# BoB after: how would you like to see Spitfire further developed?



## tomo pauk (Feb 14, 2012)

Again, you are in charge, this time in Supermarine during the Summer of 1940, and the task is to develop Spitfire further. What would be the main areas of interest/change/improvement? You may choose the 'mild' changes (models to enter services in 1941) and more radical (for 1942 on). 
If you think that Spitfire was developed further historically as it would be ideally, I acknowledge that in advance


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## Shortround6 (Feb 14, 2012)

Swipe a few hundred Merlin XXs from the bomber boys for starters.


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## Juha (Feb 14, 2012)

And several hundred more from Hurricane II production + a longer range version with fuel system a la Mk VII´and VIII


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## herman1rg (Feb 14, 2012)

Give the undercarriage a wide track


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## pbfoot (Feb 14, 2012)

Switch Production to the P51


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## krieghund (Feb 14, 2012)

pbfoot said:


> Switch Production to the P51



Oh Oh, In coming!!!


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## davebender (Feb 14, 2012)

The Spitfire airframe was somewhat expensive to produce. I would strive to lower production costs and replace wing mounted machineguns with Hs.404 cannon. Naturally it would get improved Merlin engines as they become available.

Any other changes are likely to increase production costs, which is the opposite of our objective. Lightweight fighters such as the Me-109 and Spitfire will remain in service to bulk out aircraft numbers. They are not a substitute for newer, larger aircraft models such as the Fw-190 and Mustang.

I agree with the suggestion that Britain acquire large numbers of Merlin engine powered Mustangs for long range missions. But airframe production should remain in North America where aluminum was in plentiful supply. Merlin engines for these Mustangs can be manufactured either in Britain or in Detroit.


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## tomo pauk (Feb 14, 2012)

Shortround6 said:


> Swipe a few hundred Merlin XXs from the bomber boys for starters.


 


Juha said:


> And several hundred more from Hurricane II production + a longer range version with fuel system a la Mk VII´and VIII



Agree about the Merlin XX; with boosts level in use from 1941 and further, maybe the Fw-190 would not be such a threat?
The increased fuel oil tankage would increase the usability of the plane, more so for all theaters, not only for Asia/Pacific MTO.



herman1rg said:


> Give the undercarriage a wide track



Good call, the Seafire would benefited also from that.


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## Shortround6 (Feb 14, 2012)

As far as the BoB, that was a done deal. While MK IIs started to be delivered by Castle Bromwich during the battle the vast majority of the fighters used had been manufactured before the battle started. 

Changing over to the metal covered ailerons sooner would have been nice and going for the MK III with a normal wing as already mentioned would have cut the need for the hi and low MK V models. One plane being able to cover both heights.


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## Readie (Feb 14, 2012)

pbfoot said:


> Switch Production to the P51



You are a card Neil...
I love Canadian humour 
John


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## pbfoot (Feb 14, 2012)

after the BOB the Spitfire production should be cut back (produce just enough for an intercepter version to protect UK) to allow for production space for an aircraft that is able to carry the fight to the LW.


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## Readie (Feb 14, 2012)

Improvements to the perfect interceptor fighter?

More power / rate of climb
More firepower. Maybe .50 MG or 20mm cannons
Move that fuel tank that burnt so many pilots
A greater range
Higher ceiling

Most of these came as a natural progression as WW2 progressed.

JOhn


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## Readie (Feb 14, 2012)

pbfoot said:


> after the BOB the Spitfire production should be cut back (produce just enough for an intercepter version to protect UK) to allow for production space for an aircraft that is able to carry the fight to the LW.



We did that with the Lancaster.

John


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## johnbr (Feb 14, 2012)

+1 on the undercarriage wide track + more fuel RR Crecy with 2 stage at 18 lb's boost.


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## Elmas (Feb 15, 2012)

herman1rg said:


> Give the undercarriage a wide track



Not an easy task, structurally.


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## tomo pauk (Feb 15, 2012)

The main near time improvement could've been the installation of Merlin XX. 
The long term change might include the development of the new wing, that would feature a wide track gear, tailored for 4 cannons per plane. Some fuel tanks in wings, too. In case the wing is of laminar type, the speed on two-stage Merlin should be akin to P-51s, with better climb. The teardrop canopy would've improved the visibility, as it did in other fighters of the era. The Griffon installation should proceed as historically.


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## wuzak (Feb 15, 2012)

Forget the laminar flow wing....

The two main things they needed to do with the Spitfire was add tankage (which was shown to be possible) and do some detail work with the radiator installation (to minimise drag).

Other areas to work on are using 4 x 20mm or 2 x 20mm + 2 x 0.50s, strengthening the win so that external tanks could be carried.

Also, dump Mk IX production in favour of VIII and XIV as soon as possible.


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## Shortround6 (Feb 15, 2012)

Sounds like you are talking about a Merlin powered Spiteful


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## tomo pauk (Feb 15, 2012)

Kinda; the wing area would not be reduced, though. I'd like to see the leading wing radiators, too, akin to that Tempest prototype.

Hi, wuzak,
Why should we forget laminar flow wing in this case?


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## Shortround6 (Feb 15, 2012)

The "laminar" flow didn't really do a lot for drag on it's own. What it did do was allow more interior volume for the same drag. Most WW II laminar flow wings only held the low drag airflow another 5-10% of the airfoil over a normal wing. In other words don't expect much of a change in performance over a normal Spitfire but you could wind up with more volume in the wings for fuel tanks.


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## pbfoot (Feb 15, 2012)

About the only thing was feasible do to make it an offensive weapon that was needed after after BOB was add range so it could go after the LW rather then being a clay pigeon for same . The LW could pick and choose when to fight and they did with great effect so unless some one has an idea to substanially increase the range by 2 or 3 times you are beating a dead horse . My little Toyota can actuallty go further on tank of fuel then the Spit


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## tomo pauk (Feb 15, 2012)

Shortround6 said:


> The "laminar" flow didn't really do a lot for drag on it's own. What it did do was allow more interior volume for the same drag. Most WW II laminar flow wings only held the low drag airflow another 5-10% of the airfoil over a normal wing. In other words don't expect much of a change in performance over a normal Spitfire but you could wind up with more volume in the wings for fuel tanks.



I see P-51 as a way faster plane, on same engine power, when compared with other planes with in-line engines about same shape size. The major difference was the laminar flow wing.
Anyway, even if the difference is cut at half between historical Spit IX Merlin Mustang, the effort would be worth it. 
Good point about the increased internal volume.

The increased fuel tankage increases usability even more for Asi/Pacific MTO; Spitfire flying over Japanese bases would've presented a major threat.


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## wuzak (Feb 15, 2012)

tomo pauk said:


> I see P-51 as a way faster plane, on same engine power, when compared with other planes with in-line engines about same shape size. The major difference was the laminar flow wing.
> Anyway, even if the difference is cut at half between historical Spit IX Merlin Mustang, the effort would be worth it.
> Good point about the increased internal volume.
> 
> The increased fuel tankage increases usability even more for Asi/Pacific MTO; Spitfire flying over Japanese bases would've presented a major threat.



"Way faster" is about 20-30mph.

But it wasn't all down to the wing. 

The Spitfire radiators were designed to use the Meredith effect, but Joe Smith admitted that the radiator intakes and exits weren't sized properly, especially the exits.

You may point to the Spiteful, with its laminar flow wing, being some 35-40mph faster than the Spitfire XIV on which it was originally based. However, the Spiteful also had a new design radiator system, similar to the system used on the Bf109.

I would say that tidying up the radiator installation would be quicker, cheaper and available earlier than the laminar flow wing. It may not make all the difference in top speed between the Spitfire and the Mustang, but it would close the gap and still maintain thehandling for which the Spitfire was famous.


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## Jabberwocky (Feb 15, 2012)

Simple, produce the Mk III!


It was a notable refinement over the original Spitfire design. The performance improvement was much like the Bf-109E progressing to the F. Unfortunately, the RAF and Air Ministry decided to go for the Mk V, as the Merlin XX had already been earmarked for the Hurricane and switching over to the much-changed Mk III would have disrupted production just as it was looking to expand Fighter Command.


Improvements over the Mk I/II:

More engine power, available at higher altitudes: 

Two speed, single stage Merlin XX replaces single speed, single stage Merlin II/XII. Early Merlin XXs had 1240 hp, pushing the Mk III to 385 mph. Later the Merlin XX was cleared for 1390 hp, pushing the Mk III up to 400 mph (in concert with some with other detail improvements, although I believe no cannon were fitted for the test flight)

Reworked landing gear:

Strengthened and raked forward, improving both ease of control during landing and stability on the ground. Would have made the Spitfire a better carrier aircraft. The wheels were also completely covered by fairings to reduce drag.

Adoption of a clipped ‘C’ type universal wing:

Slightly strengthened wing with a seven foot reduction in wingspan to increase rate of roll. C type wing had double the ammunition capacity for the Hispano than the B type wing (120 rpg). Wing area reduced from 242 sq ft to 220 sq ft.
Ailerons were shortened slightly to improve rate of roll, particularly at higher speeds

Increased fuel capacity:

95 imp gal nose tanks as opposed to 85 imp gal nose tanks on the Mk V. Even with the higher fuel consumption of the more powerful Merlin XX, ranges would have been about the same as for Mk I/II (550-520 miles, as opposed to 450-480 miles for the Mk V).

