gun went about 433lbs.
Four .50s with 250rpg is going to go around 556lbs.

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## Greyman (Aug 4, 2018)

Might as well post my message from this thread again;



Greyman said:


> I gotta say, "the bomber will always get through" has to be one of the most misunderstood quotations.
> 
> The idea wasn't that bombers would always get through to their targets no matter what the enemy did to defend - it was that no matter how much effort you put into defense, your cities wouldn't escape being bombed.


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## pbehn (Aug 4, 2018)

Greyman said:


> Might as well post my message from this thread again;
> 
> *I gotta say, "the bomber will always get through" has to be one of the most misunderstood quotations.
> 
> The idea wasn't that bombers would always get through to their targets no matter what the enemy did to defend - it was that no matter how much effort you put into defense, your cities wouldn't escape being bombed*.


Yes, but in many cases the cost of bombing was greater than the cost of being bombed, the effect of being bombed was grossly overestimated. Germany had to call off its bombing offensives against UK in daylight and then at night. Italy's assault n UK never got started. The British attacks on Germany had little effect until 1942/3 when the war was half way through.


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## David Fred (Aug 4, 2018)

A Wing Commander as I mentioned already goes through everything you say in detail, and disagrees. So believe what you wish.
And 4 Hispano II were not available in the BoB, and two bladed props were not used.

But have it your way.


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## Shortround6 (Aug 4, 2018)

David Fred said:


> A Wing Commander as I mentioned already goes through everything you say in detail, and disagrees. So believe what you wish.
> And 4 Hispano II were not available in the BoB, and two bladed props were not used.
> 
> But have it your way.


I have the book but haven't read it yet. 

I did not mention two bladed props, I said two pitch props which were a totally different thing.


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## GrauGeist (Aug 4, 2018)

David Fred said:


> And the incendiary round was NOT armor piercings


The *M8 API *most certainly was. API: Armor Piercing Incendiary.

Perhaps you're confusing that with the *M23 Incendiary *ammunition, which was solely incendiary?


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## Greyman (Aug 4, 2018)

The results of the air fighting show that the .303-inch Browning was certainly effective enough. Better tactics, more training, and at least _some_ gunnery training would have helped far, far more than a tiny (at best) upgrade to .5-inch guns.

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## Shortround6 (Aug 4, 2018)

David Fred said:


> A Wing Commander as I mentioned already goes through everything you say in detail, and disagrees. So believe what you wish.



OK I have read the first 4 pages in the chapter on armement and he not only makes the same mistakes others do on what the the cycle rate of the Browning .50 cal was and when but also falls into the same trap of using the 1941-42 ammo for his ballistic comparisons rather than using the 1930s/1940 ammo. In fact he may be using too high a velocity for the .50 cal.
You will find many sources claiming the .50 cal has a muzzle velocity of 2900fps, which is what the author uses. This may very well be _correct for some guns_.
However the ground guns as Used by the US army in WW II and the water cooled AA guns used by the Army and Navy used 45 in barrels. The Aircraft guns used 36 in barrels. Either the ground guns are carting around 9 in of barrel too much or one can expect some sort of velocity loss for the aircraft guns.
The loss of some initial velocity is not that important to aircraft guns as due to the thinner air they are fired in (at much above sea level) they don't slow down as much as bullets fired at sea level and so have shorter times of flight and hit while still moving at a higher velocity.

I do like this sentence:
page 81 second sentence of the first paragraph:
" The Colt was, in effect, a minor quick-firing cannon and it's bullets could contain warheads designed for explosion on impact, incendiary purposes or the piercing of armor; naturally, with it's greater muzzle velocity , the Colts armour-piercing ability would be considerably more effective than that of a Browning bullet, and to this consideration must be added the bullet weight which is was over four times greater in the former than in the latter."

