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Soren, that site had the very manual I was referring to. (with the comment of no functioning trim tabs) Accordingly, all trim changes for pitch are made by adjusting the horizontal stabilizer.
(the article also mentions the aileron tabs being intended to be of the in flight adjustable servo type, but were simple ground adjusted tabs in practice)As is the case with several other German planes, the 262's all metal stabilizer is adjustable, the incidence being changed by a small electric motor operating a screw jack mounted inside the fin fairing on the front face of the frame to which the vertical fin is bolted. This unit is
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mass-balanced trim tabs set near the inboard end. These tabs were apparently designed as interchangeable servo units, for a small arm at the outboard end extends up from the right one and down from the left, and captured enemy documents show an anchoring arm designed into the stabilizer trailing edge. However,the operational experience or Allied bombing made completion of this plan impossible, for the tab arms were not connected to the stabilizer and, in fact, the tabs had been riveted into immobility by small gusset plates at each end. Nevertheless, each tab had four hinges, with ball bearing units at each end and pins through yokes forthe two in the middle. As is the case with the rudder trim tab, the trailing edges of the tabs are nicely flush riveted..
Don't forget also the Miles 'Gillette Falcon', the first aircraft in the world to use an all-flying tail specifically intended for control at high speeds. It flew in 1944 and was built specifically in response to the need to be able to control the Miles M.52 at supersonic speeds. It is recognised that without this device Yaegers attack on the sound barrier in the X-1 could not have been successful so yes, the British were quite well up on this asp0ect of controllability at the time.
Acknowledge ? Bill I've never claimed there weren't any, I just pointed out that the entire horizontal stabilizer was used for trim, esp. in cases where the trim tabs weren't enough. (The Bf-109 had the same feature, which is what allowed it to recover from high speed dives quicker than other fighters)
And I pointed out the two possible conditions which would cause a nose down tuck - both involving some degree of issue with the elevator at compressibility range - and you have not pontificated on the 'final word' on that question..
The only way to get out of the negative G dive the Me-262 would start after 1,100 km/h was to utilize the movable horizontal stabilizer, the elevators and therefore also trim tabs being rendered useless because of turbulent flow.
Lol - you wish to claim that the 262 reached 1100KM/hr BEFORE compressibility started? You know that is about 593 kts and at SL = .89 Mach and 593 kts~ 95. Mach at 15000 feet, and .98M at 25000ft - at STP?
At what altitude do you propose the 262 ever came close to 1100km/hour? and that Mach number would Be?
I believe one of the riveted gusset plates is visible in this immage:
Look closely at the inboard trailing edge of the tab on the right.
Bill the airspeed indicator went off the scale at 1,100 km/h at 36,000 ft, at which altitude the speed of sound is 1,062 km/h. Mutke notes that heavy vibrations started around that time and the a/c started to nose down uncontrollably, until suddenly the vibrations stopped. Mutke then started to recover the dive by shutting the engines and trimming the movable horizontal tail plane, and while pulling up the vibrations suddenly started again, but he managed to pull out and reduce the speed to 500 km/h.
I'm not saying the speed readings were accurate Bill, they were obviously too high when the vibrations started cause as noted the speed of sound is below 1,100 km/h at 36,000 ft. However all the characteristics he notes pretty much concludes he went supersonic, and like modern aerodynamical studies have shown it indeed is possible. So I have absolutely no reason not to believe he went supersonic, other than your unsupported claim that he didn't based on a simple hunch.
the problem with wikipedia that all can write and can write that some it's take from a source
A computer based performance analysis of the Me 262, carried out in 1999 at the Munich Technical University, has shown that the Me 262 could exceed Mach 1.
The few originals (less than 10 worldwide) that still exist are now cloistered in museums, never to fly again. They are so rare and so valuable that to risk them in their natural element is considered by many to be nothing short of foolhardy. None are even close to being in airworthy condition. To see an Me 262 streaking through the sky again would seem to be a daydream ... until now!
If the issue was not turbulent flow but compressibility initiation over the elevator, the movable and boosted 262 elevator would have worked fine.
The comment on wing sweep on the wikipedia quote really has nothing to do with it. The advantage of sweep in the transsonic region being that the chord of the wing is phisically increased by sweeping the wing back (or foreward) to the extent that the COS of the sweep angle muliplied by the original thickness/chord will give the "real" thickness/chord. However, a thin, straight wing will work just as well for this purpose. (hence the Bell X-1, Douglass Skystreak, F-94C, CF-100, etc)
KK- the purpose of the sweep is to reduce the freestream airflow to a normal (chord wise) and transverse (spanwise) flow. By virtue of the sweep, the chordwise flow vector is reduced to the Cos of the sweep angle At The 1/4 Chord - not the leading edge. You can see that the effect is to significantly delay the transonic occurance over the wing..
Now at supersonic speeds, swept back wings (or a Delta planform) have other advantages, but that's a different issue.
The primary value of sweep is delay of transonic shock wave to a higher freestream velocity than a straightwing planform would experience. For same airfoil and same thickness, the one that is swept would experience transonic transition at a higher velocity. It also brings stiffness issues, and rolling issues for no dihedral. There are fewer aeroelastic issues (in general) for a delta wing than the equivalent swept wing with same AR.
The huge benefit of the Delta wing is the very small shift in aerodynamic center moving from subsonic to supersonic flight
Bill, I agree that the control problems on the Me 262 should start to manifest at a TAS of ~914 km/h (568 mph/494 kt) at ~36,000 ft. I'm not entirely sure Soren was implying that the airspeed indicated on the Me 262 was close to the TAS, I think it may be another case of misenterpretation.
Soren, could you clarify what you meant by the 1,100 km/h figure? (did you simply mean that this was the indicated speed when the control problems occured?)