Don: Above FL350 the margin between a Mach 0.80 cruise and buffet onset is very small.
Flyboy: You mean you might get into the coffin corner, break up and die?!!!!!
3ME: As I recall, your only choice is to maintain perfect airspeed +/- zero knots and burn off some fuel which then gives you a razor thin margin to do something, but I just don't recall what....
Scorsch: "Coffin Corner" means that there is a small margin between minimum airspeed (above stall) and maximum Mach number before buffeting starts. The AOA range of wings of airliners is fairly small at higher Mach numbers. The coffin corner normally is no issue when factoring in the safety margins, which is a 30% margin versus stall (Vmin = 1.3 Vs1g and CLmax = 1.3*CZmax_buffet).
The notorious coffin corner aircraft was the U-2 by the way. Ask Gary Powers.
10-4
I wasn't clear that I was trying to QUOTE what the mixed up "break up and die" guy was WRONGLY saying back on AD.com. Something like: "If you get to coffin corner and do anything, you break up and die"
It was funny- not that he was wrong, but 1) that he was so PASSIONATELY wrong, and also 2) that he was a TINY bit correct:
1) Exceeding the maximum speed/getting supersonic can cause a rearward shift in the center of lift, causing a nose-down pitch and potential further speed increases...in SOME cases, with SOME aircraft, this can be an unrecoverable situation and you break up and die.
2) Stalling COULD in SOME instances with SOME aircraft
a. Get you a flame out, or nasty spin and you break up and die.
b. Get you out of whack so you nose over, speed up too much, have the lift-shift, dive, break up and die.
3) Gary Powers and others found that "busting" coffin corner caused scary, unplesant losses of control, but NOT a GUARANTEED "break up and die" nor are you totally helpless if you reach coffin corner.
Back on AD.com, I think the guy said, that the only thing you could do is fly perfectly at coffin corner and burn off fuel and THEN you might GENTLY power back and descend with razor-thin margins.
Yeah, he was wrong, but I think he had it in his head that Vne was something defined totally by the plane being structurally stressed to the breaking point- thus his concept was that any change whatsoever, including throttling back would break the plane since it added a "force" to something "stressed to the max".
Repeating- I'm JUST TELLING THIS STORY FOR GRINS- I don't agree with what the dude said.