Did the RAF have designs for a long range escort fighter?

The P-51 was a British plane outsource to North American.

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Just a few things about the P-51; it wasn't a British design; it was built for a British requirement for P-40s, which the British Purchasing Commission asked Curtiss for and were told to go see NA to build them for the Brits under licence. Kindleberger famously said, "We can build you a better fighter than the P-40" and so the NA-73X was born.

Edgar Schmued, a German who had worked with Willie M.

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No, he did not. Schmued was German, but never worked for Messerschmitt. The team was led by Raymond Rice and Schmued, but wasn't "German".

Edgar Schmued - Wikipedia, the free encyclopedia

"An urban legend has grown up about Edgar Schmued, possibly related to his German origins, claiming he had once worked for Willy Messerschmitt and that the Mustang was heavily influenced by the Messerschmitt Bf 109. Neither claim is true but the urban legend persists. Just as familiar is the notion that the abortive Curtiss XP-46 was the basis of the P-51 design."

Admittedly from Wiki, but accurate nevertheless.

Don't forget that the Mustang was not originally conceived as a high altitude, long range escort and that it entered service with the RAF first - before the USAAF got their hands on them and even then only when they saw its excellent performance - as an Army Co-operation aircraft (British terminology for close support) working alongside P-40 Tomahawks out of Gatwick in late 1941. Up to twenty RAF squadrons fully or partially equipped with Allison engined Mustangs.

The initial idea that the Mustang should be fitted with a Merlin (specifically 60 Series two-speed, two stage supercharged variant designed for the high altitude pressurised Vickers Wellington Mk.VI and earmarked for Spitfires) came about in Britain after Rolls Royce liaison pilot Ronnie Harker flew the Mustang on 30 April 1942. His flight report stated that he thought;

"The point that strikes me is that a powerful and good engine like the Merlin 61, its performance should be outstanding as it is 35 mph faster than the Spitfire Mk.V"

It's worth noting that at this time Rolls had only experimented with fitting a 60 series Merlin to a Spitfire V airframe the first Merlin 61 Spitfire was still a few months from entering service; the real impetus for a Merlin 61 engined fighter came after the appearance of the Fw 190 in September 1941 as we all know, when Supermarine's put into place development of the HF.VII, F.VIII and the stop-gap Mk.V airframe fitted with a Merlin 61, the Mk.IX.

Regarding British long range fighters, the Hornet was probably the closest that officially the British came to an escort fighter; there was never any specification released that stipulated the need for one, but the Hornet had F.12/43 (OR.126) written around it as it was a private venture. Designed initially as a long range fighter to oppose Japanese fighters, according to De Havilland A/c since 1909 by A.J.Jackson, the Sea Hornet (built to N.5/44) was to be used as an escort; "A production order was then placed for the Royal Navy's first twin engined long range escort strike fighter, designated Sea Hornet F. Mk.20."

According to Wik, the Tempest V had a range of (2,462 km) with 90 gal (409 l) drop tanks.

Just a wee addition to my post. The myth about Schmued working for Messerschmitt and the P-51 being influenced by the Bf 109 comes directly from the aforementioned Ronnie Harker, who wrote in his test report on the Mustang the day after his test flight;

"This aircraft should prove itself a formidable low and mid altitude fighter. It closely resembles an Me 109F, probably due to its being designed by one of the Messerschmitt designers, who is now with the North American Aeroplane Co."

I think its a shame that the Allison V1710 never got the attention which it deserved for development. It was lighter, produced more hp per pound than the merlin did at low altitude, cheaper to produce and even reversible in rotation without additional parts. And all this from a very small company...at least until GM bought it. And even with the backing of General Motors, Allison was a pretty small division in comparison with Rolls Royce. Clearly, the US was far behind Europe in the design of mechanical multiple stage superchargers, preferring the turbocharger instead. What I like about the turbocharger is that it doesnt take horsepower to make horsepower, but its a plumbers nightmare.

US was ahead of all the world in development of 'multiple stage' superchargers, the 1st one was designed by Pratt Whitney and used aboard F4F-3. P&W have had the support by the Navy in their two-stage development. Another one was designed by same firm, and was 1st used aboard F4U, then aboard F6F and P-61. Nobody in Europe, apart from RR, was using two or more stages in their engines, prototypes aside.
The turbocharger indeed looks like plumber's nightmare.

buffnut453 said:

The only thing the RAF could have done differently was to envisage the need to obtain air superiority at long-range in the mid/late 1930s. That simply wasn't going to happen because nobody believed there was such a need. Look at the single engine designs that came out of that period (including Me109, Hurricane, Spitfire, P-36/P-40), none of which were viable long-range escort fighters.

