Even with the two bladed fixed pitch wooden prop the Spitfire I is the best performing fighter in the world at the time of its introduction in 1938. Hurricane is probably number 2. I don't think that the Jumo powered Bf-109 could compete with either. just compare it to what other nations were operating at the time; P-35, P-36, F3F, MS.406, Fiat G.50, I-16, Ki-27 and A5M.
Recurring Theme in WW2 Aviation
- Thread starter Robert Porter
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Robert you are seriously starting to push my buttons. Your first post said you read a lot and then "I like to think designers are competent people but what was wrong with these idiots all through the war and constantly delivering underpowered aircraft?"
Your next post deflected the thread onto Spitfire climb performance. Your opinion on the Spitfire has changed during the course of this thread there is no "Spitfire Mk I performance or Mk II performance, there was a bloody war on. The Spitfire Mk I had a wooden fixed prop, a course fine prop and various CS props it used two different fuels and levels of boost while adding cannons armour and all sorts of other bits which add weight. My opinion is that in performance the advantages of a fixed prop against CS were marginal at 900 to 1000BHP but cleat at 1200BHP.
from wiki
In early 1940 Spitfire Is of 54 and 66 Squadrons were fitted with Rotol manufactured wide-bladed propellers of 10 ft 9 in (3.27 m) diameter, which were recognisable by a bigger, more rounded spinner: the decision was made that the new propeller would also be used exclusively by the Mk II. This engine/propeller combination increased top speed over the late Mk I by about 6-7 mph below 17,000 feet (5,200 m), and improved climb rate.[70] Due to all of the weight increases maximum speed performance was still lower than that of early Mk Is, but combat capability was far better.[33] The Mk II was produced in IIA eight-gun and IIB cannon armed versions. Deliveries were very rapid, and they quickly replaced all remaining Mk Is in service, which were then sent to Operational Training Units. The RAF had re-equipped with the new version by April 1941.[33] The Rotol propeller units were later supplemented by de Havilland constant-speed units similar to those fitted to Mk Is.
Supermarine Spitfire (early Merlin-powered variants) - Wikipedia
Your link says the Spitfire MkXIV was good in climb
The Spit MK I could match its adversary at the time, the Spit MkV could until the Fw190 arrived then The RAF got the MkIX
It was a war, keenly fought with fine margins, your earlier link "debunking the "myth" of the Spitfire matters as much to me as saying Churchill was an alcoholic (Hitler was tea total so make your choice) or Kennedy was a womaniser (show me a man who wouldnt have an affair with Monroe).
Now a serious question, in 1940 the French who had a huge aviation industry put 75 Dewotine 520s in front line service in the Battle of France, the Dewotine was between the Spitfire and Hurricane in performance. Of all the other major world powers who had any aircraft AT ALL that could have assisted the UK in the Battle of Britain?
Now a final question, the spitfire entered service with a "Malcolm hood" type canopy which everyone agrees was a boon to the pilot, these were still being retro fitted to Mustangs in late 1943, how was that?
Shortround6
Major General
In many cases the performance asked for in the initial invitations to bid was simply unobtainable at the time. Manufacturers came as close as they could and some shaded their design more to one requirement or another (top speed vs stall speed for example) . In some cases they were given a free hand in engine selection and in others they were told (or it was strongly suggested) to use a particular engine. Please look at the proceeding aircraft to see the jumps in performance sometimes being requested.
The jump from the B-18 bomber to the B-26 called for about 40% more top speed and carrying almost 20% more bomb-load 74% further. The Cube law says that to get a B-18 up to 300mph you needed 2330 hp per engine at 10,000ft instead of the 850hp that engines it had. Something had to give, top speed or bomb-load or range.
Please remember that much of the research equipment we take for granted now didn't exist. There was only ONE Wind tunnel in the US that would fit a full sized fighter fighter plane and it's wind speed was well short of 300mph.
British had NO full sized wind tunnel which lead to all the absurd (with hindsight) predictions of 370mph Beaufighters and 460mph Typhoons.
I would note that most other nations built a few clangers also. Not just the US and England.
