No Spitfire?

[Admiral Beez]

Supermarine was a small company it could design the Spitfire but didn't have the people to make it, but in 1936 who did?

That was my point, positing that Supermarine could not have made the Hurricane.

Vulture development was also paused during the BoB, as was the Peregrine, Exe and Crecy. The Vulture, Peregrine and Exe were cancelled shortly after.

IMO, RR needs only two engines in WW2; the Merlin and the Derwent. The Griffon would be missed, but the rest can be scrapped.

 

[Shortround6]

first flight Oct 6th 1939. Design work had started in 1937.
The Griffon would have been looked upon as a 1/2 step, not an ultimate destination.

In 1939 1760 were ordered from Avro and 200 from Cunliffe-Owen. This aircraft and it's sister Typhoon are the dark clouds hanging over any alternative British fighters in 1938-39-40.
Why fool around with 1500-1600hp engines (early Griffon) when you have 2000hp engines on offer.
Why spend time fooling about with a Merlin powered aircraft when the big engines were right around the corner?

 

[Shortround6]

1 Defiant/P.94 showed good production tolerances, flush riveting, no gaps, nice cowling, wing fillets. The advantages of fully covered wheels have more impact than a tail wheel in the breeze (non retractable tail wheel is something that Spitfire had as well). The Defiant/P.94 would have had non of the disadvantages of the Hurricane except a thickish wing but it was at least of advanced NACA type. It had advantages of high tolerance production. The fully covered main wheels probably have as much impact on speed as a thick wings.

The Defiant/P.94 showed no such things because there was NO P.94 ever built.
The 'demonstrator' and subject of the all the pictures was the original P.82 Defiant prototype which was rolled out in 1937 and first flown Aug 11th 1937, it may very well have displayed good or excellent workmanship. It made a number of flights before the turret was fitted. The turret was installed and later removed. The performance with the turret removed was used to estimate the performance of the P.94 but the aircraft (K8310) was never fitted with the proposed Merlin XX engine. The Defiant II when fitted with Merlin XX showed only a very modest increase in performance. In part due to additional operational equipment. In part due to larger radiator and oil cooler. Perhaps in part to different surface finish (night fighter black?). But somehow the idea persist that by pulling the turret the Defiant would have gained around 40mph. The original Defiant showed no such speed change with and with out turret. At least nobody remarked on or recorded such a speed change. The P.94 was supposed to be an emergency fighter making as much use of existing Defiant tooling as possible, There was no short fuselage, clipped wing, lightened structure version. Hurricane II was about 20mph faster than a Defiant II using the same engine. Hurricane I was about 15mph faster than a Defiant I using the same engine. Yanking the turret and plating over the hole might get close or even equal the Hurricane, but to fly more than a few mph faster?
BTW the K8310 was never flown with holes in the wings for machineguns or slots in the bottom of the wing for ejected cartridges and links. No gun bay hatches or ammo hatches/boxes/ access panels.

Not sure where the conviction about the covered main wheels comes from. my own opinion is that it might vary with the particular aircraft. Curtiss P-40s lost the wheel coverings the P-36 used, Curtiss should have known exactly what the speed loss would have been for their landing gear design/wheel wells and covers. The P-40Qs still had open wheel wells and the one attempt to use it as a race plane still had open wheel wheels. Some planes did benefit from added doors but how much each design did benefit may not be the same.
Local airflow may vary a bit from design to design.

 

[wuzak]

Not sure where the conviction about the covered main wheels comes from. my own opinion is that it might vary with the particular aircraft. Curtiss P-40s lost the wheel coverings the P-36 used, Curtiss should have known exactly what the speed loss would have been for their landing gear design/wheel wells and covers. The P-40Qs still had open wheel wells and the one attempt to use it as a race plane still had open wheel wheels. Some planes did benefit from added doors but how much each design did benefit may not be the same.
Local airflow may vary a bit from design to design.

The Spitfire prototype had full undercarriage fairings, but the design had some issues with clogging up on grass airfields, I believe. The covers were mounted on the undercarriage legs with the end part hinged up when the landing gear was down.

Comparisons were done with and without the full covering, and it was found the difference was negligible. At least not enough to warrant keeping the fully enclosed main gear.

 

[GrauGeist]

Keep in mind that the P.94 was not going to have a "faired over" cavity in the fuselage, it was to have the fuselage modified to eliminate the turret framing, allowing for a clean line from the cockpit to the empennage.
This would both reduce some weight and clean up any drag penalty that the Defiant's turret base would have created.

 

[PAT303]

IMO, RR needs only two engines in WW2; the Merlin and the Derwent. The Griffon would be missed, but the rest can be scrapped.

In 1939-1941 the Whirlwind would have been a very handy aircraft to have, I don't know much about the peregrine but whirly birds booming and zooming He111's with 10-12 nose mounted .303's would have been decisive in the BoB.

