Originally Posted by
BluSdUp
Vessbot:
I am still with You on the basic theory, BUT if unable to trim NU for any reason with a out of trim ND stab on the -800 you WILL run out of elevator if power is not reduced to control speed.
But again, if out of trim ND, as you’ve already agreed in another part, reducing the thrust will trim you further ND and exacerbate the problem.
And as a separate effect, the reduction in excess thrust (from zero to a negative value) will command a descent at the trimmed (now faster than before) speed. But, the one possible saving grace for the thrust reduction action, before the descent there will be a temporary speed reduction (that causes the lift reduction that in turn causes the beginning of the descent). But, I emphasize, it’s only temporary and my gut feeling says that it will be relatively small. How small? I don’t know, but I have serious doubts about it getting from 300-350 to the 230 that you posit as the bootstrap point for the rest of the trimming process back to normal.
A very illuminating sim experiment that I absolutely want to see, is to level the plane at 350 knots, trim hands off, cut out the stab, and without touching anything else slam the throttles back to see exactly what happens (magnitude and time) with the airspeed.