Sounds like a Colt salesman.
Let's be clear here, the .50 cal Colt *NEVER *had a bullet that exploded on impact issued for service use in WW II, let alone in time for the BoB.
It is highly doubtful that ANY SORT OF INCENDIARY ammunition (aside from tracer) was available in time for the BoB although it did become available later.
Even at 2500fps the .50 will penetrate more much more armour than the .303 in large part due to it's greater weight per unit of frontal area.

His nice little table has some mistaken assumptions. Like the 2240fps mv for the .303 MK VII. an easy typo but he use that to figure out his muzzle energy figures, if you use the correct velocity of 2440 fps the muzzle energy goes up 18% for the .303 and if you use the correct bullet weight and velocity for the .50 cal ammo as it existed in 1940 it's muzzle energy goes down a bit over 21%. Once you correct the rate of fire to 600rpm for the Colt .50 (which is being generous for 1940) and also change the .303 Browning down from 1350 to 1150rom the Colts energy advantage shrinks from over double to about 18.7% which is nice but not an overwhelming blow them out of the sky advantage that the author claims.

The author also makes a few other leaps of faith or judgement. Like relating the story of Group Captain Peter Townsend and an engagement where he fired at and damaged a german bomber that made it back to base with 220 hits from the .303 which is very good shooting indeed. The author then asks what would would have happened if the German had been hit by 220 .50 cal rounds. Interesting question but it rather glosses right by a few facts. One, Group Captain Townsend may have fired his entire load of 2400 rounds (if a Spitfire I, more if a Hurricane or SPitfire II) and with equal accuracy a load of 2400 rounds of .50 cal ammo weighs 720 lbs and not the 160lbs that 2400 rounds of .303 ammo weighs. Two, Group Captain Townsend had about 17 seconds of firing time. it would have take 60 seconds to fire 2400 rounds of .50 cal ammo from four 1940 Colt .50s.
The author then goes on to say "after ten such strikes, the bomber would have exploded with such ferocity as to have put Townsend's life in danger from the resulting flying debris."

Really?? no HE ammo, no incendiary ammo, tracers make up what percentage of the belt, 20%? if used at all?

I am not sure 10 20mm strikes would have destroyed a German twin engine bomber in such a fashion unless the bombs in the bombay blew up. The chances of ten .50 strikes blowing up a bomber in such a fashion are slim and none and slim has already left town.

Please note I am not saying that it was impossible to shoot down a bomber with 10 .50cal hits. Just that the likelihood of the bomber blowing up with such ferocity that the fighter pilot is in serous danger from flying debris is a more than bit much.

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## Greyman (Aug 5, 2018)

During 1941 trials vs. a He 111, the British figured 10 rounds of .5-inch Winchester AP had a 23.2% chance of downing the bomber in a stern attack. This was entirely due to damage in the engine area (immediate lethal damage to the supercharger, fuel system, oil system or coolant system).

If the .5-inch AP round managed a leak in one of the self-sealing tanks it was not considered lethal. No .5-inch incendiary round was used in the trial. I suspect for the reason Shortround mentioned; none available until sometime in '42.

To get about the same percentage, the .303 Mk.VI incendiary needed about 22 strikes and the .303 Mk.I AP needed about 24. Hispano HE/I needed 4.

Sholto Douglas thought the results/conclusions of the trial were rather optimistic.

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## swampyankee (Aug 5, 2018)

Greyman said:


> Might as well post my message from this thread again;



It wasn’t just the bombing, but the thought that civilian morale was so fragile that any bombardment would cause crippling social disruption.


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## David Fred (Aug 5, 2018)

Shortround6 said:


> I have the book but haven't read it yet.
> 
> I did not mention two bladed props, I said two pitch props which were a totally different thing.



The MkIa had a Rotol Constant Speed 10’9” prop.


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## Shortround6 (Aug 6, 2018)

David Fred said:


> The MkIa had a Rotol Constant Speed 10’9” prop.


ANd when did they get them?