Other improvements:
Retractable tail wheel
Internal bulletproof windscreen with new panel arrangement
Reinforced engine mounts
Deeper radiator with a new boundary layer splitter and a larger oil cooler (still asymmetrical Mk V style though)
Reworking of some skinning


If the Mk III was produced, you’d see a Spitfire that was marginally slower in the climb (300-450 ft/sec) and marginally slower (1-2 mph only) than the Mk V under about 10,000 ft. Its rate of turn was also inferior to the Mk V.

However, the aircraft was much faster above 16,000 ft, better in the rolling plane, faster in a dive (both acceleration and limiting speed), easier to handle on the ground and had better control harmonisation. 

At 385 mph, the MK III was notably quicker at best altitudes than the Mk V and wouldn’t be so badly outclassed against the Bf-109F2/4 at high altitudes and the Fw-190A2/3/4 at medium altitudes. 

With a bit more fuel, its also got around 10-15% better range. Which is not much, but every little bit counts. 



To go a little further, beyond what was historically done with the Mk III:

Over 1941:

Introduce metal skin ailerons;
Add Mk VII/VIII style wing tanks, taking internal fuel all the way up to 123 gallons. Range then goes up to about 750-800 miles, enough to reach well into France, almost to the German border
Plumb the Mk III for drop tanks, particularly US/German style ‘teardrop’ tanks. Start with the 32/35 imp gal Hurricane external tanks and then add 45, 65 and 90 imp gal sizes through the year.

Fit the larger Rotol 4 blade propellers to better take the power of the Mk XX 
Fit multi-stub exhausts, replacing the older fishtail exhausts
Improve the design of ammunition feed and the heating for the Hispano (done in the later Mk Vc)

With the detail improvements and higher boost clearance for the Merlin XX, the Mk III would be a 400 mph capable fighter.


Over 1942

Refine oil cooler and radiator design (a la Spiteful) to reduce drag
More improvements to aircraft skinning, particularly improved surface finish and introduction of sunk rivets (as seen on the Mk VIII/Mk XII)
Fit Bendix ‘anti-g’ carburettor


NOTE: With 123 gal internal and up to 90 gal external, the Spitfire becomes a fighter capable of 5 to 6-hour escorts. RAF Mk VIIs in Europe did five-hour escorts to La Pallice in France (round trip of over 1000 miles), and RAF Mk VIIIs in the Pacific did one six-hour 1250 mile round trip (with 90 gal external tanks). 

With a 90 gal external tank, still air cruising range for the Mk VIII was 1180-1280 miles at 220 mph, depending on the exact engine and altitude of cruise. 

Rule of thumb is that combat radius is about 30-40% of cruising range (depending on flight profile). This gives an ‘improved Mk III’ a combat radius of anywhere from 355-500 miles. At 35% of best range, this is just under 450 miles.

This range is sufficient to put Spitfires over the Rhur, Stuttgart and Frankfurt with 15 minutes at combat power and 5 minutes at WEP. Although this is still short of Berlin. I wonder how the Luftwaffe would have reacted to escorted RAF raids over Germany in mid-late 1941?


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## Shortround6 (Feb 15, 2012)

tomo pauk said:


> I see P-51 as a way faster plane, on same engine power, when compared with other planes with in-line engines about same shape size. The major difference was the laminar flow wing.
> Anyway, even if the difference is cut at half between historical Spit IX Merlin Mustang, the effort would be worth it.
> Good point about the increased internal volume.



People are still arguing over wither it was the wing or the better radiator installation on the P-51. or perhaps a bit of both. don't forget that even a few small details can add up to a big difference. The famous 6mph speed difference for the bullet proof wind screen for the Spitfire comes to mind. and that is at 360mph or so, at 420mph the same change in drag is good for over 8mph. Throw in 2 or 3 other little differences and it becomes impossible to attribute the speed difference to any one thing.


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## claidemore (Feb 16, 2012)

Bubble canopy, asap. (which means larger pointed stabilizer asap as well)
Negative G carburator. 
Automation of throttle, pitch, mixture. 
2 x 20mm (belt fed, no 60 rd drum!) and 2 x .50 brownings, asap, instead of the 2 x 20mm and 4 x .303s. 4 x 20mm would have been nice, but then you gotta make a different wing, big hassle. sigh.

Add a bit of fuel, get a proper drop tank. 

Those are the simple things. Bigger projects would be moving the radiator to the mid/rear fuselage area (which was considered during initial development) and redesigning the wing for wide landing gear and better mounting of 4 cannons, ie a Spiteful wing (as noted earlier).


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## MikeGazdik (Feb 16, 2012)

It would be hard to do anything to the Spit. It was a near perfect defensive / interceptor. The only real combat deficit it had was range, and to get that you end up with a whole new airplane, the Spiteful. I would say keep making the traditional Spitfire for home defense, and then also make the Spiteful or license built Mustang for offense.


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## Juha (Feb 16, 2012)

tomo pauk said:


> The main near time improvement could've been the installation of Merlin XX.
> The long term change might include the development of the new wing, that would feature a wide track gear, tailored for 4 cannons per plane. Some fuel tanks in wings, too. In case the wing is of laminar type, the speed on two-stage Merlin should be akin to P-51s, with better climb. The teardrop canopy would've improved the visibility, as it did in other fighters of the era. The Griffon installation should proceed as historically.



IMHO the wider track u/c was not essential and would have needed completely new wing, so not worth of effort in those rather desperate times, C-wing incl the rake of the u/c wheels 2 ins forward to improve the ground stability and the possibility of 4 20mm cannon armament, not often used because of the weight penalty. The Mk VII/VIII type fuel system would have improved range issue considerably, so at least a short term solution.

Juha


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## tomo pauk (Feb 16, 2012)

Hi, wuzak, SR6

Thanks for pointing out about the Meredith effect, I was told on this forum before that Spit used the effect historically. Apparently not as good as P-51, though. Maybe installing the radiators in the aft hull would nicely balanced out the ever heavier engines that were to be installed from 1941 on, anyway better than my idea of mounting them on wing leading edges.
As for Spiteful being faster than similarly engined Spit, apart from having laminar wing more streamlined radiators, it also had smaller wing area (not very good idea?).

Hi, Juha,
My idea about the new wing is for long term modification, entering the production some time in 1942. The supposedly narrow track of the U/C was not something that Spit was often blamed for?IMO even with 4 x 20mm the Spit would be far better climber than P-51 (not that 2 cannons + 2 HMGs wouldn't suffice to get the job done).


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## Shortround6 (Feb 16, 2012)

The problem with major revisions is the interruption in production as Juha has said. Look at all the minor revisions that were put off, never done or delayed because of the fear of interrupted production. Other modifications depend on other developments. The Spitfires with 60 drums carried them because, at the time, there was no "working" belt feed. Once there was a working, reliable (somewhat) belt feed the Spitfire got it but there was little that the Spitfire designers/factories could do about it. 
Even the Substitution of the of the MK IX for the MK VII was done for the reason of keeping production line changes to a minimum. Now this could very well have been a mistake but very large changes (entirely new wings and/or fuselages) is probably beyond what was practical. You also seldom, if ever, get something for nothing. Changing the wing may get more speed or more volume for fuel but it may also (almost certainly) change the stall characteristics and handling. What do you want to give up for what you get?


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## wuzak (Feb 16, 2012)

The Mk IV (prototype Griffon engined Spitfire) first flew in 1941, IIRC. That lead to limited production of the Mk XII (basically the Mk V airframe with a Griffon engine) of 100 units.

The definitive version of the Griffon Spitfire was to be the Mk XX. A new, stronger wing design (not laminar flow) was to be used in the XX, but this didn't see production until late 1944/early 1945 in the Mk 21. Even then there were serious balance issues hat took time to sort out.

I can't see a laminar flow wing being around at a time which would make it useful to the war effort.


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## wuzak (Feb 16, 2012)

tomo pauk said:


> Hi, wuzak, SR6
> 
> Thanks for pointing out about the Meredith effect, I was told on this forum before that Spit used the effect historically. Apparently not as good as P-51, though. Maybe installing the radiators in the aft hull would nicely balanced out the ever heavier engines that were to be installed from 1941 on, anyway better than my idea of mounting them on wing leading edges.
> As for Spiteful being faster than similarly engined Spit, apart from having laminar wing more streamlined radiators, it also had smaller wing area (not very good idea?).



Just plonking the radiator in the fuselage doesn't guarantee that it will work. The Tornado prototype was originally fitted with a mid/rear fuselage mounted radiator (much like the Hurricane, in fact) but this didn't work very well, and the radiator was moved to the chin position, remaining there for the Typhoon and production Tempest Vs.

The Tempest I with leading edge radiators was some 20mph faster than the more powerful (by 100hp or so) Tempest II, and a little more than that against the Tempest V with the chin radiator.

I am glad that the Spitfire didn't get the belly scoop radiator - it would hav eruined the looks.

I do wonder what the effect of Bf109/Spiteful type radiators (lowline, trailing edge) would have been on a Mk VIII or XIV.


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## Shortround6 (Feb 16, 2012)

We have been over this before too. One doesn't just say "I will use the Meredith effect" and presto get a given level of drag reduction or actual positive thrust any more than one can say "I will just use an XX supercharger and get the power I want". 

The Merideth effect is essentially building a sort of ramjet engine using the heat given off by the radiator (or engine it self in an air cooled engine) to heat the incoming air instead of burning fuel in a combustion chamber in the ramjet duct and then ejecting the heated air out the rear of the duct at a higher speed than it came in. All while keeping the air flow drag going through the duct and radiator matrix (or engine cooling fins) to a minimum. It took a while to really get it "right" and some designs did work better than others as some had several more years of laboratory work to go one or had more volume to put the ducts in.


