Salute!
From
Bill
If I understand correctly MCAS is a sub-system designsd solely to counteract the lift generated by the engine nacelles at higher than normal AOT........
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Why did they not simply alter the elevator feel circuit so that higher force was required to pull back on the stick, sorry column if the AOT was too high and the stick forces were reducing due to the nacelle lift
The problem, Bill, et al, is that the plane required an aerodynamic fix for pitch moments approaching the stall AoA. Sure, in noirmal, non-FBW systems you would expect increasing back force to increase AoA. The new motor mount and such resulted in less back force per each increase in AoA - aero force, not the artificial feel sustem they already had. A pure cable system with no "help" would have made that very obvious for most of us here, especially those with lottsa light plane time. So Boeing figured they would just crank the stab to generate more nose down pitch moment, and the existing feel and such would take care of everything else, huh?
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- Make the sucker nose heavy and use a single AoA vane to trigger it. Don't sweat a FUBAR vane, as the stick shaker would prolly be going off and provide a clue that something wasn't right
- Let her rip for almost ten seconds and 2.x units nose down, then wait 5 seconds and do it again.
- Don't look at airspeed, just flaps and autopilot settings besides the AoA vane
- To disable the doofer, simply turn off all the electric trim to the stab. Neat, huh? Oh, you lose the yoke trim Gums! No biggie, we can crank that little wheel 50 times. Just don't get fast.
- Yeah that's it. And let's increase the authority of MCAS a bit to be on the "safe" side and don't advertise this, as it might require a sim ride or something.
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And finally today's comment:
@ driver. The first crew call I can see about AoA vane is about 4 minutes from WoW. It could be that at that point they turned the electric trim back on.. at 43:11 we see manual trim from yoke, and sure enuf, 5 seconds later we see MCAS crank the trim down to 1.0 from 2.3 units and they were doomed.
Gums sends...