In 1940 (generally) the 109 had an advantage over the Hurricane but on par with the Spitfire, apart from armament (RAF pilots would have loved cannon) the opposing pilots would normally have liked to change planes The Spits climb and turn performance is better for escort fighters while the 109s speed and dive performance is better for an interceptor.
And also small matters like doubling of machine guns from 4 to 8 were introduced along with pilot armour bullet proof windshields self sealing tanks, ariels lights sensors alarms and other "stuff" As previously posted the MK II was slower than the early MKis but a much better fighting machine.
- Thread starter
- #146
Robert Porter
Senior Master Sergeant
Could not agree more. Most initial deliveries of a weapons platform suffer from some form of poor performance in respect to their initial specs. F-35 is a prime example, I am pretty sure catching fire while landing was not a desired performance spec.
And the Osprey has had more than its share of teething woes. Less frequently we see it in commercial aircraft like the Boing Dreamliner catching fire from runaway batteries.
- Thread starter
- #147
Robert Porter
Senior Master Sergeant
I am in total agreement, don't understand why being in agreement is pushing your buttons. I agree that each generation improved and their was a war on. Nothing I said would seem to contradict that. However in Eisenhowers own memoirs he lamented the quality and delivery performance of lots of weapons systems. He spoke of endemic supply chain issues that resulted, in his view, of unnecessary compromises. Now I don't pretend to have his insight into the economies in play then, nor would I attempt to argue either way without that knowledge. I made a statement in response to reading the same type of complaint from multiple sources and authors. I provided references where I could.
I really think you and others are reading more into what I said than is there. It was an observation coupled with a question. Sources state A, which lead me to question B. Sorry if somehow that pushes your buttons. Was not my intention at all. But somehow I seem to have caused a lot of emotional response when I did not intend to.
- Thread starter
- #148
Robert Porter
Senior Master Sergeant
And I have never disputed that, not once. But I did say that its climb performance was poor compared to what was desired, maybe not clearly but that is and was my belief. And it is not untrue. Its climb performance increased rather dramatically once it was re-equipped with better propellors and engines.
So telling me something I agree with time and again would seem to me to not be very pertinent. In any case as I said, sorry if I caused a problem it was not my intention.
Shortround6
Major General
While the F-35 saga is depressing it also points out a major difference between then and now. The F-35 taking around 10 years from start of program (issuing requirement?) to first flight and another 9-10 years to go into service. "Progress" was much faster in the 1930s. Planes took about 3-4 years to go from requirement to squadron service and their successor was being speced about the time they first went onto squadron service. Aerodynamics, structures, materials were all changing very rapidly and sometimes new advances could only be incorporated into a new design and not just added to an existing one.
It took the US just 10 years to go from this.
to this.
Engine power went up 3.33 times
It took the US just 10 years to go from this.
to this.
Engine power went up 3.33 times
Shortround6
Major General
OK, what was the desired climb performance?
What did the Specification call for?
That is specification F10/35?
How many feet per minute was specified or how many minutes to a given altitude?
- Thread starter
- #151
Robert Porter
Senior Master Sergeant
I have no idea, the conversation discussed in the book said something to the effect that it was a disappointing climb rate initially. Remember, this is an observation I came to over reading dozens of books. Not someone specifically pointing at the Spitfire and saying it was a terrible plane.
Again, recurring theme. Not an indictment of the Spitfire.
- Thread starter
- #152
Robert Porter
Senior Master Sergeant
Exactly, I agree wholeheartedly. And the timeframe from conception to delivery has further compressed. But and this has been my point all along. We still get aircraft that underperform specs, kill pilots and crews AFTER the initial test phase. This very rarely happens in the commercial side. If the 777 had the same failure rate as the Osprey it would never have entered service.While the F-35 saga is depressing it also points out a major difference between then and now. The F-35 taking around 10 years from start of program (issuing requirement?) to first flight and another 9-10 years to go into service. "Progress" was much faster in the 1930s. Planes took about 3-4 years to go from requirement to squadron service and their successor was being speced about the time they first went onto squadron service. Aerodynamics, structures, materials were all changing very rapidly and sometimes new advances could only be incorporated into a new design and not just added to an existing one.
