Hi Angus,
>Scratching my head here:confused:
Sorry, I guess that's my fault! I'll try to be more accurate now :-)
>Ok, so Willy modded the original Handly Page mechanism so that the slats would deploy relevantly to stall condition at any speed, not just the slow speeds. Am I understanding right?
The original mechanism were free-moving slats. The initial Me 109 design had an additional locking mechanism that did not allow the slats to come out of the wing unless 10° or more of flaps were deployed. This had nothing to do with the flap design, but it was old-fashioned mechanics.
(As I read about the SM79 having a similar mechanism, that might have been common practice then.)
In 1936, Messerschmitt considered the option of leaving the slats free throughout the entire flight envelope. That was apparently not common practice, at least not for high-performance planes, as intensive research was required. Gustav Lachmann of Handley-Page's contributed, obviously tackling the problem of high speed flight for the first time, too.
(Lachmann suggested a pneumatic emergency retraction for the slats in case they should induce an irrecoverable spin. Only during the trials it became clear that they actually made spins less likely and helped with recovery.)
>So, they still worked at slow speeds right, just no particular upper limit?
No, just no mechanical downlock anymore. The slats are not triggered by speed, even though it's often presented that way in books and on the internet. They are triggered by the airstream dependend on angle-of-attack (you could also say dependend on lift coefficient, because AOA and Cl are connected), so they'll come out at high speed in a high-G turn just the same as at slow speed in 1 G flight.
>So you're saying that both the F86 and the F4 had the Messerchmitt mod rather than the original?
Well, Messerschmitt didn't actually change the slats, he merely was the first (as it looks) to use them on a high-speed aircraft. As far as I know, the F-86 and the F-4 had the same type of slat as the Me 109, which basically was what Lachmann invented at Handley-Page in 1919.
>Eager to learn, always, and not immune to mistakes, so sorry if I misunderstand.
Probably I mis-explained :-) Sorry for that!
Regards,
Henning (HoHun)