The first 77 (?) Spitfires got the wooden 2 blade fixed pitch airprops, then they changed to the DH 3 blade two pitch prop. and there they stayed until the late spring of 1940. They trialed the Rotol prop in the fall of 39. but actual production started when? 
from June24th to Aug 16th 1940 there was a mad scramble to refit all the Spitfires and Hurricanes with two pitch props to constant speed operation. This could be done using a new pump/controller on the engine and a new cockpit control using the existing propeller. However this more than bit late to also try changing the armament of the existing fighters.


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## David Fred (Aug 6, 2018)

Well, until you get your hands on Allen’s book, there isn’t much more to discuss.
His idea wasn’t to re-equip existing fighters, he says the RAE and Air Staff made the wrong decision to begin with. That Four .50 BMG would have been a better choice, and provides RAE test data comparing the energy delivered (minus the gram or so explosive in the .50 API round, kinetic energy only). And the .50 would exact a weight penalty of 36 kg, but the Mark 1a had more horsepower.

I took his test data, and just multiplied it, i.e. 8 .50’s would deliver twice the energy, 6 would be 1.5 times. He doesn’t say what methodology was used for the tests, but it’s not relevant, as the test conditions were the same for all weapons. I built the attached table.

Look, I don’t have a horse in this race. I don’t care. I thought this site was about information exchange, not pissing contests. I’m only telling you what one senior RAF officer says in his book, and it is clear that 4, or even 2 Hispano 20mm cannon are superior to both, especially for bomber work, if for no other reason than around 10 grams of explosive per round.

I tried to find a pdf file to send, since a lot of that stuff is out there now. No luck, and I didn’t want to have knock on my door about copyright infringement,

At any rate, I have offered all I can on the topic. Make of it what you will.


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## Shortround6 (Aug 6, 2018)

You can print in multi color or tuttie-fruttie. 
You can print it large font or huge font. 

It doesn't change the fact that 
*The numbers are wrong*. 

Mistake #1
The Muzzle velocity of the .303 MK VII ball was 2440fps not 2240. 

See: .303 inch Ball Mark VI to VIIIz & L1A1 - British Military Small Arms Ammo

Or most any other website. 

That changes the energy to about 2300ftlbs per round. 

Mistake #2

The numbers for the .50 cal ammo are wrong for the the 1930s and 1940. 
The US M1 Ball and M1 AP used a 750 grain (48.6 gram ) bullet at 2500fps. 

That changes the ME to 10,407ft pounds from the listed 13,250ft pounds.

Again see .50 inch Browning Ball - British Military Small Arms Ammo

I also have ballistic tables and penetration tables for .50 cal ammo using this weight bullet and velocity as published in "Ammunition" By Melvin Johnson and Charles Haven. This is the same Melvin Johnson who designed the semi-automatic rifle and LHG that bear his name. 
The lighter bullet/higher velocity round (the M2 ball and M2 AP) did not exist during the times the RAF were evaluating the .50 cal gun before the war and in fact the it was the heavy bullet/lower velocity round that the British purchased in 1940 for the .50 cal guns they did have. The M2 ammunition required a different formulation of powder than than the M1 rounds used. 

Without Dr Who and a Tardis (time machine) there is simply no way around this problem.

Mistake #3 The pre war guns didn't fire at the rate of fire given in the book (which I do have, I just hadn't read it before some of the initial posts) 
The Pre war guns fired at best at 600rpm (using short belts, long belts slowed them down) and even the later guns are listed in the manual (April 1942 publication date) as firing 700-850rpm. Taking the highest possible figure is not making a fair comparison. 

Mistake #4. The M8API round with the 1 gram of _incendiary material (*not explosive*) _Doesn't show up until 1943. An incendiary round (M1 incendiary) was available sooner but NOT at the time of the BoB. This round contained about 2.5 grams of _incendiary material_ but again, no service .50 cal round carried explosives. 

The Air Ministry did make a lot of mistakes, failing to use a time machine to bring back weapons and ammo from the future was not one of them.

