Citat:
Jag ska svara på din fråga och hoppas att du kan bemöta det på ett moget sätt.
Det konstiga med en jackscreew i ändläge är att om piloterna hade problem med MCAS så skulle de enligt Boeings bulletin stänga av stab trim.
Att jackscreew är i ändläget indikerar att piloterna inte stängde av stab trim så fort de fick indikation på att flygplanet uppförde sig oväntat och gjorde nos ned.
Lion 610 är fortfarande inte jämförbart i den meningen att i det fallet kände piloterna inte ens till MCAS existens och funktion.
Min tro är att de har kämpat mot MCAS trots att det inte hade behövts.
Det konstiga med en jackscreew i ändläge är att om piloterna hade problem med MCAS så skulle de enligt Boeings bulletin stänga av stab trim.
Att jackscreew är i ändläget indikerar att piloterna inte stängde av stab trim så fort de fick indikation på att flygplanet uppförde sig oväntat och gjorde nos ned.
Lion 610 är fortfarande inte jämförbart i den meningen att i det fallet kände piloterna inte ens till MCAS existens och funktion.
Min tro är att de har kämpat mot MCAS trots att det inte hade behövts.
I en av länkarna till lasternassumma är det en 737-pilot som riktar sig direkt till dig OY!
(www.pprune.org%2Frumours-news%2F619272-ethiopian-airliner-down-africa-102.html)
Second: For all the arm-chair Monday morning QB's who are saying: "Oh, they should have recognized it immediately and disconnected the trim:"
(1) Just after takeoff there is a lot going on with trim, power, configuration changes, and as noted above, the darn speed trim is always moving that trim wheel in seemingly random directions to the point that experienced NG pilots would treat its movement as background noise and normal ops. Movement of the trim wheel in awkward amounts and directions would not immediately trigger a memory item response of disconnecting the servos. No way.
(2) The pilots could very reasonably not have noticed the stab trim movement. Movement of the stab trim on the 737 is indicated by very loud clacking as the wheel rotates. On the -200 it was almost shockingly loud. On the NG, much less so. HOWEVER, the 737 cockpit is NOISY. It's one reason I am happy to not be flying it any more. The ergonomics are ridiculous. Especially at high speeds at low altitudes. With the wind noise, they may not have heard the trim wheel moving. The only other way to know it was moving would be yoke feel and to actually look at the trim setting on the center pedestal, which requires looking down and away from the windows and the instruments in a 'leans'-inducing head move. On the 717, for example, Ms. Douglas chimes in with an audible "Stablizer Motion" warning. There is no such indication on the 737.
(3) The fact that they were at high power and high speed tells me the stick shaker was activated. With that massive vibrator between your legs, alternating blue sky and brown out the window, your eye balls bouncing up and down in their sockets as the plane lurches up and down in positive and negative G's, it would have been a miracle if one of the pilots calmly reached down, flicked off the stab servo cutout switches, folded out the trim handle, and started grinding the wheel in the direction of normalcy. These pilots said over the radio that they had "unreliable airspeed". So they did not even know which instruments to rest their eyes on for reliable info. Their eyes were all over the cockpit looking for reliable info, the plane is all over the place like a wild boar in a blanket not behaving in any rational way. And the flying pilot may have been using the tiny standby IFDS for airspeed and attitude. Ouch.
Finally, runaway stab trim is a very, very rare occurence up until now. We trained it about once every other year in the sim because it is so rare. And when we did it was obvious. The nose was getting steadily heavier or steadily lighter with continuous movement of the trim wheel. That is a VERY different scenario than what these pilots faced.
We also trained for jammed stabilizer, the remedy for which is overcoming it with force. The information they were faced with could very reasonably have been interpreted that way, too.
r går i tredje världen där de dels är gamla, dels opereras av företag som inte är i närheten av vårt säkerhetstänk. Dessutom gäller väl det även den tekniska biten också...