Originally Posted by
johnwick
Easy there Charles Lindbergh, I’m sure they were trying to trim. But in the 737 (maybe other aircraft), if you are applying significant force on the yoke in the opposite direction of the trimmed condition (ie nose down trim and pulling back very hard on the yoke), the trim wheel is very difficult, if not impossible to move without releasing the back pressure in this instance. I’ve flown a variety of aircraft in my life, and I’m not aware of any other aircraft to which releasing the pressure on the yoke/stick was a requirement to move the trim. I suppose if you’ve flown the 737 you’re entire life, you’d be aware of it. But its not instinctual or natural. And maybe they thought that putting the AP on would help the out-of-trim situation, as it has its own servo. JMO
They were not trimming, except for the Lion Air Captain, he was without difficulty; the FDR clearly shows that. Yes, the trim wheel is hard to move under high aerodynamic loads but guess what? They didn't need to use the trim wheel, the main electric trim was functional and trimming out a nose down condition (trimming nose up) while pulling back is not only natural, but quite easy. The main electric trim was available the entire time for Lion Air and available up till the time turned it off for Ethiopian. If Ethiopian had followed either of the checklists they were told to run in the AD they would not have needed to use the trim wheel. The trim wheel is also a little hard to use when you are going 420 knots. That is well beyond the operational envelope of the aircraft. Never bothering to even touch the throttles during a flight will do that.