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## David Fred (Aug 6, 2018)

Wow. The RAF must have had some pretty shitty senior officers, as the numbers came straight from his book.

You should have higher standards.


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## Ascent (Aug 6, 2018)

David Fred said:


> Wow. The RAF must have had some pretty shitty senior officers, as the numbers came straight from his book.
> 
> You should have higher standards.


Just being an RAF officer doesn't make you correct, no matter how senior. I've met way too many of them to believe that.

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## Shortround6 (Aug 6, 2018)

I can't help it if he is wrong. 

His numbers (except for the MV of .303 and the _average _rate of fire for the M2 ) are actually correct for guns and ammo form around late 1941-42.

Just because he made wing commander doesn't make him the 2nd coming of Moses coming down from the mountain with tablets from God. 

Look up the numbers for yourself.


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## fastmongrel (Aug 6, 2018)

David Fred said:


> as the numbers came straight from his book.



Ever thought an author might be trying to sell his book. There's nothing sells better in Britain than a book that makes us feel good about losing the 2nd world war and able to blame some high ups for the disaster that was the Battle of Britain. 

Seriously though this book is just one of many that tells one version of history. Never rely on one book or one point of view, read a range of books or articles by different authors. Even do a bit of research it's not that hard most of the records are available. I recently spent two weeks off sick looking up figures of losses and victories for the Battle of France for all combatants and never left my bedroom.


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## GrauGeist (Aug 6, 2018)

David Fred said:


> Wow. The RAF must have had some pretty shitty senior officers, as the numbers came straight from his book.
> 
> You should have higher standards.


I can see from this attitude, that you're not even willing to listen to facts, even though they have politely been repeated in clear and accurate detail.

Just because something comes from a book, doesn't mean it's 100% accurate. If so, then we should believe such things as Green's myth that a Ju390 flew to the east coast of the U.S. - which facts proved it didn't.

Just as now, facts (from several solid resources) are proving that there's errors in the books you're using as a basis for your argument.

Perhaps take a little time to check those sources provided and be better informed?

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## Shortround6 (Aug 6, 2018)

Any number of books, instruction manuals and websites will confirm the 2440fps velocity from the .303 cartridge MK VII from Lee-Enfields, Bren guns, Lewis guns, Vickers guns and others. They all had 24 in barrels give or take an inch or two. Why the Browning aircraft gun would loose 200fps of velocity from the same length barrel defies belief.

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## Greyman (Aug 6, 2018)

Official Air Ministry publication on gun sights has ballistic tables for .303-inch Mk.VII ammunition and list 2,440 fps for muzzle velocity.

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## yulzari (Aug 7, 2018)

I came here late for the current argument over the number of angels who can dance on the head of a pin/MG performances.

The situation at the point pre war when the RAF was looking at something better than the .303" was that the Browning 0.5", at that time, was not a class improvement over the multi .303" weight for weight. Better yes but not in another whole class. The 20mm cannon however was in a different class and they made a very reasonable decision, at the time, to skip the 0.5" and go straight for the 20mm cannon. You can argue the detail of each class's performance but they still fall into the same three classes.

Whatever the 0.5" Browning may have become later on they had no hindsight to employ and made a quite proper decision. 

BTW had they wanted to go to a 0.5" Browning (probably in 13.2mm form) it may well have been via FN a short ferry ride away rather than with Browning themselves across a whole ocean.


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## Shortround6 (Aug 7, 2018)

Going to the 13.2mm just means screwing up the supply chain.

British are going to adopt an American cartridge (for which exist several production lines, that may or may not be involved in a European war) or French/Belgian cartridge, with fewer/smaller production lines that have the possibility of being cut off? (Belgian if not French?)