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## Juha (Feb 16, 2012)

tomo pauk said:


> Hi, Juha,
> My idea about the new wing is for long term modification, entering the production some time in 1942. The supposedly narrow track of the U/C was not something that Spit was often blamed for?IMO even with 4 x 20mm the Spit would be far better climber than P-51 (not that 2 cannons + 2 HMGs wouldn't suffice to get the job done).



In the few pilot memoirs I have read, I cannot remember much criticism of Spitfire's landing characteristics or the t/o characteristics of the Merlin powered versions, the Griffon versions were a bit different animals and needed more careful handling in t/os because of the powerful torgue and the opposite turning of the airscrew. The geometry of Spits u/c was different of that of Bf 109 and Spit was lighter tailed so less inclined to ground loop. Downside was of course that in conjuction of clearly smaller ground clearance of airscrew tips it was much easier in Spit to get airscrew tips to hit ground by braking hard than in Bf 109.

Juha


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## tomo pauk (Feb 16, 2012)

Shortround6 said:


> The problem with major revisions is the interruption in production as Juha has said. Look at all the minor revisions that were put off, never done or delayed because of the fear of interrupted production. Other modifications depend on other developments. The Spitfires with 60 drums carried them because, at the time, there was no "working" belt feed. Once there was a working, reliable (somewhat) belt feed the Spitfire got it but there was little that the Spitfire designers/factories could do about it.
> Even the Substitution of the of the MK IX for the MK VII was done for the reason of keeping production line changes to a minimum. Now this could very well have been a mistake but very large changes (entirely new wings and/or fuselages) is probably beyond what was practical. You also seldom, if ever, get something for nothing. Changing the wing may get more speed or more volume for fuel but it may also (almost certainly) change the stall characteristics and handling. What do you want to give up for what you get?



I agree that having plenty of good planes seemed like a better bet than having smaller number of excellent ones. It has to do about at what part of the war one takes the bet. I entirely agree that neglecting of Mk. VIII vs. Mk.IX was not a very good thing, and killing Mk.III was also a mistake IMO. Further, having [email protected] of P-40s or Spit Vs in 1944 just puts trained personnel in jeopardy, since the planes are just one part of any air force. 
Hence I've asked specifically about two levels of the upgrade, one (minor) to take effect in 1941, other (major) maybe in early 1943. The people at RAF or/and Supermarine were dissatisfied with Spit's wing, for example, and were to introduce a revised wing in Mk.XIV, and a new one for Spiteful. I see no problems to have a new wing in 1943 with design work starting in early 1941.
We could take a look at Hawker - from Typhoon, it took them 2 years to developed a completely new wing for Tempest. 
As for what I want to give, I'll give the low speed handling. 



Shortround6 said:


> We have been over this before too. One doesn't just say "I will use the Meredith effect" and presto get a given level of drag reduction or actual positive thrust any more than one can say "I will just use an XX supercharger and get the power I want".
> 
> The Merideth effect is essentially building a sort of ramjet engine using the heat given off by the radiator (or engine it self in an air cooled engine) to heat the incoming air instead of burning fuel in a combustion chamber in the ramjet duct and then ejecting the heated air out the rear of the duct at a higher speed than it came in. All while keeping the air flow drag going through the duct and radiator matrix (or engine cooling fins) to a minimum. It took a while to really get it "right" and some designs did work better than others as some had several more years of laboratory work to go one or had more volume to put the ducts in.



Hopefully the radiators would be of better efficiency as years go by, so the radiator of 1943 would make less drag than the one of 1941, per cooling capacity.


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## Timppa (Feb 16, 2012)

Jeffrey Quill, after his experiences in BoB made the list:

1. "Crash" programme for a huge improvement to the aileron control at high speed.
2. Major improvement to the optical qualities of the windscreen side panels.
3. Improvement in direct rearwards vision (bubble canopy).
4. Curing the problem of engine cutting under negative g.
5. Round counters.
6. Canopy de-icing, and fuel spray to wash oil deposits off the outside of the screen.
7. Cannon armament.
8. More performance and more fuel.


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## tomo pauk (Feb 16, 2012)

wuzak said:


> The Mk IV (prototype Griffon engined Spitfire) first flew in 1941, IIRC. That lead to limited production of the Mk XII (basically the Mk V airframe with a Griffon engine) of 100 units.
> 
> The definitive version of the Griffon Spitfire was to be the Mk XX. A new, stronger wing design (not laminar flow) was to be used in the XX, but this didn't see production until late 1944/early 1945 in the Mk 21. Even then there were serious balance issues hat took time to sort out.
> 
> I can't see a laminar flow wing being around at a time which would make it useful to the war effort.



US have had laminar flow wing in operative use in 1942, Japan in 1943, Germany was flying the prototype of Me-309 in mid 1942. So I see no problems for Brits to pull this one out for service use for 1943. Perhaps it just dawned too late to the designers, or people in charge?



wuzak said:


> Just plonking the radiator in the fuselage doesn't guarantee that it will work. The Tornado prototype was originally fitted with a mid/rear fuselage mounted radiator (much like the Hurricane, in fact) but this didn't work very well, and the radiator was moved to the chin position, remaining there for the Typhoon and production Tempest Vs.
> 
> The Tempest I with leading edge radiators was some 20mph faster than the more powerful (by 100hp or so) Tempest II, and a little more than that against the Tempest V with the chin radiator.
> 
> ...



The Italian 5 series had no problems with hull radiators, neither the Ki-61, but P-40 did. Wonder how good/bad the boundary layer was dealt with on all of those? So I won't push further with that; leading edge radiators are my favorites for quite a time now 
Thanks for the speed difference figures.


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## Siegfried (Feb 16, 2012)

1: Install a 'Germanic" style annular radiator (used on a tempest prototype) or the Lancaster/Beafighter style power egg installation.

This does three things
a/ it allows Rolls Royce to deliver complete engine/radiator units thus sinplifying installation.
b/ it removes the plumbing though the fueselage and wings and thus allows much more room for fuel in the wings as well as reducing weight.
c/ reduces the length of plumbing and hence battle vulnerabillity.


The Meredith effect on the Spitfire was not a particulary effective implementation.
The effect, which was widely known and understood well before
Meredith published a 'laymens paper'. Hugo Junkers, a Mechanical engineer and a thermodynaics
specialist had a patent on this dating from the 20's. 
The Me 109F had a particularly elegant system complete with
boundary layer bypass ducts. The Tempest and Typhoon did not
havw wing radiators and did well without them. AFAIKT
the Ta 152 and FW 190D-9) recovered engine 
cooling system waste heat via the radiator: note the cowling flaps
which would allow ejection of the heated air at optimal velocity.


2: Cleanup the underside smoothness of the wings. Its a bloody disgrace down there.


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## tomo pauk (Feb 16, 2012)

I've said 'wing leading radiators, like _that_ Tempest prototype', ie. not serial produced Typhoon/Tempest. Picture:

File:Hawker Tempest I HM599.jpg - Wikipedia, the free encyclopedia

The Typhoon Tempest did well, but a 20+ mph increase in speed does seem like a god thing.


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## Edgar Brooks (Feb 16, 2012)

Siegfried said:


> 2: Cleanup the underside smoothness of the wings. Its a bloody disgrace down there.


And so is your language.
There are a lot of misapprehensions being laboured under, here. The Spitfire tracking changed three times during its career. On the prototype, the legs were parallel, later they were splayed, slightly, and, from the Vc onwards, were moved forwards 2", and, hence, slightly wider. With the 21's new wing the tracking went from 5' 8.5" to 6' 4.25" an increase of 7.75".
Quill's report (I have a copy) did talk of ailerons, bullet-proof glass condensation, oil water cooling, armament armour ( he said that the pilot's head armour was too small,) round counters; he never mentioned a rear-view (bubble) canopy, canopy side windows, engine cutting, canopy de-icing, lack of fuel, or lack of performance, in fact he was adamant that it was superior to the 109. With regard to armament, he favoured retaing the 8 x .303", for straight fighter-to-fighter combat (this was September 1940 remember,) but was adamant that, for bomber work, the Spitfire needed 4 x 20mm cannon.
The Merlin XX was attractive, at first, because Hurricane production was due to end in April, 1941, but was revived so that the aircraft could be used for ground attack, for which their stability was ideal. At a stroke, this lost the XX, but this was not too serious, since, like the Hurricane, the III's fuselage was 4" longer, which made nosing-over a greater danger (hence the 2" greaker rake. By juggling with the carburettor controls, the Merlin 45, though longer, could still be fitted into the same cowling as the original I II.
So far, I've read through about 800 files, on the Spitfire, and nowhere is there any indication, from the RAF or Supermarine, of any dissatisfaction with it. The XIV wing was exactly the same as that of the VIII, so was not a special item, in any way.
The "serious balance issues," of the 21, were sorted in a month; Supermarine simply rounded-off the elevator horn, instead of keeping the more "squared-off" shape introduced on the V, VIII, IX, etc.
The Spiteful wing took advantage of the availability of the short-barreled Hispano Mk.V, which was not fitted into the Spitfire until the 24, since the Tempest got "first dibs."
Wherever you put the radiator, the pipework has to go somewhere, and a fuselage-mounted version would have deepened the fuselage quite considerably; sticking the pipes under the pilot doesn't make them any less vulnerable.


