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3. Who had a simulator that simulated MCAS upset? 4. Which is not at all what happens with runaway trim. Also runaway trim that pilots are trained on is a cons
by cmurf 7y ago
3. Who had a simulator that simulated MCAS upset?
4. Which is not at all what happens with runaway trim. Also runaway trim that pilots are trained on is a consistent and relatively slow trim. The MCAS upset form is intermittant, and can be but isn't always, aggressive and comes with a ton of other data in the form of various instrumentation disagree warnings and possibly stick shaker going off which NEVER happens in a runaway trim situation.
6. Boeing's design and US-centric expectation of pilots didn't prevent US Air 427 from crashing. Literally everyone in the world expects pilots won't pull back on the yoke at stall. Yet these U.S. pilots did that. Colgan Air 3407, same thing, captain pulled back on the yoke during a stall making the stall worse, recovery impossible. Both accidents, each pilot had more than 1500 hours experience.
In US Air 427, the pilots aren't centrally blamed because the failure mode was a) caused by an airplane defect, a servo failure, b) the airplane's subsequent behavior was so abrupt and aggressive that the startle factor was pretty much not that surprising.
So why is it that the standard should be different for ET302 in particular? But also LNI043 and LNI610? Why would the blame not centrally be on Boeing even if the pilots made some mistakes, just like U.S. pilots have also made some mistakes yet weren't blamed as the proximate cause? And what mistakes did ET302 pilots make other than trusting electric trim being reenabled wouldn't immediately try to murder them?
- mlyle 7y ago> And what mistakes did ET302 pilots make other than trusting electric trim being reenabled wouldn't immediately try to murder them? Like I told you before: overspeeding the plane, preventing them from restoring the trim condition with the trim wheel. I get that if you're not climbing as much as you'd like, it's tempting to have a ton of power in. But the maximum airspeed of the plane is chosen because there are undesirable handling characteristics -- like not being able to manually retrim, or even worse things like aileron reversal-- above it. At some point you need to pull back power. If you're out of trim because of electric trim misbehaving, turning electric trim back on may not be the smartest thing, too. And then I can't even understand what happens next: if you touch the trim switch, MCAS can't do stuff for awhile. If they're going to re-enable electric trim, why didn't they then fully fix trim with the trim switch? How is MCAS able to actuate and worsen the existing out of trim condition?
- cmurf 7y agoRunaway trim checklist doesn't call for a power reduction. A power reduction for transport category airplanes always causes a nose drop, a requirement of certification . Attitude for ET 302 was already too low, further altitude loss isn't acceptable. Manual trim was jammed. 20+ degree down angle inside of three seconds. The negative G sent them to the roof. I'm a certified fight instructor, and I've never experienced negative G. MCAS killed them.
- mlyle 7y ago> Runaway trim checklist doesn't call for a power reduction. No, but overspeed does. > A power reduction for transport category airplanes always causes a nose drop a requirement of certification Please cite. If you point to 25.173/25.175, note that it refers to trim speeds and return to trim speed, not power. The plane was climbing before crossing Vmo / power could be reduced to maintain Vmo and the current climb rate. > I'm a certified fight instructor, and I've never experienced negative G. What? You've earned a spin endorsement, then. You've experienced the little negative G (in most planes) as you tip and enter the incipient spin. It's fun. The first time I did it I said "oh shit" and let go of the yoke to grab my seat. :P Also kinda alarms me that if you're an instructor you've never pushed a little negative.
- mlyle 7y ago> Boeing's design and US-centric expectation of pilots didn't prevent US Air 427 from crashing. Literally everyone in the world expects pilots won't pull back on the yoke at stall. Yet these U.S. pilots did that. The reason that '427 pilots aren't blamed is that it's unclear that with perfect inputs that the plane was recoverable. We also excuse them a bit because the situation became unrecoverable in a matter of seconds since it manifested, instead of a longer time with the MCAS upsets.