Me 262 Air/Speed brakes

[Rivet]

Speed brakes became an active area of aerodynamic research in the Luftwaffe after the initial CIC, Wever, dying in an aborted take off of his He-70 and the succeeding CIC, Kesselring, assuming the formation of the Luftwaffe. The importance of all aircraft accepted as bomber, save for the dedicated horoziontal 111, meant the airframe must have the ability to deliver stores in some manner of diving flight. DVL, the research arm, formed it's own laboratory dedicated to the solution of problems, becoming a massive effort as the entity expanded its own research facility in Vienna after the Anschluss, and the projected speed of delivery increased.

Regarding the lack of speed brakes in the Messerschmitt 262. Yes, the 262 possessed one aerodynamic control which served as a brake, that of the moving tail. Rapid use of the tail served to adjust the line of flight relative to motion in order to utilize drag as a limiting mechanism. The mention of use of the automatic stores release mechanism in a post above should have this included in data.

Most of the larger bomber aircraft controls were body-panel foils included in aircraft as large as the Heinkel 177. Regards

[Gixxerman]

Interesting Rivet.
I must admit I always thought the variable incidence tail-planes was purely a trimming device albeit a major trimming device, as stores or armament was used or fuel was used up & the CoG changed during flight.

I had seen the Hans Guido Mutke claims before but always assumed that his success in slowing the plane down using the tail that way was one of last-ditch desperation rather than it being an accepted & known method of dumping excess speed?

(personally I do not believe the story, I think a 262 would break up long before it got to mach 0.95.....as many have said his story does fit in very well with a craft experiencing the severe troubles non-supersonic aircraft get into as they approach and exceed their mach limit, but which is still well before mach 1)

[tyrodtom]

I've read Mutke's account too. I took it to mean he used the trim to pull out of the dive, because his elevators were rigid. Pulling out of the dive slowed the aircraft down. Not the trim slowed the aircraft down, then he pulled out of the dive.

[Siegfried]

I've read Mutke's account too. I took it to mean he used the trim to pull out of the dive, because his elevators were rigid. Pulling out of the dive slowed the aircraft down. Not the trim slowed the aircraft down, then he pulled out of the dive.

The speed of sound at 36,000ft is 660mph, at sea level it is 750mph. Sooner or latter the air thickens, the aircraft may slows down and the mach limit of course goes up so that the mach tuck disappears.

Modern aircraft still have mach tuck, they simply have minimized it through sweep or thing wing sections and have the flight control system trim it out.

The Me 262 had quite a thin wing section and that 18 degree sweep would have raised critical mach up to 5%.

I believe the all trimming tail plane had a too weak electric motor.

One problem with using such an all trimming system is that when the mach tuck disappears the aircraft may be pulling out with very high g, I believe this is why the P-38 disintegrated during dive tests.

The British solution on the Miles M.52 was simply to move the whole tail surface.

The Germans were inclined to use wing sweep to maintain subsonic conditions and behaviour, use elevons (Focke Wulf TA 183, Messerschmitt P.1112), with a t-tail out of the slip stream only for trimming.