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## Clayton Magnet (Aug 7, 2018)

Is it known when the Air Ministry decided to pursue the Hispano as a replacement/compliment to the .303? Must have been in the late 1930's, as they were being trialed in 1940


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## Shortround6 (Aug 7, 2018)

The British MARC company deed of partnership was filed Jan 11, 1938.
It was established with a capital of 100,000lbs.
The title deeds for the plots of land for the factory were recorded in June of 1938.
Machinery was purchased in Britain and the United States. 
At the official opening on Jan 1939 the Duke of Gloucester fired the first British HS 404. 

Which really points to when/how they could have squeezed in the .50 cal Browning.


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## Clayton Magnet (Aug 7, 2018)

And HAD the HS 404 been successful in a wing mount installation in 1940, the question of why they never selected the .50 M2 would be even less realistic. Considering as well, that the .50 was also initially troublesome in wing mounts. And was mounted in the engine cowl, in single installations at that time

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## yulzari (Aug 8, 2018)

Shortround6 said:


> Going to the 13.2mm just means screwing up the supply chain.
> British are going to adopt an American cartridge (for which exist several production lines, that may or may not be involved in a European war) or French/Belgian cartridge, with fewer/smaller production lines that have the possibility of being cut off? (Belgian if not French?)


What supply chain? If they chose 13.2mm the supply chain would be all 13.2mm. The production would be in the UK for both gun and ammunition and FN can supply the tooling designs. Not hard. Even the Swedes made a 13.2mm. I am not advocating FN over Browning I just mention that they are closer and used to dealing with similar clients.There are issues over sizes, material and stock sizes and machining practices to be worked out in taking on any foreign gun but this did has never deterred the British. They did the Bren gun the hard way converting Czech metrics etc. to UK standards which took too long so they simply made the BESA in metric just as the Czechs designed and made it complete with 7.92mm ammunition. There was no assumption that an RAF Browning 0.5" gun would be made the same as the USA ones nor that the ammunition would be coming from the USA. The .303" differed from the us design and used British ammunition.


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## Shortround6 (Aug 8, 2018)

The British got hundreds of thousands of rifles and millions of rounds of ammunition in the first World War, in addition to artillery guns and ammunition and great quantities of other goods/military equipment. 
I find it hard to believe they would abandon that supply source. 

The Americans had gotten burned in the first World War when they did join in with too many factories geared up to make foreign weapons/ammo that the US did not really want and was forced to improvise weapons to make do with what was in production. 

If Britain had no supply chain (factories with tooling for .50 cal ammo) and was creating a new one do you go with the European caliber or for the American caliber? 

I would also note there were several problems with the .50 or 13.2 mm guns as they stood in the late 30s. Actual performance may not have lived up to advertised performance (it didn't on the American guns anyway, cycle rate rarely matched the book rate). 
Once the Americans pushed the cycle rate to 700-850rpm the gun became a real barrel burner. The April 1942 manual calls for firing a 75 round burst and then waiting a minute before resuming fire at one 20 round burst per minute. If you waited 15 minutes you could fire another 75 round burst.
In Synchronized guns where the gun was pre-heated by the engine the manual recommends a 50 round initial burst and 15-20 rounds per minute after that. 
If no long initial burst was fired then the manual says 25 rounds per minute can be fired for long periods of time.

Now in combat you do what you have to do and barrel life may not be big consideration but raising the cycle rate on a gun like this is just going to make the problem worse and do it much faster. 
At some point in 1944 the US was chrome plating the interior of the barrels and/or using stelite inserts to combat barrel wear. 

Obviously an April 1942 manual was written without the benefit of much (if any) combat experience (and pease remember that the AA guns were water cooled and the ground guns used a much heavier barrel).


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## wuzak (Aug 8, 2018)

Shortround6 said:


> It was established with a capital of 100,000lbs.



lbs or £?


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## swampyankee (Aug 8, 2018)

Clayton Magnet said:


> Is it known when the Air Ministry decided to pursue the Hispano as a replacement/compliment to the .303? Must have been in the late 1930's, as they were being trialed in 1940




According to Tony Williams, it was in the early to mid 1930s, after trialing the 0.50 in Browning and determining it was barely more effective than the 0.303 in used by the RAF. I really don't have a stake in this, but it seems the RAF determined that the 0.50 in was unable to cause sufficiently greater damage to overcome its considerably greater weight and lower rate of fire.

