A Critical Analysis of the RAF Air Superiority Campaign in India, Burma and Malaya in 1941-45

[wuzak]

The Hotspur had its radiator in that position and was faster. The production P-40 as opposed to the prototype moved the radiator and was faster. I disagreed with your suggestion that it would be a better Hurricane than the Hurricane.

The nose position of the radiator does not necessarily mean better performance.

If it was that simple, why wouldn't they move the Hurricane's radiator to the nose?

And the Hotspur was faster than the Defiant? Maybe that was due to other factors than the radiator?

The prototype P-40's belly radiator was badly designed. That's why it was moved. Not sure they even did proper performance tests with the original radiator design before changing it.

 

[Kevin J]

"The aircraft would have been powered by the 1,260hp Rolls-Royce Merlin XX engine, which was expected to give it a top speed of 380mph at 23,500ft. "

Wow if that was even close to true it sounds like it might have been a useful addition to the fleet so to speak, instead of making all those Hurricanes. I guess they saw it as competitor to the Spit so they nixed it.

Maybe 330 / 340 mph tops when armed. You could add 35 mph to a Spitfire if you cleaned it up and removed all the bits that made it a usable fighter.

 

[Kevin J]

The nose position of the radiator does not necessarily mean better performance.

If it was that simple, why wouldn't they move the Hurricane's radiator to the nose?

And the Hotspur was faster than the Defiant? Maybe that was due to other factors than the radiator?

The prototype P-40's belly radiator was badly designed. That's why it was moved. Not sure they even did proper performance tests with the original radiator design before changing it.

Perhaps if the radiator is under the nose you affect view for deflection shooting and buggar up the c.g.

 

[Hop]

My guess is that the tropical filter has been removed as top speed is stated as 365 mph and Rolls Royce has recommended or prevented the use of override boost.

The test notes say it was tropicalised, the statement on the condition of the aircraft makes no mention of the filter being removed. They also say "during the tests the engine limitations as stated in the handbook were adopted". I suspect they were simply using an original handbook, rather than the updated version authorising higher boost limits.

 

[Shortround6]

"The aircraft would have been powered by the 1,260hp Rolls-Royce Merlin XX engine, which was expected to give it a top speed of 380mph at 23,500ft. "

Wow if that was even close to true it sounds like it might have been a useful addition to the fleet so to speak, instead of making all those Hurricanes. I guess they saw it as competitor to the Spit so they nixed it.

It wasn't even close to being true, any more than the Typhoon was a 460mph airplane or the Beaufighter was a 370-380mph airplane.

Instead of thinking that the Spitfire had "the fix" going on in procurement why doesn't anybody wonder what kind of blackmail evidence Boulton Paul had that required the manufacture of hundreds of Defiants well after it was shown they were near useless as combat aircraft

The Defiant I had been test both with and without turret (with ballast) so they knew exactly how much extra drag the turret caused. changing the engine wasn't going to change that and in fact the larger radiator (poorly designed) cut into the expected performance of the MK II Defiant.

 

[Schweik]

As usual, words are being put into my proverbial mouth. I never said the Spit or Supermarine 'had the fix', I was just quoting the linked article which suggested that the turretless defiant was considered redundant because it was equivalent to the newer models of the Spitfire. My interpretation of this remark is that they didn't want to duplicate the effort.

As to whether the projected performance was realistic or included armor and the planned (very heavy) armament etc., I did not claim to know, in fact to the contrary I pointed out that I did not know and that the claim was not proven.

The fact that the Defiant was at least considered for use indicates to me that my intuition about the design wasn't entirely wrong. I can think of a lot of other potential issues with it though which may have blocked.

I agree that it is a mystery that the Defiant was still being produced as a turret fighter in 1941, though it is unclear if it may have had significant utility as a night fighter. The issue to me is if they could have come up with a better replacement for the Hurricane as a day fighter which was an excellent fighter in 1940, was clearly obsolete by the end of 1941 yet still being produced in large numbers in 1944. That is a bit of a mystery to me, and I think it cost the lives of a lot of Allied pilots.

Relevant to the thread, the hotly debated issue of whether the Hurricane was still providing useful service in Burma in 1944-45. I don't think it was based on what I have read. Same for the Med / Italy, where clearly it's utility had faded dramatically by 1943.

 

[Schweik]

View attachment 547141
from this site​

This photo seems to indicate that they did make a prototype, is that a Merlin XX? Does it have guns? (I don't see any) Did they do any flight testing of it?

 

[fubar57]

This is all I could find. The above photo is also seen in Mushroom Publications "Boulton Paul Defiant" and has this caption....

 

[Schweik]

Wow very interesting. So they did test it.

 

[Kevin J]

The test notes say it was tropicalised, the statement on the condition of the aircraft makes no mention of the filter being removed. They also say "during the tests the engine limitations as stated in the handbook were adopted". I suspect they were simply using an original handbook, rather than the updated version authorising higher boost limits.

There's no way that a Spitfire Vc with a volkes filter was ever going to do 365 mph, it's more like the 345 mph of the Seafire IIc. A Vc Merlin 46 SU carb did 368 so take off 8 - 10 for the standard version without filter. Seafire IIc did 320 at 16000. So maybe it was an Aero vee filter.

 

[fubar57]

I've got 354 @ 17,400 ft. from the book "Spitfire" by Tony Holmes

 

[Kevin J]

I've got 354 @ 17,400 ft. from the book "Spitfire" by Tony Holmes

That's a Vb Merlin 45 Volkes filter.

 

[fubar57]

Books says Vc Trop...

 

[Kevin J]

Books says Vc Trop...

View attachment 547219​

Merlin 45 not 46.

 

[Schweik]

Books says Vc Trop...

View attachment 547219​

Is that accurate speed for the MC 202 (including Tropical filters etc.)? If so, really quite a performance advantage (+18 mph at a slightly higher altitude) for the Macchi especially considering the Spit had a 295 hp edge...

 

[Kevin J]

Is that accurate speed for the MC 202 (including Tropical filters etc.)? If so, really quite a performance advantage (+18 mph at a slightly higher altitude) for the Macchi especially considering the Spit had a 295 hp edge...

Spitfire is 33% bigger with 3 X weight of fire. Macchi probably loses 11 mph with trop filter.

 

[fubar57]

From the book "Spitfire V vs. C.202 Folgore: Malta 1942

 

[Kevin J]

From the book "Spitfire V vs. C.202 Folgore: Malta 1942

View attachment 547220​

IIRC Early109G-2 did 384, with filter 373.

 

[Schweik]

If it was a choice between the cannon vs. 18 mph in speed and 6 minutes in climb rate to 20,000 feet instead of 8, I think I'd go with the lighter guns. At least for fighter vs. fighter combat.

 

[Kevin J]

If it was a choice between the cannon vs. 18 mph in speed and 6 minutes in climb rate to 20,000 feet instead of 8, I think I'd go with the lighter guns. At least for fighter vs. fighter combat.

So long as you're a good shot. The Soviets had 15100 Yak-1/7's and 10 pilots had 8 or more victories. They had 2600 Hurricane IIb/c's, 3 pilots with 8 or more victories. So the Hurricane was twice as effective in combat even though it was universally recognised as obsolete in the ETO. It did have twice as much firepower as a Yak.