It took the US just 10 years to go from this.
to this.
Engine power went up 3.33 times
The military demands aircraft that operate at the edge of the envelope where commercial aircraft tend to stick mostly to tried and true and innovation cycles are somewhat slower. In fact military development is often the source of commercial innovation, just delayed.
So I don't understand why I am being so taken to task, I don't think anything I am asking about is that inflammatory or even unreasonable. The Spitfire had a poor climb rate initially that was improved upon. Poor when compared to its own successors if no other. And if you speak to a fighter pilot they don't want aircraft that just has an edge on its competition they want one that exceeds in significant fashion its competition. Heck we routinely operate aircraft today that literally can survive conditions that would kill their pilots and we still want more.
Plus and this is where I am really confused, I ASKED, I was not stating a purported fact. I said I had read many books that made the same observation that I did, and I ASKED if anyone had an idea. Last time I checked asking is not a capital crime? Is that not still the preferred method of learning? I cited what examples I could and that was the best I can do.
Not sure why some folks seem to be reading more into what was a question based on an observation than was really there. Heck I served myself, we often got first generation products that did not meet the RFP, especially during the Carter years. We did what we could to field service stuff to make it meet our needs. As has been the case since there have been armed forces I am sure.
Shortround6
Major General
A lot of crap has appeared in print and even more on the internet. A lot of this "misinformation" seems to come from some authors interpreting things without printing/posting the actual facts.
I would note that climb rates can be all over the place. One can pick and choose the climb rate even from the same aircraft to bias an argument considerably. Like climb rate at sea level or climb rate at 15,000ft? or climb rate at 25,000ft?
Instantaneous climb rate at low level or time to 20,000ft or higher?
British made their climb charts using their definition of max continuous power, or a 30 minute rating. Yes the fixed pitch prop/s really hurt the low altitude climb and forced the engine to be throttled back even more at low altitudes.
The US used Military power (basically Take-off limits) for the first 5 minutes and then dropped to the US definition of max continuous power which was different than the British. US max continuous was a one hour rating or sometimes the power level that was OK to use as long as the fuel lasted. It was higher than max cruise however and sucked fuel like crazy.
Basic effect however is that the US planes would show a higher rate of climb for the 1st 5 minutes and then a slightly lower rate of climb after that than using British "rules". Please note however that the American climb rates, at least at altitudes that could be reached in 5 minutes are very close to the combat rate of climb ( at least for early war airplanes, ie before WER ratings) while the British climb rates are NEVER the climb rate that would be used in combat (fixed pitch props excepted?). US climb rates at higher altitudes (over 5 minutes to altitude) are also under stated in regards to combat.
British climb rate when given as time to altitude is useful for figuring the time it would take for an operational plane or small group to reach a certain intercept altitude. The US time to altitude is a bit less accurate. I could be wrong, it might have been standard procedure to use max power on many climbs for first 5 minutes but I tend to doubt it.
Other nations had similar rules for figuring climb which makes it hard to figure. What was the climb rate of a Bf 109 when fitted with the clockwork mechanism that limited max power to one minute? Or are the times to altitude done at the 30 minute rating?
Planes with single speed superchargers had to pick their performance altitude or area. Even with a constant speed prop the Spitfire I when limited to 6lb boost was trading low altitude climb for high altitude climb. even going to a "combat" setting of 3000rpm and 6 1/4lbs boost at low altitude the plane was limited to 880hp at sea level. This was a result of the supercharge being set to give max power at 16,250ft without ram, which was the highest full throttle height (or critical altitude) of ANY mass produced engine in 1939 or early 1940. RR could have used different supercharger gear and gotten 1000hp for take-off and 1085hp at 9750ft using 6lb boost and 87 octane fuel but it would have cost them around 120-130hp at 16,250ft. With the constant speed prop it would have given them better climb at low levels (under 10-12,000ft) but really cost them climb rate at higher levels (over 15,000ft) and cost service ceiling.