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## wuzak (Feb 16, 2012)

Siegfried said:


> 1: Install a 'Germanic" style annular radiator (used on a tempest prototype) or the Lancaster/Beafighter style power egg installation.
> 
> This does three things
> a/ it allows Rolls Royce to deliver complete engine/radiator units thus sinplifying installation.
> ...



Two problems with the annular radiator. One, they were usually fitted to aircraft that were or could be powered by radials and, two, it would require modifications to the Merlin reduction gear and housing to make space for the radiator on the nose. This would lengthen the forward fusealge noticeably.

The Tempest was designed, from the outset, to take the Centaurus. In the annular radiator installation the Sabre was not very closely cowled. 

Not sure that the Merlin XX power egg would have improved performance. It would have been convenient for production.


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## wuzak (Feb 16, 2012)

tomo pauk said:


> We could take a look at Hawker - from Typhoon, it took them 2 years to developed a completely new wing for Tempest.



Supermarines weren't Hawkers. And the Typhoon wasn't being made in the same numbers as the Spitfire.


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## wuzak (Feb 16, 2012)

And we know that Supermarines were working on two new wings during the war - to appear in prototype form in late 1944/early 1945.


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## tomo pauk (Feb 16, 2012)

That direct us at the fact that people at Supermarine were convinced that Spitfire could be improved with a better wing. A new wing would inevitably made hiccups in the production, be it in 1943, '44 or '45. With one factory changed after another, starting in winter 1942/43, the new wing would hopefully appear in all Spitfires by the end of 1943.


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## wuzak (Feb 16, 2012)

tomo pauk said:


> That direct us at the fact that people at Supermarine were convinced that Spitfire could be improved with a better wing. A new wing would inevitably made hiccups in the production, be it in 1943, '44 or '45. With one factory changed after another, starting in winter 1942/43, the new wing would hopefully appear in all Spitfires by the end of 1943.



Why do you think Supermarines could have got the wing into production a couple of years before they were able to historically?

Not sure they were after a better wing so much as a stronger wing. The Laminar flow wing was, arguably, not as good as the original Spitfire wing.


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## tomo pauk (Feb 16, 2012)

It depends about the timing of the impetus. Even the Spitfire III was featuring a wing different of that of Spit I II. So with design work starting in Autumn of 1940, my take is that service usage by 1943 is no problem.

If you could point me to the good source that would confirm that Spit's original wing was better than a laminar flow wing, that would be cool.


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## wuzak (Feb 16, 2012)

tomo pauk said:


> It depends about the timing of the impetus. Even the Spitfire III was featuring a wing different of that of Spit I II. So with design work starting in Autumn of 1940, my take is that service usage by 1943 is no problem.
> 
> If you could point me to the good source that would confirm that Spit's original wing was better than a laminar flow wing, that would be cool.



Not necessarily better than "a" laminar flow wing, but certainly regarded better than the Supermarine laminar flow wing.

No doubt the Spiteful was fast, but I don't believe it handled as well as the Spitfire.


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## Shortround6 (Feb 16, 2012)

tomo pauk said:


> It depends about the timing of the impetus. Even the Spitfire III was featuring a wing different of that of Spit I II. So with design work starting in Autumn of 1940, my take is that service usage by 1943 is no problem.
> 
> If you could point me to the good source that would confirm that Spit's original wing was better than a laminar flow wing, that would be cool.



I believe the Spit III wing was just clipped but I could be wrong. As far as the "Spit's original wing was better than a laminar flow wing", it might depend on what you are measuring. as it turned out the original wing did have a rather high mach number limit. A gentile, predictable stall helps pilots (especially lower time pilots) fly closer to the limits and reduces landing accidents. Getting laminar flow wings to actually work turned out to be a lot harder than they thought, even the thickness of the paint used to apply the national insignia disrupted the laminar flow. The difference between the wings may actually be due to the airfoil profiles used rather than actual laminar flow.


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## Edgar Brooks (Feb 17, 2012)

tomo pauk said:


> That direct us at the fact that people at Supermarine were convinced that Spitfire could be improved with a better wing./QUOTE]
> Stronger, yes, but better? The shape remained elliptical, with just a wider centre section/ tracking, and shortened wingtips. There seems to be a collective memory fade, regarding the 21; it had a new wing, both in its construction, and load-carrying/aerodynamic capabilities
> 
> 
> ...


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## tomo pauk (Feb 17, 2012)

Hi, wuzak,
Thanks for clearing your point re. laminar wing Spitfire. 
The Spiteful did featured also a considerably smaller wing area, so it's not a surprise if it's handling was worse than Griffon Spitfires, let alone Merlin Spitfires.

Hi, SR6,

Yes, the figures about dive speed limits (kindly provided by Glider in another thread) clearly put Spitfire in a league above Bf-109, P-47 P-38. The pilots of RAF were pretty experienced by 1943, so I guess they would not have any more issues than the ones flying Mustangs (that was also a heavier plane).

Hi, Edgar,

No memory fade about the wing of Spit 21; the only thing that is 'bad' with that wing was timing. Of course, I do not see Spiteful as just another Spitfire.


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## Gixxerman (Feb 17, 2012)

My answer is of course range.
It was all the Spit lacked really.....and as has been said given the UK's priorities it is completely understandable that the UK chose to concentrate on bombers straight after the BoB.


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## Siegfried (Feb 17, 2012)

tomo pauk said:


> Yes, the figures about dive speed limits (kindly provided by Glider in another thread) clearly put Spitfire in a league above Bf-109, P-47 P-38. The pilots of RAF were pretty experienced by 1943, so I guess they would not have any more issues than the ones flying Mustangs (that was also a heavier plane).
> .



It's questionable to me as to how significant this was in combat: intitial dive acceleration of the Spitifre was slower than the Me 109/FW 190 though it would speed up latter on in the dive. Me 109 dive performance improved considerably with the replacement of the horn balanced rudder with a tall tail and a balance tab: the earlier Me 109 was Mach limited by rudder overbalancing, not Mach tuck. The improvement was to the point that P-51D pilots reported being outdived by Me 109's; the P-51's dive speed being a very high dive speed indeed. The famous Mach 0.9 dives of the Spitifre were test dives with special propellors and resulted in airframe damage. Note also possibillity of other problems of the Pre mk 20 series Spitifires: aileron reversal a high speed. I wouldn't say that the Spitfire was in a league of its own at all when all factors considered.


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## Milosh (Feb 17, 2012)

Flying Limitations of the Spitfire IX (from Pilot's Notes)
Maximum speeds in m.p.h I.A.S.
Diving (without external stores), corresponding to a Mach No. of - .85:

Between S.L. and 20,000 ft.	- 450
20,000 and 25,000 ft.	- 430
25,000 and 30,000 ft.	- 390
30,000 and 35,000 ft.	- 340
Above ..................35,000 ft.	- 310 

The maximum permissible indicated airspeeds in the different heights are not being observed and are widely exceeded. On the basis of evidence which is now available the speed limitations ordered by teleprint message GL/6 No. 2428/41 of 10.6.41 are cancelled and replaced by the following data:

Up to 3 km	(9,842 ft.)	750 km/h.	(466 m.p.h.)
At 5 km	(16,404 ft)	700 km/h.	(435 m.p.h.)
At 7 km	(22,965 ft)	575 km/h.	(357 m.p.h.)
At 9 km	(29,527 ft)	450 km/h.	(280 m.p.h.)
At 11 km	(36,089 ft)	400 km/h.	(248 m.p.h.)

Except below 10,000' I don't see the Bf109 being faster in a dive.

Spitfire Mk IX versus Me 109 G - Flight Testing

Afiak, the Bf109K-4 had the same limitations.


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## Siegfried (Feb 17, 2012)

Supermarine did experiment with reprofiled, laminar flow ellipitical wings, prior to the Spitefull wings. They were not a success.

The Spitifre used NACA 4 digit airfoils which had been developed by Eastman Jacobs of the NACA. These profiles had a fairly blunt stall curve ie a plot of Cl versus angle of attack would show a smooth curve.

The NACA 4 digit series were latter replaced in many aircraft with the NACA 5 digit series, also designed by Jacobs, in which systematic variation of the leading edges of the 4 digit series priduced higher lift coefficients. (FW 190, Corsair and Hellcat used these, with the latter having good stall characteristics) however the 4 digit series did however produced a slightly more progressive stall.

The NACA laminar flow profile series were also designed by Eastman Jacobs; the idea being to let the pressure build up progressively at a carefully designed rate over a wing leading edge
whose peak thickness was around 50% of chord instead of 20%; this kept the flow laminar. The trailing edge had a fish tail look and was intended to recover pressure. 

A side effect of the profiles was
1 Much larger internal volume for strong wing spars and fuel.
2 the sharper angled leading edge leads to a higher critical Mach, which also reduces high speed drag. *This latter effect was much more significant than the 'laminar flow' effect (actually didn't work)*

The Spitifre achieved a relatively high mach limit by having a slim thickness/chord ratio in part by a slim wing though this left little room in the wing for fuel.

The best stalling characteristics actually come from ordinary rectangular planform wings in which the stall develops at the wing roots. Tapered wings (eg Me 109, P-40, FW 190) stall at the win tips first, which could lead to a spin and so these wings need either slats or "washout" (ie a wing twist to reduced angle of attack at the tips) of about 2 degrees. A elliptical planform wing stalls evenly along the whole wing (better than tapered planform but worse than square) however even though the the Spitifre elliptical wing needed LESS washout than a tapered planform wing it actually had about the same 2 degree washout as other aircraft.

