PPRuNe Forums - View Single Post - Ethiopian airliner down in Africa
View Single Post
Old 15th Mar 2019, 21:29
  #1543 (permalink)  
Sailvi767
 
Join Date: Dec 2013
Location: US
Age: 66
Posts: 598
Likes: 0
Received 8 Likes on 4 Posts
Originally Posted by joig
How many turns does it take to go from max down to say a neutral position? Given they they were never that high from the ground , How long would it take them to trim from max down to something that would save the flight? What am trying to say is OK we have a trim problem disable trim motor via cut out switches.. Turn the manual trim wheel . Would they have the time to do this if the are only approximately 1000ft above ground?
Depending on speed they aircraft can be controlled with full nose down trim. It’s highly unlikely MCAS trimmed the aircraft full nose down since it only moves in increments of 2.5 degrees and if the pilot countered it with the electric trim the aircraft would remain close to a trimmed state. Any pilot with a basic level of competence would counter the trim to attempt to remain in trim. The MCAS if getting bad inputs would again after a period of time input 2.5 units of trim again. It’s not instantaneous and the pilot would be alerted by feel, sight and noise. At the point you would expect the pilot to disconnect the trim and continue the flight using manual trim. Pretty much a non event for a competent crew.
Sailvi767 is offline