Now in 1938-39 P&W was working on a two stage supercharger, two planes in the US 1939 fighter trials had it, but it took until early 1941 to really get it sorted out and into production, The two speed R-1820 used in the Martlet I & IV had a FTH (full throttle height) of 13500ft, in high gear, low gear was used to get more power for take-off. The two speed R-1830 use in the F4F-3A and the Martlet II & III had a FTH of 14500ft in high gear.
Maybe the Spitfire I (even with constant speed prop) didn't have the low altitude climb "desired" but since the specification didn't say with numbers what that was it is certainly subject to interpretation. But without going to a 2 speed engine (no two stage Merlins existed at the time) performance at low altitude had to be sacrificed. The adoption of 100 octane fuel solved the problem at least for combat.
Around 300hp more was available from sea level to just under 10,000ft and from there to 16,250ft the power fell to the same as teh 87 octane fuel ratings. At 13,000ft an extra 150hp or so was available. While not normally used for climbing to combat height the extra power would have a rather startling effect on climb even if no tests are available showing the difference.
I believe some of the flak you are taking comes from trying to use the website you listed as a source. There is just so much wrong with it I don't know where to begin and don't have the time at present.
- Thread starter
- #154
Robert Porter
Senior Master Sergeant
Thank you! Very concise! I believe from my Grandfathers journals that he spent time on loan to the RAF in part working with Merlin on Turbo/Super charger designs. I know he worked extensively with 2 different fighter groups in 1941 and 42, and in his opinion early Merlins were as he put it "shite" but he was a P&W guy so that may have been professional jealousy talking. He spoke extensively of the trade offs between low level climb to altitude (I have yet to see anywhere in his Journals what altitude he was speaking of), and performance and combat at altitude.
The website I used was only one of many, which on the points I was making agreed. I have no specific knowledge of the author. However my Grandfather is a first person source, he was there, and he did not like the early Spitfires and he and others fought a loosing battle to have production resources switched to planes like the Hurricane which had much longer legs than the Spit, was cheaper and quicker to build, and had similar performance characteristics to the early Spits. It was outclassed in a few areas but in the end its track record is on par at least during the Battle of Britain. The P-51 was his personal favorite but he said it even had serious teething problems especially with engines.
However in his exact words "Until they changed the Spit to a variable pitch propellor it could not get out of its own way."
Now what exactly he meant by that I don't know. He spoke of a similar issue with I think it was the original props on the Mosquito? 2 engine all wood bomber if I recall? And while I am not sure, I believe fixed pitch propellors were at one point in time common on German aircraft in the same period?
He had a single piece propellor mounted over his fireplace, it was a fixed pitch prop. In his workshop he had some type of radial engine on a stand and used it to explain how variable pitch props worked to me when I was a kid. I have of course forgotten most of it. But I do remember him demonstrating feathering! That was actually pretty cool!
He and a bunch of his contemporaries acquired and sponsored a P-51 in races during the early 70's I used to love going to the hanger and seeing them work on it! Gramps was as they say everything in front of the firewall!
wuzak
Captain
If you're grandfather was working with RAF squadrons in 1941/42 it is unlikely that he ever saw a Spitfire with a fixed pitch prop.
It is unlikely that he was working with Spitfire Is, possibly he worked with Spitfire IIs but he was most likely working with Spitfire Vs.
And a Spitfire V could, most certainly, "get out of its own way".
The trade-offs between climb and all-out level speed and performance at altitude were there for every aircraft built.
The Spitfire was optimised around higher altitudes, so suffered a little at low altitudes, but not a lot compared to contemporaries.
The Hurricane did have a longer range, but I would hardly say that it had "much longer legs".
I am actually very glad that your grandfather and the others failed to have the Spitfire replaced by the Hurricane.
In fact, the Spitfire (and Hurricane) were to be replaced by the Hawker Tornado (Vulture) and Typhoon (Sabre). This was a decision made in 1938. Those particular aircraft were supposed to do 460mph, but didn't get close (Supermarine submitted the Type 324 and Type 325 for that competition, both with twin Merlins, the 324 had a tractor layout, the 325 a pusher layout - the Type 327 was submitted no long after, and was similar to the 324).