As soon as one drops the elliptical planform for a tapered planform one needs MORE washout; which I doubt was added.

The gentle stalling characteristics of the Spitifre are probably ratherexaggeragted relative to other aircraft. The Me 109's stall was mild due to the slats and unlike the spitifre didn't tend to flip inverted after the stall. The US fighters also had annuciated stalls, with tail bueet providing warning. In fact the only European fighter with a harsh stall was the FW 190 and it had good handling up to the stall. It's stall at low G was very mild however under high G the wing could twist. I suspect the Ta 152 handled completely differently due to the new structure and materials. Spitifre's low wing loading gave it a tight turning radious; the weight of the wings being compensated by the power 100/130 fuel could provide.


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## Juha (Feb 17, 2012)

Never heard that RAE High Speed Unit used special propeller in their Spit PR XI in their high speed dive tests, the main point was that it was without protruding cannon barrels and it had 60 series Merlin, so it could made very long dives. Aside tail problem 109 had also aileron problem in high speed dives, that’s why in Rechlin dive tests the movement of ailerons in the test 109 was reduced by 50%. 109 was a good diver but P-51B and Spitfire had higher critical Mach number, fighter Spit and P-51B were about equal. The critical Mach number of P-51D was a bit lower than that of P-51B, IIRC mainly because of the bubble canopy, (.84 vs .82, IIRC). Max Mach number achieved in German 109 tests (with the new high tail) was .805, but maybe the hunted was sometimes ready to take higher risks than the hunter.

Juha


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## Gixxerman (Feb 17, 2012)

Siegfried said:


> *This latter effect was much more significant than the 'laminar flow' effect (actually didn't work)*



I remember reading some time back that even the Mustang's wing wasn't a true laminar flow wing.
Anyone know if this is a myth or is it the case?

Obviously the Mustang benefitted from some effect but the level of that is actually fairly low, from what I've seen somewhere (wish I could recall where).


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## Edgar Brooks (Feb 18, 2012)

Siegfried said:


> The gentle stalling characteristics of the Spitifre are probably (You have evidence of this?) ratherexaggeragted relative to other aircraft. The Me 109's stall was mild due to the slats and unlike the spitifre didn't tend to flip inverted after the stall. .


You've been reading fairy stories again; at the stall, the Spitfire never showed any tendency to go into an inverted spin. Trials of K9788 showed a tendency for "aileron snatch," which could be easily held by operation of the control column. Test reports, from K5054 onward, all state that behaviour at the stall is mild, with no wing drop, and with no terndency, at all, for a spin.


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## Siegfried (Feb 18, 2012)

Gixxerman said:


> I remember reading some time back that even the Mustang's wing wasn't a true laminar flow wing.
> Anyone know if this is a myth or is it the case?
> 
> Obviously the Mustang benefitted from some effect but the level of that is actually fairly low, from what I've seen somewhere (wish I could recall where).



The Mustang wing was unable to sustain laminarity over any significant portion of its wing. 

In theory however it was a laminar profile wing as good as any modern wing

It was a larger portion of laminarity but *not significant * nor sustainable in real opperations; metal wings: painted or painted simply have too much surface roughness. Laminarity has been achieved only in modern designs made of Glass Fibre Reinforced Plastics or similar composits. To make this realistic such designs exude cleaning detergents out of small holes drilled into the leading edges. 

Had the P-51's wing been made of GFRP it would have been genuinely laminar. (so long as an insect strike didn't ruin the surface)

One particular German sailplane has a rail beneath the wing which provides for wiper arm to clean the leading edge during flight. There was considerable German work in and before WW2 on using boundary layer suction to achieve laminarity: this was achieved on some experimental designs but was only usefull for increasing lift and handling as the size of the suction slots meant too much power was required. The development of prous wing surfaces (made of sintered materials) based on the work of Tolman and Schictling did not achieve a conclusion by wars end but became part of the intellectual war booty the allies reaped. (Even private patents were not recognised). Prandtl flew a AVA AF-1 with borundary layer suction.

The background of the NACA lamair profile is interesting: Eastman Jacobs (of the NACA) met the British aerodynamacist Melville Jones at Musolini's Volta conference. Jones had theorsised that a positive pressure gradient would secure laiminarity and tested such on a Hawker Hart. Jacobs went back to the USA where he used his bitter work enememies (theodore theorresen's) complex number comformal mapping techniques in reverse to engineer a wing with the required pressure gradients that eventually became the Mustang wing.

However the side effect was that the wing was 30% thicker but still had a higher critical Mach. The Laminar profiule wings had outstanding Mach characteristics, the series being used for the A-26 invader through to bell X-1. 

Interestingly at Mussolinis Volta conference all these same people missed Adolf Bussmann's talk on wing sweep.


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## Siegfried (Feb 18, 2012)

Edgar Brooks said:


> You've been reading fairy stories again; at the stall, the Spitfire never showed any tendency to go into an inverted spin. Trials of K9788 showed a tendency for "aileron snatch," which could be easily held by operation of the control column. Test reports, from K5054 onward, all state that behaviour at the stall is mild, with no wing drop, and with no terndency, at all, for a spin.



This would be the stalling characteristics at 1G or the landing configuration. A Spitfire stall at high g showed a pronounced tendancy to flip inverted. Don't get me wrong, the aircraft handled well. Me 109's simply mushed into a stall and remained controllable due to the slats and long tail momment arm.


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## DVH (Feb 19, 2012)

I agree with switch to the p51. The last gasp spitfire designs ( seafire, spiteful) started to look like mustangs' it was a better design. Those eliptical wings had a shelf life, the p51 laminar angular shape was the way to go.


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## tomo pauk (Feb 19, 2012)

I wonder if at Spitfire it would be possible to do something akin to what the Soviets were managed with their Yak-9T - in order to accommodate the 37mm cannon ammo, the cockpit was relocated aft some 40cm (circa 16in). In Spitfire's case, the space gained could contain a new fuel tank.


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## Juha (Feb 19, 2012)

It was not possible to put motorcanon in Merlin powered a/c.

I still think that Spit Mk III with metal ailerons and the fuel system of Mk VII/VIII was one good way to go.

Juha


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## tomo pauk (Feb 19, 2012)

Perhaps I was not being 100% clear: the purpose of relocation of cockpit 40cm further back is to make space for an additional fuel tank. I know that Merlin was not allowing for motor-cannon


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## wuzak (Feb 19, 2012)

DVH said:


> I agree with switch to the p51. The last gasp spitfire designs ( seafire, spiteful) started to look like mustangs' it was a better design. Those eliptical wings had a shelf life, the p51 laminar angular shape was the way to go.



No Seafire ever looked like a Mustang - they shared the wing with the equivalent Spitfire.

The Spiteful and Seafang had the square shaped laminar flow wings, but still looke nothing at all like the Mustang.

The main advantage the Mustang over the Spitfire was range. Surely that would take less time to fix than changing production over to the P-51? If the desire was truly there.

There's a saying I've seen befoe: "The P-51 can't do what a Spitfire can, but can do it over Berlin".


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## pbfoot (Feb 19, 2012)

wuzak said:


> .
> 
> The main advantage the Mustang over the Spitfire was range. Surely that would take less time to fix than changing production over to the P-51? If the desire was truly there.
> 
> [QUOTE/]It might have but they didn't. It only took North American 102 days to put out an airframe .The Brits never did make an equal of the P51 for range


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## wuzak (Feb 19, 2012)

pbfoot said:


> It might have but they didn't. It only took North American 102 days to put out an airframe .



And how long to put it into production?




pbfoot said:


> The Brits never did make an equal of the P51 for range



Did they really ever try?


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## Shortround6 (Feb 19, 2012)

tomo pauk said:


> Perhaps I was not being 100% clear: the purpose of relocation of cockpit 40cm further back is to make space for an additional fuel tank. I know that Merlin was not allowing for motor-cannon



It all depends if you can keep the CG in place. With a rear tank you can restrict maneuvers until full is burned off to allow the full maneuver capability, with the cockpit moved aft (along with the pilot armor and radio/electronics installation) the weight shift is not so easily changed back. How much of the rearward cockpit movement on the YAK-9T was due to the need for space for the breech and how much was keep the CG in place when replacing a 42kg cannon with a a 170kg cannon is subject to question. I have no doubt that room was needed for the breech but something had to moved to balance that cannon. Maybe they killed two birds with one stone?


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## Siegfried (Feb 20, 2012)

Shortround6 said:


> It all depends if you can keep the CG in place. With a rear tank you can restrict maneuvers until full is burned off to allow the full maneuver capability, with the cockpit moved aft (along with the pilot armor and radio/electronics installation) the weight shift is not so easily changed back. How much of the rearward cockpit movement on the YAK-9T was due to the need for space for the breech and how much was keep the CG in place when replacing a 42kg cannon with a a 170kg cannon is subject to question. I have no doubt that room was needed for the breech but something had to moved to balance that cannon. Maybe they killed two birds with one stone?



Stabillity of an aircraft requires that it be 'nose heavy' (ie center of gravity ahead of the center of lift). The tail provides down force to lift the nose and 'balance' the aircraft. It is much easier for an aircraft to cope with being nose heavy, almost impossible for it to cope being tail heavy. The solution to an aircraft being nose heavy is easy: one adds counter weights to the tail, or lengthens the tail slightly or possibly increases surface area. Often moving devices such as the compass and radio to the tail provides the counter weight. The beauty of the P-51's laimiar profile wings combined with the radiator being placed underneath was that it allowed 93 US gallons to be placed in each wing at the neutral point. Fuel depletion did not change C if G. The solution for the Spitifre and A6M was a tank above the wing and the pilot behined. A nasty way to get burned. The solution for the German aircraft was an L shaped tank behined and beneath the seat.


