The hated and feared autotrim, or not
Have been on the sideline too long watching defense of a poor control law reversion sequence versus a defense of a poor crew.
Gums' view is there is a lotta blame to spread about.
Take the auto trim, and I do not like that term.....
- When normally flying the jet, HAL tries to reduce required stick displacement from neutral in order to achieve 1 gee that is corrected for pitch. So at 30 degrees pitch, the thing tries to achieve 0.87 gee with hands-off the stick. If I don't read that part of the manual correctly, lemme know.
- If the pilot is commanding more than one gee ( corrected for pitch), then HAL trims the THS to reduce the required stick displacement, or am I wrong on that as well? I see no AoA command when looking at the manuals, but I see some "protections" and warnings that hinge upon AoA.
- If I am at a 15 degree pitch attitude and let go of the stick, then what does HAL do to maintain 0.96 gee as my speed decreases? Does HAL trim the THS for more nose up?
- Then there's AoA sensors that are ignored because the speed is below 60 knots. So how is the stall warning considered valid when the AoA was being ignored? What the hell are you going to use if airspeed indications are unreliable? Maybe replace all the stuff on the LCD screen with a crosshair and dot, then tell the crew to "center the do"t, huh? BEAM ME UP!
Deeply stalled, deep stall, just plain stalled..............
In a plane with a super wing design and great directional stability, then it is easy to be stalled and not spin or have severe wing rock. Buffet could be very low and/or masked by the local weather conditions.
I do not defend the AF crew for the continuous nose up commands, but I can understand the confusion once the jet was "deeply" stalled and various warnings were being presented.
The facts now present clear proof that one can stall the 'bus without going into a spin or having severe wing rock or buffet. Anyone disagree?
The facts do not show that a recovery from the flight condition I just mentioned is impossible, especially with a fully trimmed THS.
Show us the pitch moment versus AoA/CG graph.
I only joined this discussion because I had FBW experience way before the 'bus and was interested in the plane. I also thot I could add perspective from lessons-learned 15 years before the A320 flew.
If I am off base here, or considered a dinosaur that still insists upon mechanical feedback to my stick or wheel or yoke, then tell me to stay quiet.