The Typhoon and Tornado were also not available when needed most. So they had to rely on the Spitfire and Hurricane, and it was soon determined that the Typhoon could not actually replace the Spitfire.
In terms of performance, the Hurricane II with the Merlin XX, using the improved "Hooker" twos-speed supercharger and intake, 100 octane fuel, +9psi boost and constant speed prop was slower than the Spitfire I with the Merlin II, 87 Octane fuel and fixed pitch 2 blade wooden prop. The Hurricane had better climb rates, particularly at low altitude, but that's what better power gives you.
At no point in time was the Mosquito ever fitted with a fixed or 2 position prop. The prototype flew in late 1940, And de Havilland made Hamilton Standard constant speed props under licence.
You say you are in complete agreement but other posts say that you aren't. I think the mistake you are making is reading that a fixed prop was replaced by a variable pitch and then by a constant speed prop means that the Spitfires performance was poor, it wasnt. There is no maximum to desired climb performance everyone would love to get to 30,000ft in 10 seconds but that isnt physically possible. The desired rate of climb is always the best you can do and in WW2 "can we have that yesterday please".
Your poss only show that late spitfires were better than early ones, in rate of climb it was briefly inferior to some new German marques but that is engineering, later versions closed the gap and sometimes produced an advantage. The Spitfire never went into combat with a fixed prop so your Grandfather was comparing it to other Spitfires. Ditto with Merlin engines, what were they shite compared to? Later Merlins?
I suspect that since your Grandfather had the P51 as his favourite plane, he had the Packard Merlin as his favourite engine and the 4 blade prop fitted to the P51 as his favourite prop. Remind me again what was the P51s rate of climb in 1939 with a 1000BHP engine, you can use any prop your heart desires.
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IF the Air Ministry Specification demanded 8.25 minutes to reach 15,000 ft - then K5054 blitzed it in 6.25 minutes.
From Morgan and Shacklady pp 30...
The idea of discontinuing Spitfires for Hurricanes is absolute nonsense, The Hurricane was approx 30MPH slower than the Spit and the 109, 30MPH is as much as a plane can get away with without being completely outclassed. Operating over France they would be unable to break of combat and end up in the RAF version of a Stuka party, at Dunkerque they were lucky not to be caught out in the same way simply because the German airforce had not caught up with their army, they were a long way from base too.
I can't go into the converging concepts of zone and interceptor fighters here, but each had different requirements (never specified by numbers but by desired 'time to altitude') for rates of climb.
When the 'Operational Requirements Committee' met on 29th March 1935 to consider the new day/night fighter to replace F.7/30, which would become the F.10/35 Specification, it continued the policies adopted for the Fury replacement, giving speed and firepower priority over manoeuvrability and rate of climb.
All aircraft are a compromise of various factors and the Air Ministry, in the form of DCAS Courtney also had a chart which related endurance to maximum speed. For F.10/35 the desired endurance was first decided and this gave a speed, pessimistically as it turned out, of 330mph. This might not seem very fast, but in four years the maximum speed of RAF fighters had increased from 195 mph (F.7/30 a zone fighter) to 330 mph.
The Spitfire was being built to a modified version of Specification F.7/30, Specification F.37/34 for an 'Experimental High Speed Single Seater Fighter'.
The Hurricane was being built to the similar Specification F.36/34
Neither of these specifications had directly involved the Air Staff in their development. They were both products of the Air Member for Supply and Research's high speed aircraft research program. His name will be familiar, Hugh Dowding. But, Dowding was not happy that these aircraft were being absorbed into other Air Ministry specifications. With hindsight he was probably wrong to worry, after all they became the Spitfire and Hurricane, yet he issued a new specification for an 'Experimental High Speed Aircraft' (F.35/35) in December 1935.