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## tomo pauk (Feb 20, 2012)

Shortround6 said:


> It all depends if you can keep the CG in place. With a rear tank you can restrict maneuvers until full is burned off to allow the full maneuver capability, with the cockpit moved aft (along with the pilot armor and radio/electronics installation) the weight shift is not so easily changed back. How much of the rearward cockpit movement on the YAK-9T was due to the need for space for the breech and how much was keep the CG in place when replacing a 42kg cannon with a a 170kg cannon is subject to question. I have no doubt that room was needed for the breech but something had to moved to balance that cannon. Maybe they killed two birds with one stone?



Thanks for pointing out about that; the drawings suggest that most/heaviest part of the cannon was above the wing, so the CoG was not that much effected?
In the Spitfire's case, the ever heavier engines were being installed, so there is another bird to be killed with a single stone.


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## Juha (Feb 20, 2012)

tomo pauk said:


> Perhaps I was not being 100% clear: the purpose of relocation of cockpit 40cm further back is to make space for an additional fuel tank. I know that Merlin was not allowing for motor-cannon



Hello Tmo
after rereading your message #61, I must admit that your message was clear but I wasn't thinking clearly enough.

Juha


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## Shortround6 (Feb 20, 2012)

tomo pauk said:


> Thanks for pointing out about that; the drawings suggest that most/heaviest part of the cannon was above the wing, so the CoG was not that much effected?
> In the Spitfire's case, the ever heavier engines were being installed, so there is another bird to be killed with a single stone.



It could work, some Spitfires were carrying around 90lbs of ballast in the tail. Of course view over the nose just gets worse


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## pbfoot (Feb 20, 2012)

wuzak said:


> Did they really ever try?


not that I'm aware of but Portal said it couldn't be done or so he told Churchill who asked about long range fighters to escort BC . Portal said a fighter with range to Berlin would cease to be a fighter


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## fastmongrel (Feb 20, 2012)

Siegfried said:


> The solution for the Spitifre and A6M was a tank above the wing and the pilot behined. A nasty way to get burned. The solution for the German aircraft was an L shaped tank behined and beneath the seat.



So instead of being burnt by a fuel tank in front of you behind a fire wall you are burnt by a fuel tank that you sit in. I bet loads of dead and disfigured Germans were grateful for that one.


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## Glider (Feb 20, 2012)

I admit that I thought the Spit was developed pretty well as it was. The only difference would be to install the rear tank from the Mk V onwards. It would have made a huge difference in so many ways.


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## woljags (Feb 20, 2012)

fitting some drop tanks to increase its range would have been a good idea


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## Edgar Brooks (Feb 20, 2012)

Glider said:


> I admit that I thought the Spit was developed pretty well as it was. The only difference would be to install the rear tank from the Mk V onwards. It would have made a huge difference in so many ways.


Especially by ensuring that the pilot couldn't see what was behind him, also that the airframe was completely out of balance as long as there was fuel in the tank. The only way to keep the Spitfire V balanced, with a fuel tank behind the pilot, was to fit a 270-gallon ferry tank under the fuselage (check the manual.)


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## Edgar Brooks (Feb 20, 2012)

Shortround6 said:


> It could work, some Spitfires were carrying around 90lbs of ballast in the tail. Of course view over the nose just gets worse


The Spitfires with that sort of weight were the XIVs, in which the Griffons had a downthrust angle, as well, which made the view over the nose better, not worse.


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## Edgar Brooks (Feb 20, 2012)

woljags said:


> fitting some drop tanks to increase its range would have been a good idea


They were carried under the fuselage from 1941; by mid-1943 the IX could fly non-stop from Gibraltar to Malta and Egypt.


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## Edgar Brooks (Feb 20, 2012)

Siegfried said:


> This would be the stalling characteristics at 1G or the landing configuration. A Spitfire stall at high g showed a pronounced tendancy to flip inverted..


Your source for this is......? At whatever speed, fast or slow, the Spitfire warned the pilot of an impending stall, but remained controllable; by easing off, slightly, a pilot could hold it just under the stall, and remain in control. Only a ham-fisted pilot would, with the buffeting warning him, keep pulling harder on the controls.


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## Shortround6 (Feb 20, 2012)

Edgar Brooks said:


> The Spitfires with that sort of weight were the XIVs, in which the Griffons had a downthrust angle, as well, which made the view over the nose better, not worse.



According to this: Spitfire Mk IX Weights and Loading

there were 5 X 17.5lb ballast weights in the MK IX but this may be an early aircraft an later ones had other equipment or in different locations that eliminated the weights? 

I believe some of the MK Is also required ballast when refitted with heavier constant speed propellers.


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## Glider (Feb 20, 2012)

Edgar Brooks said:


> Especially by ensuring that the pilot couldn't see what was behind him, also that the airframe was completely out of balance as long as there was fuel in the tank. The only way to keep the Spitfire V balanced, with a fuel tank behind the pilot, was to fit a 270-gallon ferry tank under the fuselage (check the manual.)


The rear tank didn't impact rear vision. As for the imbalance the Mustang had exactly the same problem and as long as you used that fuel first it wasn't a problem.
The very first Spitfires built were tail heavy and they simply put weights in the nose. As the aircraft gained weight the weights were moved to the back I don't see why that couldn't be done again.


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## Hop (Feb 21, 2012)

The most important improvement would have been to the radiators. Supermarine designed a much cleaner installation with boundary layer separation but the air ministry needed _more_ Spitfires, they weren't prepared to sacrifice numbers for minor increases in performance. It's worth remembering that in early 1941 the Spitfire was the only fighter in production in the UK or US that could take on the 109 on equal terms.



> Switch Production to the P51



You mean stop building the best air superiority fighter in the allied arsenal and instead start producing a low altitude army co-operation aircraft which wouldn't be ready for mass service use for another year? (It's worth remembering the RAF didn't get their first Mustang until October 1941, and they didn't have enough to put them in service until mid 1942).

That would leave a pretty big gap in the RAF for 18 months of the war. 

It would have meant the RAF abandoning high altitude fighters for the next 4 years. 

I don't think that was really an option.

As to adding range to the Spitfire, if it was required they could have added the enlarged forward tanks (the Spitfire had room for 95 gallons in the forward fuselage, and was later fitted with it, but the specification only called for 85 gallons, so that's what was fitted originally). They could also have added the 30 gallon rear tank used on ferry flights to Malta (plenty of room for it, and 30 gallons didn't cause much of a trim problem). Both of those could have been done with almost no effort. Fitting the wing tanks (approx 26 gallons) required some modification to the wings, but not much.

The problem with adding fuel early in the war was engine power. That's why Portal said a long range fighter couldn't compete with a short range one.

In 1941 the Merlin 40 series could provide about 1,000 hp at 20,000ft. In 1943/44, when the Mustang finally arrived as a fighter, it was using a 60 series Merlin with about 1,500 hp at 20,000 ft. 

You can't just ignore the fact that the loads carried by late war fighters were enabled by increased engine power that simply wasn't available earlier in the war.


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## pbfoot (Feb 21, 2012)

Hop said:


> You mean stop building the best air superiority fighter in the allied arsenal and instead start producing a low altitude army co-operation aircraft which wouldn't be ready for mass service use for another year? (It's worth remembering the RAF didn't get their first Mustang until October 1941, and they didn't have enough to put them in service until mid 1942).
> 
> .


Exactly , save a small production run for local air defence aircraft which were almost not needed . The Spit is a pretty aircraft but not the tool to take the fight to the LW unless you want to have air superiority over Calaisas for taking on LW it was sure outperformed in 41 -43 when Fighter command losses were higher then LW even over Dieppe they were crushed, 
recent quote

" By even the standards of many later WWII fighters, the Spitfire is extremely limited in range. With 85 gallons of fuel in a single fuel tank (95 gallons in later models), the Spitfire can be out of gas in less than an hour under combat conditions. Again this arose from the having a wing too thin to house fuel tanks, so all of the fuel is mounted in a single tank that is - ominously - installed directly in front of the pilot."


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## Hop (Feb 21, 2012)

> The Spit is a pretty aircraft but not the tool to take the fight to the LW unless you want to have air superiority over Calais



It seems to me you are targeting a very narrow time period. The Mustang wasn't a front line fighter in 1939, 1940, 1941, 1942 and 1943. From the summer of 1944 onwards the allies had bases on the continent only a few miles behind the front line.

That's 5 years when the Spitfire could do what the Mustang couldn't hope to, 5 months when the Mustang could do what the Spitfire couldn't, then 11 months when the Spitfire and the Mustang could both take the fight to the Luftwaffe.


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## tomo pauk (Feb 21, 2012)

Hi, Hop,

The ratio of 109s that might be confronting Spitfires in 1941-43 was perhaps 5:1, since as early as Spring of 1941, most of the Luftwaffe was deployed at East, 1st over Balkans, then above SU. Spitfire's production was bigger than of 109 from BoB till 1944? 
The Merlin 60 series was in production in UK already in 1942, so I see no problems that a long range fighter would be using it at that time, or at least from beginning of 1943*. With fuel tanks as you've noting, a fine long range Spitfire that is. The Mk. VIII was almost there, too bad it was not produced in greater volume used to bring war to Germany proper. 
Perhaps Portal was not aware that twin engined fighter can do the trick until the engine power is up to the standard. Of course, there is still no answer why a Sabre-powered long range fighter was not present in RAF's arsenal by mid 1943, at least.
So IMO it was much more to the doctrine, and thinking inside the box, than up to technical stuff. 

