mach and stall
Thx, PJ, good review.
Gotta admit, that after a few years in straight wing planes I was then spoiled by sturdy subsonic wings and true supersonic wings. My straight wing jets "stalled" as you and the experts state. The shock waves over the wings caused by just a slight increase of AoA did more than cause the wing to lose lift, like the phenomena I described - aileron reversal, elevator reversal, etc. Scary, but I learned not to press the 'envelope" after some hairy moments.
THE RELEVANT POINT is if the crew tried to stop the "overspeed" warning by pulling up to slow down, then they could have entered a stall that they had not anticipated, way before speed was a factor. My training was to reduce power first, as pulling up got one closer to a stall and/or had other bad effects.
MY SECOND RELEVANT POINT ( IMHO) is that one can zoom at a comfortable AoA and gee and then run outta air molecules over the wing very quickly. By the time your AoA "protection" triggers, you are too slow for effective nose down control authority depending upon pitch moments determined by c.g. and basic aero characteristics of the jet. Back in 1979 we couldn't believe it would happen to our little rascal, but it did! It's why I joined the fray here when I saw more and more details of the crash. I simply wanted to point out that there are situations that the engineers never anticipated, whether "clever" maneuvers by the humans, or assumptions that the engineers made in the basic control laws.
Give me a 'bus and I believe I can duplicate the scenario easily. It is EXACTLY the scenario we discovered. Sure, pitch attitudes much lower, AoA much lower, but the identical scenario.
I pray that the users look at training, and remember the incidents of pitot-static failures.
And to beat a dead horse, I question the lack of design to allow for loss of the air data and still have a flyable jet. It ain't rocket science. Use last reliable data or use generic values depending upon gear up or gear down, etc. The Shuttle doesn't/didn't use air data until way slow. It was body rates, gee and such. The FBW systems use air data for "gains" - to command both rates and degree of control surface movement. Makes the jet "feel" like the old days, and it's a good thing. I would be the last pilot to recommend "direct" commands except as an absolute last-ditch maneuver. It's too easy to limit control surface movement according to "q". And body rates are easy to take into account without any air data at all. We only lost one jet I know of when the radome and pitot-static probes and AoA cones were ripped off. The guy flew for 10 minutes or more IFR (due to pelican blood over the canopy, heh heh). The body rates and 'standby gains" of the FLCS kept him flying on instruments until he gradually got into a PIO and had to bail.