"1. Since the time of the Schneider Trophy Race the problem of producing an aircraft in which all other qualities are to some extent sacrificed for speed has always been a matter of great importance, and aircraft have been ordered under conditions in which speed has been the primary consideration. [F.36/34 Hawker Fighter/Hurricane and F.37/34 Supermarine/Spitfire]
2. But, as the process of development work has gone on, these aircraft have tended to become absorbed among those designed to meet Air Staff requirements for the Royal Air Force. It is felt that the time has now come for a further step forward with the object of stimulation high speed development."
"Boldness and originality" were asked for, not just bolting a bigger engine on existing designs. A maximum speed of "not less than 400 mph" was asked for. When tenders were received they showed little advance over the Spitfire, and in 1937 the project was quietly abandoned.
How both the Hawker and Supermarine high speed aircraft came to be related to F.10/35 is a grey area, and some people's memories seem to have failed them. Sorley, credited with relating both to F.10/35, actually seems to have related them to the Fury day fighter replacement (F.5/34). In any event both were eventually built to a modified F.10/35, but that is NOT where there origins lay.
In conclusion, the British at this time were developing aircraft to confront a new threat, Germany rather than France. ADGB exercises had already shown the shortcomings of the zone/interceptor fighter system. The bombers likely to arrive from the continent were becoming faster and faster, they had maximum speeds higher that the contemporary generation of British fighters in some cases.
It was these factors that compelled the British to concentrate on speed and firepower, even at the expense of manoeuvrability, endurance and rate of climb. The British wanted 330 mph fighters armed with 8 machine guns (a very heavy armament in 1935, we have the benefit of hindsight) or cannon (when they decided to ignore the ban on explosive ammunition along with everyone else).
It is actually remarkable that the two fighters developed from this period, the Spitfire and Hurricane, were not only fast and heavily armed, but that they were also more manoeuvrable than almost all their contemporaries, and also possessed comparable or better rates of climb. Endurance was NOT an issue in the role for which they were designed. The Operational Requirements Committee more or less got the endurance which it had specified. The short legs of both aircraft were not an oversight, they were designed that way. Endurance only became an issue when they were forced into a role for which they were not designed.
British Fighter Specifications = Minefield
Cheers
Steve
I should add on the matter of rate of climb, that the requirements for an interceptor and zone fighter were different and seem to have confused some at the Ministry in the mid 1030s, certainly Burnett, as Deputy Chief of the Air Staff (DCAS), didn't appreciate the finer points of the two.
A zone fighter required a high rate of climb to reach its patrol altitude as quickly as possible.
For interception fighter, speed and distance covered in a pursuit climb were important.
Clearly the two types would be optimised for these different roles. The confusion over the 'Fury replacement' seems to stem from this aircraft's switch from its original, intended role. The Fury was designed as interception fighter, but the 1931 air exercises showed that this system was unworkable and the Fury was withdrawn to the Air Fighting Zone to serve as a zone fighter.
Burnett put rate of climb as a priority for the new fighter to replace the Fury but the Director of Technical Development (DTD), Cave, did understand the issue. He asked whether this was to be at best climbing speed or that to give the quickest interception of an enemy at a given height and speed. The Air Ministry reply was that the climb requirement was for the best to 20,000ft. This small detail actually implied a significant change of policy, though I don't believe that the decision was made in the full understanding that this was the case.
Cheers
Steve
A zone fighter required a high rate of climb to reach its patrol altitude as quickly as possible.
For interception fighter, speed and distance covered in a pursuit climb were important.
Clearly the two types would be optimised for these different roles. The confusion over the 'Fury replacement' seems to stem from this aircraft's switch from its original, intended role. The Fury was designed as interception fighter, but the 1931 air exercises showed that this system was unworkable and the Fury was withdrawn to the Air Fighting Zone to serve as a zone fighter.
Burnett put rate of climb as a priority for the new fighter to replace the Fury but the Director of Technical Development (DTD), Cave, did understand the issue. He asked whether this was to be at best climbing speed or that to give the quickest interception of an enemy at a given height and speed. The Air Ministry reply was that the climb requirement was for the best to 20,000ft. This small detail actually implied a significant change of policy, though I don't believe that the decision was made in the full understanding that this was the case.
Cheers
Steve
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