*P-51 was notably heavier anyway, and the P-51A already was there to show what can be done with 1000 HP at 19000 ft. And that is firmly in 1943, and down low it was the competitive plane already in 1942.


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## pbfoot (Feb 21, 2012)

Hop said:


> It seems to me you are targeting a very narrow time period. The Mustang wasn't a front line fighter in 1939, 1940, 1941, 1942 and 1943. From the summer of 1944 onwards the allies had bases on the continent only a few miles behind the front line.
> 
> That's 5 years when the Spitfire could do what the Mustang couldn't hope to, 5 months when the Mustang could do what the Spitfire couldn't, then 11 months when the Spitfire and the Mustang could both take the fight to the Luftwaffe.


its those 5 months that were in the mind of most historians that the LW met its end , I understand knocking the Spit to a Brit is like kicking your puppy but the fact remains it was not the aircraft it needed to be after BoB .


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## Hop (Feb 21, 2012)

> The ratio of 109s that might be confronting Spitfires in 1941-43 was perhaps 5:1, since as early as Spring of 1941, most of the Luftwaffe was deployed at East, 1st over Balkans, then above SU.



I don't think the ratio was anything like as large as that. According to Hooton in Eagle in Flames the Luftwaffe had 430 day fighters in the west in September 1941, 527 in December.

The RAF had 37 Spitfire squadrons in July 1941. 

If you look in terms of sorties, according to Hooton Fighter Command flew about 12,200 day fighter sorties in July and August 1941, Luftflotte 3 flew about 8,900 day fighter sorties in the same period. Bear in mind many of the RAF sorties would have been by Hurricanes.



> Spitfire's production was bigger than of 109 from BoB till 1944?



Spitfire production was higher in the middle of the war, 109 higher at the beginning and end. 

According to Wiki Bf109 production was 1,868 in 1940, 2,628 in 1941. Spitfire production was 1,995 between 3rd September 1940 and 2nd September 1941. Over the period it looks like the Germans made a few hundred more 109s.



> The Merlin 60 series was in production in UK already in 1942, so I see no problems that a long range fighter would be using it at that time, or at least from beginning of 1943*.



Perhaps by 1943. Of course, that's when the Spitfire VIII started production, so the opportunity wasn't lost. The RAF had already switched to night bombing so there wasn't a requirement for a long range escort fighter.



> Perhaps Portal was not aware that twin engined fighter can do the trick until the engine power is up to the standard.



Could it? Which twin engined fighters were competitive day fighters? Possibly the P-38, though it had so many problems we can't be sure. But a twin engined fighter also requires about twice the resources, and that's something the RAF certainly couldn't afford early in the war.



> *P-51 was notably heavier anyway, and the P-51A already was there to show what can be done with 1000 HP at 19000 ft. And that is firmly in 1943, and down low it was the competitive plane already in 1942.



The Allison engined P-51 was a very good low altitude, medium range aircraft. It most certainly was not a good high altitude, long ranged escort, a role it simply could not carry out due to lack of engine power.



> its those 5 months that were in the mind of most historians that the LW met its end ,



I don't think so. The Luftwaffe lost far more aircraft and pilots before then, and far more aircraft and pilots after. 

Of course, it was the time of the first major contribution of the USAAF in Europe, so it gets most attention from US historians. But by what logic do you assign criticality to 5 months in a 6 year battle of attrition?



> I understand knocking the Spit to a Brit is like kicking your puppy



Don't worry, you're offending my attachment to logic, not my sense of patriotism


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## tomo pauk (Feb 21, 2012)

Thanks for setting my numbers straight re. production numbers. 
Even so, I'd say that at least reworked radiators could be installed, if not Merlin XX itself, for the Spitfire for 1941. Germans did reworked their 109E already in 1940 to acquire the 109F, and Brits themselves were adapting the Hurricane. 

When talking about long range fighters, there was more to it than to escort the bombers to Ruhr/Berlin/Hamburg. RAF was fighting in MTO and in Asia, while supplying fighters to Commonwealth beyond. Hence most of Beoufighters, Mitchells, Bostons, Marauders were without fighter support, and Spit VIII was produced in too few numbers to cover all of those missions.

As for what when RAF was able to afford, they were building many twin four engined planes, and many of them were carrying Merlins. Even the controversial planes, Battle and Defiant, used up 3000 Merlins (without counting spares) prior 1941. Not to mention producing Blenheims after 1941 (doesn't matter they were using Mercurys). Brits even leased 600 Merlins for P-40s. So the Air Ministry had plenty of material to spare already in 1940, let alone in eg. 1942. 
The P-38 was rarely regarded as an easy prey, so I'd say it was pretty good. The twin engined fighter of conventional shape, with Merlins aboard 4 cannons seem to me like a better hores to bet than Typhoon, for example. 

About P-51 with Allison: the P-51A (Mustang II in RAF service) was able to make 370 mph at 25000 ft, 400 mph at 17500 ft (with racks), with 'yardstick' range of 1500 miles with 2 x 75 gals drop tanks. In worst case that means 400 miles of combat radius - from London to Frankfurt. Decent performance, great range. Esp. if we compare with the most common Spit of 1943, the Mk.V.


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## Shortround6 (Feb 21, 2012)

pbfoot said:


> Again this arose from the having a wing too thin to house fuel tanks, so all of the fuel is mounted in a single tank that is - ominously - installed directly in front of the pilot."



Fair is fair boys. Planes with fuel tanks that are "ominously - installed directly in front of the pilot" Include the :

P-47
F4U
Dw 520
Hawker Tempest
and others.

Planes that had the fuel tank/s in the lower fuselage/wing center section below the pilot include;

The Fw 190
F6F
P-40

and a host of others. 

If it is bad for one it is bad for all.


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## Edgar Brooks (Feb 21, 2012)

Glider said:


> The rear tank didn't impact rear vision. As for the imbalance the Mustang had exactly the same problem and as long as you used that fuel first it wasn't a problem..


I suggest you look at photos; the tank filled the area beneath the perspex at the back of the seat.  
The Mustang had the same long nose as the IX; on the shorter-nosed V, the tank had such a huge effect, it was banned from use without having the massive ferry tank; as I said, read the V manual.


> The very first Spitfires built were tail heavy and they simply put weights in the nose. As the aircraft gained weight the weights were moved to the back I don't see why that couldn't be done again


The first Spitfire Is were tail-heavy because of the lightness of the wooden 2-blade prop, hence the weights added to the engine mounts. With the arrival of the 3-blade prop, the weights were REmoved, not just moved. When armour was fitted behind the seat, equipment (a flare chute) had to be removed, to allow for it, and that weighed nothing like a fuel tank.
When the XVI received its fuselage tank, compressed-air and oxygen bottles had to be moved to the wings, as balance.


> there were 5 X 17.5lb ballast weights in the MK IX but this may be an early aircraft an later ones had other equipment or in different locations that eliminated the weights?


87.5 lbs = about 12 gallons; not a lot, is it?


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## Shortround6 (Feb 21, 2012)

The problem with daylight fighter escort is multiple. you have to provide "top cover" for the bombers. Not just fly at the bombers level but fly 3-5000ft above to stop the the Germans from getting the altitude advantage and diving through the bomber formations. You also have the speed problem. the fighters have to weave at a much higher speed than the bombers so they aren't caught with too low an airspeed when called upon to respond to the German attack. it can take several minutes to work up to high speed from too low a cruising speed. This high speed weave meant the fighters were flying much faster than the bombers and also actually flying much further do the weaving course, it tends to make nonsense out of 'yardstick' figures. Also just climb and forming up can suck up a lot of fuel. An F4U could use up 56 gallons just taking off and climbing to 25,000ft.


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## tomo pauk (Feb 21, 2012)

I do not claim that P-51A was the greatest fighter for the escort job, available in 1943. But classification that it was decidedly low level, medium range plane does not hold water either. 
Of course, any engine mounted on P-51s was making perhaps 50% more mileage than R-2800 

The weaving above bombers smells like close escort to me - perhaps 'freijagd' would be better to employ vs. a defender?


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## Shortround6 (Feb 21, 2012)

If you get too far from the bombers the enemy fighters can into firing position before the "hunting" fighters get back. There is no radar control to direct the fighters. Ideally you have some of both, some than can range forward and to the sides to help clear a path and some near the bombers to handle what doesn't get swept up or aside. How far the escorts should 'chase' interceptors is another question. Not being allowed to chase them very far just means they can regroup and attack again at _their_ convenience while chasing them too far means the bomber group has no escort from a second attack. 

Climb performance is also important and a often under rated or discounted. while two planes can have a very similar speed at 25,000ft one might be able to climb twice as fast as the other. Like a P-51 climbing at 1350fpm (760hp available)vs 2780fpm for a P-51B-1(1260hp available). Please note that the extra power will prevent speed from bleeding off as fast in maneuvers and or allow for a faster recover of speed from a maneuver, even if the maneuver is a simple 180 degree turn to position the fighter section/squadron to handle a new threat from a different direction and not true dog fighting. Please note that the much better climb of the "B" model allows it to try to chase 109s that try to escape or re-position themselves by climbing. 

It is the lack of vertical capability that held the Allison Mustangs to the lower levels. While they were fast in a straight line their ability to sustain speed or climb above original height very well meant their options were too limited. 