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Yes and your dates are important. Assuming a complete doctrinal volte-face any potential long range escort would have had to be on the drawing board in the early 1930s,flying by the mid 30s,contemporary with the British and German examples you give. Even the P-36/40 is probably just too late.
Some here seem to have lost sight of the fact that the war in Europe began in 1939
Cheers
Steve

Readie said:

Howabout the Westland Welkin - Wikipedia, the free encyclopedia ?

There was the Mossie Beaufighter that fitted the 'heavy fighter' with long range specifications for escorting bombers deep into enemy territory.

Other than these, there was no British long range fighter available.
'The bomber will always get through' mantra stifled development.

Cheers
John

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I love the Welkin but the clue is in the name. It was built to a 1940 specification for a high altitude interceptor.

To have a long range escort in 1940,when the RAF/Luftwaffe realised that the bomber would not always get through and switched to night time bombing, it needs to be an early 30s design which makes both the Welkin and the other two and just about everything else being suggested in this thread too late.

Cheers

Steve

The thing was that NOBODY could design a single engine long range escort fighter for most of the 1930s.

The available power plants would not allow it.

This is one reason for all the twin engine fighters floating around at the beginning of the war.

The British especially had a problem in that they were a little late to the game with variable pitch propellers. Part of the problem can be seen comparing Spitfire take-off distances to clear a 50ft obstacle.

with the Fixed pitch prop it was 790 yds.
with a 2 pitch prop it was 490 yds
with a variable pitch prop it was 370 yds.

This is for a plane weigh about 6050lbs.

Please remember that the Merlin III (and earlier versions) was good for 880hp for take-off.

Adding even a few hundred pounds of fuel is going to affect take-off performance.

A P-51B with NO rear tank and a pair of 75 gallon drop tanks was carrying over 1900lbs of fuel and had an operational radius of about 450 miles.

Trying for a late 30s fighter with even 2/3 the amount of fuel is going to give performance problems. More powerful engines were promised but on 87 octane fuel those engines were large, heavy, and thirsty.

Shortround6 said:

The thing was that NOBODY could design a single engine long range escort fighter for most of the 1930s.

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Exactly,which is why,way back up near the beginning of the thread I said that the argument that such an aircraft was not technically feasible,propounded by the Air Staff in the early 30s did have some merit.

The Air Staff used the argument to back up their own doctrinal bias. They wanted bombers and lots of them. These men had lived through the slaughter of WWI and envisaged a scenario where a war could quickly be won,from the air,without the need for a single British or Commonwealth soldier to set foot on the European continent.

Who knows what might have been possible had more time,effort and money been put into developing a long range escort fighter,but it wasn't. You have to try and put yourself into the minds of those men,sitting in Whitehall,back in the 1930s. It is difficult not to colour modern opinion with hindsight.

Cheers
Steve

How about this design: Gloster F.9/37 - Wikipedia, the free encyclopedia
If not with Merlin XX maybe P&W R-1830?

aircro said:

How about this design: Gloster F.9/37 - Wikipedia, the free encyclopedia
If not with Merlin XX maybe P&W R-1830?

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Not without a total redesign. The Taurus engine used for those performance figures never went into production and the production engines only gave similar power at low altitudes even then had over heating problems.

Swapping in more powerful engines means adding hundreds of pounds (if not over 1000lbs) about as far forward as you can put it which would really screw up the center of gravity. Maybe you can add enough stuff to the rear of the plane, like lead weight ballast, to get it to fly right but it seems like a long shot.

The Climb to 28,000 feet (8,500 m): 19 min, 36 sec is a little bit lacking also. A captured 109E was supposed to climb to 30,000ft in 17min, 12 sec, A Hurricane I in 17min,30 seconds, A Hurricane II in 13min, 20 sec and a Spitfire I in 15min,42 sec.
The Gloster with it's prototype engines has a service ceiling (altitude at which it can climb 100fpm) of 30,000ft. The four fighters named have operational ceilings (altitude at which they can climb 500fpm) from 31,400ft to 34,900ft (the two Hurricanes are the extreme).

I did a little back of the envelope figuring and the powerplant weight for a Merlin P-51 was about 3565 lbs. Engine cowling, starter, oil system, fuel system etc. For that the 51B got 1380 take-off HP and 1210 hp at 25,800ft, the 51D got 1490hp for take off and 1370hp at 21,400ft. These are Military power, 61 in of boost.
For a P-40C the powerplant weighed 2847lbs (using the same fuel system weight as the Mustang) for which the Allison gave 1040hp for take-off and 1040hp at 15,000ft. At 25,000ft it was down to about 600hp.