 

[PAT303]

Keep in mind that the P.94 was not going to have a "faired over" cavity in the fuselage, it was to have the fuselage modified to eliminate the turret framing, allowing for a clean line from the cockpit to the empennage.
This would both reduce some weight and clean up any drag penalty that the Defiant's turret base would have created.

My argument in regards to the Hurri and P.94 is you are putting lipstick on a pig, the designs had no growth potential, re-engining them was not going to make them a war winner, no amount of power was going to get you a MkIX spit or P51B.

 

[Admiral Beez]

In 1939-1941 the Whirlwind would have been a very handy aircraft to have, I don't know much about the peregrine but whirly birds booming and zooming He111's with 10-12 nose mounted .303's would have been decisive in the BoB.

I'm a big Whirlwind fan, but the Peregrine is as much a dead-end for Roll Royce as their Vulture, Eagle, Exe and Crecy. It's Merlins (and Meteors for the Army) all the way to VE Day.

I'd have pulled Petter off the Whirlwind and had him design the FAA's single engine, monoplane fighter instead of the Fairey Fulmar. Ideally a single seater if the FAA and AM can be strong armed to abandon the two seater notion. Essentially an early, smaller Merlin-powered version of Petter's Westland Wyvern.

 

[pbehn]

View attachment 617889
View attachment 617890
first flight Oct 6th 1939. Design work had started in 1937.
The Griffon would have been looked upon as a 1/2 step, not an ultimate destination.

In 1939 1760 were ordered from Avro and 200 from Cunliffe-Owen. This aircraft and it's sister Typhoon are the dark clouds hanging over any alternative British fighters in 1938-39-40.
Why fool around with 1500-1600hp engines (early Griffon) when you have 2000hp engines on offer.
Why spend time fooling about with a Merlin powered aircraft when the big engines were right around the corner?

I know that was the logic but as it panned out they were going down a lot of blind alleys. The Whirlwind was ordered as a cannon armed fighter, but the Vulture engine was basically two Peregrins, so if the Whirlwind has the power to do the job so has the Tornado and Typhoon, the issue is getting cannons to work in wings, so work on that.
The swept volume of the Vulture isn't much more than the Griffon, but it has twice as much of almost everything, in terms of war production you will always be able to make and keep in service more Griffons than Vultures.

The Tornado/Typhoon were designed for 1750=2000 BHP engines, but even in 1938 RR were running experimental Merlin Engines at 1800BHP, engines didn't have to be that big, and from the start the Typhoon/Tornado were too big. The Sea Fury ended up about 1m less in wing span, its weight operating on mesh airfields in France was an issue.

 

[pbehn]

My argument in regards to the Hurri and P.94 is you are putting lipstick on a pig, the designs had no growth potential, re-engining them was not going to make them a war winner, no amount of power was going to get you a MkIX spit or P51B.

The Hurricane wasn't supposed to have any potential, as per S/R post both the Typhoon and Tornado were supposed to replace it and thousands of them were ordered, both types affected by problems of engine supply from the start.

 

[GrauGeist]

My argument in regards to the Hurri and P.94 is you are putting lipstick on a pig, the designs had no growth potential, re-engining them was not going to make them a war winner, no amount of power was going to get you a MkIX spit or P51B.

But this scenario revolves around no Spitfire. Meaning it didn't exist.

So what does Britain do in 1940?
Wait a few years for the Mustang to be designed and built? (Requires time-travel, though)
Purchase Curtiss P-36/P-40s?

Or explore the P.94 option since the Defiant prototype (when flown without the turret) was found to be faster and more maneuverable than the Hurricane but just slower than Spitfire (which doesn't exist in this scenario).

So the P.94 stands as a viable alternative.
Not sure why this is such an issue...

 

[Admiral Beez]

But this scenario revolves around no Spitfire. Meaning it didn't exist. So what does Britain do in 1940?

Easy, make more Hurricanes and Whirlwinds whilst expediting (as reasonably possible) the Sabre and Typhoon. I'd skip the Defiant and its possible derivatives and put those Merlins onto more Hurricanes.

By 1942 RAF Fighter Command is Typhoons, Hurricanes and Whirlwinds, plus Bomber Command Beaufighters and gun-armed Mosquitos.

 

[Shortround6]

I'd have pulled Petter off the Whirlwind and had him design the FAA's single engine, monoplane fighter instead of the Fairey Fulmar

The Fulmar, as has been said repeatedly, was an interim fighter, based off the P.4/34 light bomber. They took the 2nd prototype P.4/34 and modified it saving many, many months of work. Starting with a clean sheet of paper would have resulted in the hoped for single seat fighter fighter showing up in 1941 or later. The Fulmar showed up in 1940. Without the Fulmar the FAA would have been reduced to begging more Gladiators from the RAF for 1940 and early 1941 while they waited for the single seat wonder fighter to show up.

And be careful what you ask for, Petter may have decided that what the RN really needed was a single seat Lysander
Rugged, short/slow take-off and landing, a monoplane so it would be more advanced than the biplanes. Good view over the nose.