At lower levels things were much more evenly matched which is why the continued in use so long, but the high altitude escort role was simply beyond them.


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## Shortround6 (Feb 21, 2012)




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## tomo pauk (Feb 21, 2012)

Again, P-51A was not ideal long range escort fighter 



Hop said:


> I don't think the ratio was anything like as large as that. According to Hooton in Eagle in Flames the Luftwaffe had 430 day fighters in the west in September 1941, 527 in December.
> 
> The RAF had 37 Spitfire squadrons in July 1941.
> 
> If you look in terms of sorties, according to Hooton Fighter Command flew about 12,200 day fighter sorties in July and August 1941, Luftflotte 3 flew about 8,900 day fighter sorties in the same period. Bear in mind many of the RAF sorties would have been by Hurricanes.



Hi,
I've just browsed the 'Butcher bird', by Shackledy, and there it states that from May of 1941 there were only 2 Geschwaders in the West, JG 2 and JG 26. That means under 100 fighters.
37 squadrons makes 444 planes (if the squadron was with 12 planes), up to 592 (with 16 planes each) - I'm not sure when RAF fielded what number of planes per squadron, but a ratio of 4.5:1 seem pretty high  And then we add Hurricanes - RAF possessed quite the edge in 1941.

added: for Operation Cerberus (Channel Dash in Feb 1942), LW mustered circa 250 fighters; the number includes the night fighters from NJG 1 and planes from the fighter's school from Paris.


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## Juha (Feb 21, 2012)

tomo pauk said:


> ...I've just browsed the 'Butcher bird', by Shackledy, and there it states that from May of 1941 there were only 2 Geschwaders in the West, JG 2 and JG 26. That means under 100 fighters.
> 37 squadrons makes 444 planes (if the squadron was with 12 planes), up to 592 (with 16 planes each) - I'm not sure when RAF fielded what number of planes per squadron, but a ratio of 4.5:1 seem pretty high  And then we add Hurricanes - RAF possessed quite the edge in 1941.
> 
> added: for Operation Cerberus (Channel Dash in Feb 1942), LW mustered circa 250 fighters; the number includes the night fighters from NJG 1 and planes from the fighter's school from Paris.



Hello Tomo
a Jagdgeschwader in full streght had some 125-168 fighters depending on had it 3 or 4 Gruppen.

Juha


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## Juha (Feb 21, 2012)

pbfoot said:


> Exactly , save a small production run for local air defence aircraft which were almost not needed . The Spit is a pretty aircraft but not the tool to take the fight to the LW unless you want to have air superiority over Calaisas for taking on LW it was sure outperformed in 41 -43 when Fighter command losses were higher then LW even over Dieppe they were crushed,
> recent quote
> 
> " By even the standards of many later WWII fighters, the Spitfire is extremely limited in range. With 85 gallons of fuel in a single fuel tank (95 gallons in later models), the Spitfire can be out of gas in less than an hour under combat conditions. Again this arose from the having a wing too thin to house fuel tanks, so all of the fuel is mounted in a single tank that is - ominously - installed directly in front of the pilot."



So could 109G or La-5FN. Many good Eurepean fighters were short ranged, Spit wasn't exception.

Juha


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## tomo pauk (Feb 21, 2012)

Juha said:


> Hello Tomo
> a Jagdgeschwader in full streght had some 125-168 fighters depending on had it 3 or 4 Gruppen.
> 
> Juha



My bad, 3 Gruppen mostly, 3-4 Staffeln each, 9-12 planes per Staffel - anywhere between 81 and 144 planes. So it's 162-288 fighter planes from May 1941 on, in West?


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## pbfoot (Feb 21, 2012)

Juha said:


> So could 109G or La-5FN. Many good Eurepean fighters were short ranged, Spit wasn't exception.
> 
> Juha


But they were either a defensive weapon or in the case of the LA5 working near the front . The Spit was doing escort work for 8th AF for a while and longer for 9th AF , if the powers to be were short sighted it wasn't fair on the pilots to be doing work their aircraft was not designed for


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## Hop (Feb 21, 2012)

> I've just browsed the 'Butcher bird', by Shackledy, and there it states that from May of 1941 there were only 2 Geschwaders in the West, JG 2 and JG 26.



That's a pretty narrow definition of "west" as it only includes France. Holland was obviously on the eastern front 

Looking at the Luftwaffe claims list, the following units made claims on the channel front in the second half of 1941:

JG 2
JG 26
JFS 5
JG 1
JG 52
JG 53
ZG 76

I'm not sure what German fighter strength was in southern Norway, but as RAF squadrons were based all the way up to the Shetlands, I think they should be included.


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## Juha (Feb 21, 2012)

pbfoot said:


> But they were either a defensive weapon or in the case of the LA5 working near the front . The Spit was doing escort work for 8th AF for a while and longer for 9th AF , if the powers to be were short sighted it wasn't fair on the pilots to be doing work their aircraft was not designed for



So did 109 or at least it should, in MTO and in East daytime bombing was fairly common. also La-5s and Yaks did a fair amount of escort work, mostly near front, I admit but Yak-9D and -9DD were developed to get more range out of standard Yak airframe.

Juha


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## Juha (Feb 22, 2012)

Hop said:


> That's a pretty narrow definition of "west" as it only includes France. Holland was obviously on the eastern front
> 
> Looking at the Luftwaffe claims list, the following units made claims on the channel front in the second half of 1941:
> 
> ...



JFS 5 was a training unit, a bit like OTU, and its instructors flew combat sorties.
JG 1 had only Stab and I. Gruppe from 1 Sept 1941 onwards, when the I./JG 1 was reformed, the original had became III./JG 27 in July 40.
Only I./JG 52 stayed in Holland when Stab and II./JG 52 moved to East in early June 41, III./JG 52 had already earlier moved to Rumania. And even I./JG 52 left in Sept 41
JG 53 is easy to check from Michael Holm's site, same to ZG 76, which was a Bf 110 formation.

Juha


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## tomo pauk (Feb 22, 2012)

Thanks for additional input.
The Channel dash was involving some 250 fighters, and theoretically the 2 JGs would more than suffice. Yet, they needed to be reinforced with elements of another JG, JFS (training unit) and NJG (night fighter Geshcwader), so what would be true, real number of fighters per Geschwader in ETO?


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## Glider (Feb 22, 2012)

Blimey, all I said was that I would put the additional fuel tanks in a little earlier.


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## Milosh (Feb 22, 2012)

Tomo,
Alfred Price. Luftwaffe Data Book, 1997

online at Luftwaffe Orders of Battle 24 June 1941, 27 July 1942, and 17 May 1943

scroll down for May 1943.


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## tomo pauk (Feb 22, 2012)

Many thanks, Milosh. The table about fighters on June 24th 1941 is quite telling:
-no JG has more than 4 Gruppen
-there is only 26 serviceable Bf-109s in Norway/Finland (of -E/-T variant)
-the two JGs in West (=France in this case) have ~120 fighters each in theory, total, but only 200 serviceable combined (Bf-109s (F-1,F-2))
-in Germany/Denmark there is 38 (yep, 38) Bf-109s (Fs?)

So that's under 250 Bf-109F-1s/F-2s west from Berlin, the handful of Bf-110s (mostly in NJGs, under 80 total, far less serviceable), then 26 Bf-109Es/Ts.


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## tomo pauk (Mar 11, 2012)

Hi, all,
Could someone please provide the data about the difference in speed for a Spitfire that has retractable tailwheel vs. non-retractable; all else being equal. Thanks in advance


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## fastmongrel (Mar 11, 2012)

I have come across tests of the single prototype MkIII N3297 fitted with MkVA wings, retractable tailwheel, no guns but ballasted and a Merlin 61 giving a max speed of 414 mph at 27,200ft weight given as 7,225 pounds. 

A prototype MkIX AB 505 converted from a VC with a Merlin 61 and fixed tailwheel was tested at the same time and had a max speed of 409 mph at 28,000 ft weight 7,400 pounds. 

These tests were of prototypes not production models and there is no mention of which prop AB 505 used but I assume it would most likely be a Rotol 4 blade 10 ft 9 inch same as N3297. Also the text says N3297 was in poor condition with gaps in the engine cowlings and paint missing from the wings and ailerons.

Hope this helps I can type up the full tests if you like but my scanner isnt working. The info came from The Spitfire Story by Alfred Price pages 128 and 167


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## tomo pauk (Mar 11, 2012)

Thanks for the info, much appreciated 
The quirk is that guns installed add to the drag, so it's impossible for me to deduce what was speed with the guns, but also with retractable tail wheel.


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## fastmongrel (Mar 11, 2012)

The only tests I could find of similar aircraft with fixed and retractable tailwheel I am afraid. I would guess that the poor external condition of N3297 would make up for the lack of armament but that is speculation. Maybe there are tests of other types of aircraft that had a change from fixed to retractable during a models production run. Werent some early Bf109 Gs similar enough to late 109 Fs to make a rough comparison of speeds and maybe extrapolate a speed difference for a similar size airframe.


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## tomo pauk (Mar 11, 2012)

Thanks again, the speed loss for the Bf-109Gs is 12 km/h (7.5 mph) if the tail wheel is non-retractable, according to the data found at Kurfurst's site. 

Retain the fixed tail wheel - cost of at least 5 mph. A second-best Merlin, some 100 HP less on aggregate. All while receiving a more substantial armor armament package vs. the models of the 1940. Not good for the historical Mk.V. Luckily for the Allies, Germans made similar mistakes with their 109Gs.


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