It was not only better engines but the better fuel that allowed the single engine escort fighter to work. A bare R-R Vulture weighed 2450lbs (complete power plant weighs???) and while it offered 2000hp for take off it was only offering 1710hp at 15,000ft on 87 (?) octane with the original 2 speed supercharger.

I do believe it was possible for the RAF to develop longer ranged fighter aircraft with the technology they had in the mid to late 1930s. What was required was higher octane fuels which allowed higher boost on the superchargers and/or higher compression ratios on the engine itself. Both the Merlin and Allison engines were producing 1000 hp on pretty crappy gasoline as it were. TEL and other chemical blends would have allowed this, also allowing revised cam profiles and timing changes for the valvetrain. The addition of internal fuel tanks plus drop tanks would then be possible-the engines would have had the necessary hp to pull the aircraft off the ground. 100 and greater octane fuels were being promoted by James Doolittle who was working for Shell Oil at the time.

nuuumannn said:

Just a few things about the P-51; it wasn't a British design; it was built for a British requirement for P-40s, which the British Purchasing Commission asked Curtiss for and were told to go see NA to build them for the Brits under licence. Kindleberger famously said, "We can build you a better fighter than the P-40" and so the NA-73X was born.



No, he did not. Schmued was German, but never worked for Messerschmitt. The team was led by Raymond Rice and Schmued, but wasn't "German".

Edgar Schmued - Wikipedia, the free encyclopedia

"An urban legend has grown up about Edgar Schmued, possibly related to his German origins, claiming he had once worked for Willy Messerschmitt and that the Mustang was heavily influenced by the Messerschmitt Bf 109. Neither claim is true but the urban legend persists. Just as familiar is the notion that the abortive Curtiss XP-46 was the basis of the P-51 design."

Admittedly from Wiki, but accurate nevertheless.

Don't forget that the Mustang was not originally conceived as a high altitude, long range escort and that it entered service with the RAF first - before the USAAF got their hands on them and even then only when they saw its excellent performance - as an Army Co-operation aircraft (British terminology for close support) working alongside P-40 Tomahawks out of Gatwick in late 1941. Up to twenty RAF squadrons fully or partially equipped with Allison engined Mustangs.


The initial idea that the Mustang should be fitted with a Merlin (specifically 60 Series two-speed, two stage supercharged variant designed for the high altitude pressurised Vickers Wellington Mk.VI and earmarked for Spitfires) came about in Britain after Rolls Royce liaison pilot Ronnie Harker flew the Mustang on 30 April 1942. His flight report stated that he thought;

"The point that strikes me is that a powerful and good engine like the Merlin 61, its performance should be outstanding as it is 35 mph faster than the Spitfire Mk.V"

It's worth noting that at this time Rolls had only experimented with fitting a 60 series Merlin to a Spitfire V airframe the first Merlin 61 Spitfire was still a few months from entering service; the real impetus for a Merlin 61 engined fighter came after the appearance of the Fw 190 in September 1941 as we all know, when Supermarine's put into place development of the HF.VII, F.VIII and the stop-gap Mk.V airframe fitted with a Merlin 61, the Mk.IX. "

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The AAF design standards, particularly stress specs, use by North American were important to the P-51 in that the later-required fuel loads and hard points were better accommodated. As I recall, a later Mustang model was built to RAF standards with significantly improved performance.
My reference for Schmued would be Donald Miller who does rather exhaustive research.
But one purpose of posting is to test facts. What about the PBS story about Kindelberger having a ghost midnight shift of illegal Germans during development of the T-6?
When the Mustang was designed, the long range, air superiority fighter was impossibility according to the powers that be, particularly the bomber powers. That was IMO the primary reason the RAF did not consider the need.
While I argue for the feasibility of an earlier P-51-B, Merlin production was probable the most intractable pacing item for volume production.

Hi, SR6,

During what time frame the Vulture had such power levels? What would be the name of the variant?
An engine with 1710 HP at 15000 ft, while weighting, bare, 2450lbs, should not have the word 'only' attributed to the power, not if we talk about pre-1944 engines. I'm not convinced that 2 stage R-2800 would provide better performance to a fighter. That power looks as good as 1830 HP at 11500 ft the Typhoon had (here).

Hi Balljoint.

The AAF design standards, particularly stress specs, use by North American were important to the P-51 in that the later-required fuel loads and hard points were better accommodated. As I recall, a later Mustang model was built to RAF standards with significantly improved performance.

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I don't doubt AAF requirements were taken into consideration in designing the Mustang; it was, after all an American design by an American team. It's only natural that NA would want the USAAF to operate the type. As for a Mustang (P-51 was a USAAF designation and not officially used by the British) model built to RAF standards, which model Mustang was that?

