Fastest WW2 Fighter plane

OK, I'm de-railing/hi-jacking this thread, but 30+ years ago I remember reading something in a (British) newspaper Sunday supplement about a proposal for a faster-than-sound turbo-prop design to take the speed record for piston engined aircraft. I could have sworn the same article mentioned the Dornier 635 as having been theoretically capable of breaking the sound barrier. So far as I know the Do. 635 never flew, so it is pure theory (as is the ludicrously low top speed quoted in Wikipedia), and the traditional design would have, presumably, been totally un-flyable at speeds over mach 1, but what does everyone else think?

 

The only way a propeller driven aircraft is going to exceed Mach 1 would be in a dive after the propeller had departed the aircraft from excessive forces, in other words, its not going to happen.

By default, the propeller - especially the prop tips - are traveling at a much greater speed than the airframe. As the prop tips enter the transonic regime, drag rises precipitously from the formation of shock waves, and prop efficiency drops dramatically. The transonic regime presents a barrier to propeller driven aircraft through which they cannot pass.

The recognized world speed record for turbo props is held by the Tu-114 at 541mph (0.73 Mach) set in 1960. The recognized world record for piston engined aircraft is held by the highly modified F8F Bearcat Rare Bear at 528 MPH set in 1989.

A fully instrumented Spitfire was flown in a dive by the RAE to about 0.91 Mach, but the propeller departed and one of the wings developed a rearward sweep of several degrees in the process (I need to find my reference for exact details).

There is good reason that the speed records for propeller aircraft are long standing. If they are ever broken in will only be incrementally.

 

Thanks mcoffee, I'm not an aviation engineer, and so it is interesting to learn more about the limitations of the prop. I do recall that the 1970s design (which was, I believe, only a mock-up at the time I read about it) had very strange looking props (like the Do. 335, it was a push-pull design - hence the article mentioning the 335 and 635) - multiple blades that curved and twisted on all 3 axis - they looked more like exotic egg-beaters than traditional prop blades!

However, and whilst I accept that any 1940s piston engined design would have serious (or catastrophic) problems as it approached Mach 1, with its massive power to weight ratio and the performance of the basic 335 (comparable to the TA-152), could the 635 have been not only the fastest (non-jet) aircraft of WWII, but possibly of all time if it had ever been built? Has anyone ever run any simulations to estimate 635 performance?

 

Just my own opinion here, I believe the absolute limits of propeller driven aircraft were probably reached in the ’50s with the three turboprop fighter/attack aircraft prototypes of the US. By that I mean "production capable" aircraft, not modified "one-offs". The Republic XF-84h (nicknamed the Thunderscreech), the Douglas XAD2 Sky Shark, and the North American A2J Super Savage. Here is an interesting article on the first, with links to the other two.

The claim of "fastest propeller driven aircraft" however goes to the highly modified F8F Bearcat which reached an official speed of 528 mph in 1989.

Goto:

Republic XF-84H - Wikipedia, the free encyclopedia

The limited production of the Dornier Do-335 "Arrow" was sub 500 mph, since the Do 335 recorded speeds upwards of 470 miles per hour with both engines and a respectable 350 miles per hour on a single engine. Its rate-of-climb was about 1,750 feet per minute. I doubt that the non-produced 635 would have been much better than those turboprops of the US in speed.

Forgot to add this short YouTube of the XF-84 Thunderscreech

Goto:

http://www.youtube.com/watch?v=ymtfgqfuyQs

The sound is greatly muffled for the show.

 

Found something interesting.


Ludwigslust aerial combat

 

I think the P-47 M was a little faster than the N as it weighed less without the extended wing. Top speed for the M was 473 mph and the N was 467 mph

 

I would think the D-40 model would have to be the definative model. Even though the M and N models were faster I think based on effectiveness in combat plus all the production improvements like the compressability flaps and simpler controls plus the later hi-activity props would make it my choice.
One of the problems with the early models was the thin "toothpick blades" it was origionally equiped with. In turns these props wouldn't grip the air very well and the heavy plane "mushed" in turns. This was improved as the various paddle blade props came into use.
The plane was also designed as a high altitude plane and was very manuverable over 25,000 feet. It definately had to make it's adversaries fight it's way through it's strengths and tactics. It's a tribute to it's versatility that it performed so well at low altitude as it came to be used later in the war. Definatly my fravorite plane.

 

According to Warren Bodie the P-38 L could make 421 mph at about 25,00 feet. If WEP was used it could make around 440 mph for about 5 mins. of combat.

 

Urban Drew shot down two 262's in one pass while flying a P-51.

 

I would say the #1 operational description would be KILLS. The ME 262 would have to be considered operational as it has a verified record. Next would be "missions". We know there were two P-80's in the Med and possibly 3 in Britain but as I understand it, the few missions they flew were to see how they stood up to operations in a forward base in a combat situation. I wouldn't consider this operational. The same could be said of the P-38 M Night fighter. It seems it flew before the end of the war but what were it's missions?

 

I think what some posters,myself included, are alluding to is that the Allies could have put some aircraft into service faster if they were inclined to throw something into production before it was ready. Germany did that sort of thing the Allies didn't.

 

the P-38M NF flew post war missions over China

 

That's certainly not the definition used by the US military. To illustrate with a modern example take a look at the XM-25 XM25 Individual Airburst Weapon System - Wikipedia, the free encyclopedia
5 have been deployed to Afghanistan and used there apparently to considerable effect. However the weapons is still the XM-25 and is not yet considered operational. By your definition the Maus may have been "operational" even though only two prototypes were built.