 

[wuzak]

I know that was the logic but as it panned out they were going down a lot of blind alleys. The Whirlwind was ordered as a cannon armed fighter, but the Vulture engine was basically two Peregrins, so if the Whirlwind has the power to do the job so has the Tornado and Typhoon, the issue is getting cannons to work in wings, so work on that.

Technically you could say that since the Vulture pre-dated the Peregrine that the Peregrine is half a Vulture.

The Vulture was rated for 3,200rpm (before con-rod issues), the Peregrine 3,000rpm.

The Vulture fitted to the Tornado was more than twice the power of the Peregrine. The Sabre for the Typhoon was more powerful than that, so they certainly would have no problem with the 4 cannons (as it proved historically).

The swept volume of the Vulture isn't much more than the Griffon, but it has twice as much of almost everything, in terms of war production you will always be able to make and keep in service more Griffons than Vultures.

2,592 cubic inches (42.5L) vs 2,240 cubic inches (36.7L). 15.7% greater capacity and 39% greater piston area. Which means more potential power for the Vulture.

 

[Shortround6]

So the P.94 stands as a viable alternative.
Not sure why this is such an issue...

Because the actual improvement of the P.94 over the Hurricane is rather debatable. Everybody is basing the performance off an estimate.
The difference in performance between the Defiant prototype with and without turret is nowhere near the performance needed to even get close to Spitfire performance.
As soon as you start mucking about the fuselage things can go south in a hurry. Plating over the hole (or a fancier version of that modification) ) requires adjusting the center of gravity. Done with ballast on the prototype? done by actually moving equipment on a production version or a combination of the two?
chopping 3 feet or so out of the rear fuselage does raise CG issues, it also changes the control moment.
"p. The pitching moment occurs about the center of gravity (CG). The strength of the pitching moment is determined by the distance between the CG and the horizontal tail surface, as well as by the aerodynamic effectiveness of the horizontal tail surface".

Shorten the fuselage and you may need larger horizontal and vertical stabilizers and/or different sized elevators and rudders. Or maybe you can get away with it. Might need a bit flight testing and tin bashing before committing to production though.

The K8310 was never fitted with forward firing guns, some accounts talk about a mock up of four machine guns. It never got the Merlin XX engine. Few, if any, performance numbers of actual test flights in this later arrangement seem to exist, in fact actual performance numbers as originally built without turret seem to be rather rare. Descriptions like "surprising good performance) show up but that doesn't actually say much.

Beating the Hurricane is not that high a bar.

 

[ThomasP]

On behalf of the Hurricane, I resent that.

 

[Shortround6]

2,592 cubic inches (42.5L) vs 2,240 cubic inches (36.7L). 15.7% greater capacity and 39% greater piston area. Which means more potential power for the Vulture.

Coupled with the higher rpm allowed by the smaller cylinders means higher power on the same fuel.

And that was part of the problem in 1937-38-39.
WHEN was the 100 octane fuel going to show up?
How much would it cost/how much could they make?
What would the actual performance increase be?

They knew it was coming but those little details were still unknown and needed to allowed for. Betting everything on the smaller engine and hoping the better fuel shows up on time is a risky bet.

 

[Admiral Beez]

The Fulmar, as has been said repeatedly, was an interim fighter, based off the P.4/34 light bomber.

Certainly right. But the Fulmar was a necessity due to lack of alternatives. Petter, if through the lack of Whirlwind is given time and focus he'll put something forward to challenge the P.4/34 and Fulmar's necessity.

And be careful what you ask for, Petter may have decided that what the RN really needed was a single seat Lysander

I assume Petter, Fairey, Camm, etc, would make to the spec rather than tell the FAA what they need. Though the Westland P.12 Wendover is terrifyingly terrible.

 

[GrauGeist]

The Hurricane Mk.II was good for a top speed of 340mph and the Defiant Mk.I (with the Merlin III) was good for 304mph at a comparable altitude.

Now I'm going to go out on a limb here, and suggest the British may have been smart enough to do something with the P.94 to make it work, eapecially when war clouds were looming and they needed to up their game.

The Whirlwind was proving to be troublesome, they couldn't wait for the Typhoon's development and they had a solid option before them.
Sure, make more Hurricanes, but if Boulton-Paul had an assembly line ready aircraft, then why not?

 

[Shortround6]

The Hurricane Mk.II was good for a top speed of 340mph and the Defiant Mk.I (with the Merlin III) was good for 304mph at a comparable altitude.

And the Defiant II with the same engine as the Hurricane II could not break 320mph.
The Defiant I was 10-14mph slower than a Hurricane I with the same engine.
Getting 10-20mph by getting rid of the turret might be quite possible. But that only gets you to Hurricane performance, not better than Hurricane.
The Spit was roughly 30-35mph faster than the Hurricane with equivalent engines.

Can the single seat Defiant even split the difference?
If not.........why bother.