Later Mustangs were certainly modified for RAF requirements, such as radio fit and in later Mustang IIIs (equivalent to the P-51C) a 'bubble' hood instead of the earlier bird cage one, but I don't recall a specific late model Mustang built especially for the RAF. The Mustang was actually designed for service with the RAF to begin with, as the RAF was its first customer. Experimental Mustangs were modified by Rolls Royce as test beds for the Merlin, but they were research aircraft only and were not meant for service use. Packard did the design work on the nose to take the Merlin installation.

What about the PBS story about Kindelberger having a ghost midnight shift of illegal Germans during development of the A-6?

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I take it you mean A-36? Can't say I've heard the story, were they production line workers or design team? There's a big difference.

Merlin production was probable the most intractable pacing item for volume production.

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While it's a grand idea, the issue would have been Merlin design rather than production. If the Mustang was to be fitted with the Merlin from early on, like you propose, it would have been something like a Merlin 45 or such like. Thing was, the British Purchasing Commission stipulated the Allison for the fighter for commonality with the Kittyhawks and Tomahawks already in RAF use.
The 'High Altitude' Merlin 60 came along slightly later and was intended for the Wellington VI. It was Lord Hives of Rolls who asked the question as to whether it was suitable for fitting to a Spitfire. To really take advantage of the Mustang's advanced airframe, the 60 Series Merlin was the only real option.

The 2 stage R-2800 had 1800hp at 15,500ft but that is in low gear, in high gear it had 1650 at 22,500ft. While the dry weight of the engines was about the same the R-2800 doesn't have around 600+ pounds of radiators/coolant. Of course it is fatter with more frontal area/drag.

Once Merlin XX series engines are allowed over 9lb boost it doesn't look so good for the Vulture. Granted it was several years after the Vulture's Heyday but 1480hp at 12,500 for 1000lbs lessof dry engine weight + much smaller radiators and propeller doesn't make the Vulture look good.

We are talking in the context of an escort fighter which means while the plane doesn't HAVE to be as good as the short range defender it should be close. 10% worse in both speed and climb won't cut it.
While altitudes did not go up as expected after the BoB the escort fighters do need to keep the defenders from getting positions 3-8,000ft above the bomber formations and diving down through them. The escort fighters WILL have to fight, at least somewhat at 25,000-30,000ft.

Balljoint said:

The AAF design standards, particularly stress specs, use by North American were important to the P-51 in that the later-required fuel loads and hard points were better accommodated. As I recall, a later Mustang model was built to RAF standards with significantly improved performance.

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That would be the H model.

Balljoint said:

When the Mustang was designed, the long range, air superiority fighter was impossibility according to the powers that be, particularly the bomber powers. That was IMO the primary reason the RAF did not consider the need.

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I am not sure about the situation when the Mustang was designed but a few years earlier the basic difference between the specifications that lead to the P-38 and the P-39 was that the specification that lead to the P-38 was supposed to have 2 hours of endurance at max cruise speed at altitude and the Specification that lead to the P-39 only needed 1 hour of endurance. Armament, speed and altitude were supposed to be the same. the Actual planes did diverge from the original specification but the fuel for that extra hour seems to have been just a little difficult to get into a single engine plane.

nuuumannn said:

Hi Balljoint.



I don't doubt AAF requirements were taken into consideration in designing the Mustang; it was, after all an American design by an American team. It's only natural that NA would want the USAAF to operate the type. As for a Mustang (P-51 was a USAAF designation and not officially used by the British) model built to RAF standards, which model Mustang was that?

Later Mustangs were certainly modified for RAF requirements, such as radio fit and in later Mustang IIIs (equivalent to the P-51C) a 'bubble' hood instead of the earlier bird cage one, but I don't recall a specific late model Mustang built especially for the RAF. The Mustang was actually designed for service with the RAF to begin with, as the RAF was its first customer. Experimental Mustangs were modified by Rolls Royce as test beds for the Merlin, but they were research aircraft only and were not meant for service use. Packard did the design work on the nose to take the Merlin installation.



I take it you mean A-36? Can't say I've heard the story, were they production line workers or design team? There's a big difference.

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The specific "A-6" was the T-6 Texan. As best I can recall they were workin on the design/prototype and were "skilled workers".

I already spoke of the Tempest adequated range. Was it unsuitable to high altitude combat?

As a slightly different question, how come the Americans produced long range fighters?

We've established that the belief existed among all the nations, including the Americans, that the bomber will always get through so why did they see the need for these longer ranged fighters? Or was it just pure chance that they were adaptable to taking more fuel?