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## Shortround6 (Aug 9, 2018)

lbs or £?

sorry, the latter. English pounds (money)
Keyboard doesn't have the "pound" symbol and pulled a brain fart.


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## Clayton Magnet (Aug 9, 2018)

swampyankee said:


> According to Tony Williams, it was in the early to mid 1930s, after trialing the 0.50 in Browning and determining it was barely more effective than the 0.303 in used by the RAF. I really don't have a stake in this, but it seems the RAF determined that the 0.50 in was unable to cause sufficiently greater damage to overcome its considerably greater weight and lower rate of fire.



Thank you for the link, very informative. Looks like the 20mm was chosen as the successor to the .303 in the 1920's, but wasn't until 1935 that the Hispano was selected to be the model they wanted.
"... A firing demonstration of a prototype to British officers in Paris in 1935 banished all thought of the Oerlikon; the Hispano was similar in size and weight, slightly more powerful and fired nearly twice as fast. Unfortunately, the processes of obtaining approval to buy the gun, setting up a subsidiary Hispano factory at Grantham (the British Manufacturing And Research Company, or BMARCO), redrawing the gun to imperial rather than metric units, testing and debugging the prototypes, then fitting them into aircraft and debugging the installations, all took too long for the cannon to achieve anything in the Battle of Britain..."


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## pbehn (Aug 9, 2018)

Shortround6 said:


> lbs or £?
> 
> sorry, the latter. English pounds (money)
> Keyboard doesn't have the "pound" symbol and pulled a brain fart.


Without a £ symbol most use GBP.


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## Shortround6 (Aug 9, 2018)

Thank you.


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## PWR4360-59B (Aug 17, 2018)

Its too bad they didn't understand super sonic airframe design when the P51 was on the drafting table. Swept back wings and fully controllable horizontal stabilizers and all that. Then when going sonic in a dive they would take it, and give a huge speed advantage.


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## Clayton Magnet (Aug 17, 2018)

Don't think that is possible in a propeller driven aircraft.


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## PWR4360-59B (Aug 17, 2018)

Many where lost in sonic dives because of reverse controls and wing design.


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## pbehn (Aug 17, 2018)

PWR4360-59B said:


> Many where lost in sonic dives because of reverse controls and wing design.




The flying tail as it was known was trialled on spitfires, there is a lot more to it than simply sweeping the wings back, you need different wings and a different air frame. 
RAE Bedford (RAE) modified a *Spitfire* for high-speed testing of the stabilator (then known as the "*flying* *tail*") of the Miles M.52 supersonic research aircraft. RAE test pilot Eric Brown stated that he tested this successfully during October and November 1944, attaining Mach 0.86 in a dive.[128]

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## GregP (Aug 21, 2018)

Regarding post 288, NONE were lost in supersonic dives. All they did was exceed their critical Mach number with going supersonic (transonic), where LOCAL supersonic flow started to occur.

Still, it WOULD have been great if they understood the transition better and could partly compensate and get higher critical Mach numbers. Methinks digital computers came a bit late for that.


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## wuzak (Aug 21, 2018)

PWR4360-59B said:


> Its too bad they didn't understand super sonic airframe design when the P51 was on the drafting table. Swept back wings and fully controllable horizontal stabilizers and all that. Then when going sonic in a dive they would take it, and give a huge speed advantage.



So, design an aircraft around a particular flight regime that it was unlikely to encounter, and if it did it would likely lose something important - like the propeller?

Sounds like a winning design philosophy!

btw, in high speed dives, Spitfires experienced lost propellers and exploding superchargers, among other, more successful, dives. The engines in these Spitfires were 60 series Merlins, just like the ones in the P-51.

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