Old 11th Feb 2019, 18:27
  #16 (permalink)  
Join Date: Feb 2009
Location: Seattle
Posts: 379
jimtx - you are right about MCAS addressing a hand flying, handling qualities issue. MCAS is active only when the autopilot is disengaged. You are also correct that a pilot paying close attention to pitch response will manage the stick (or in this case the column on 737) so as to command the pitch attitude needed to achieve the desired normal load factor / flight path angle. The issue here is that certification rules require that increasing pull pitch controller input must be needed to command ever increasing AOA / normal load factor. Without MCAS there are 737MAX flight conditions where AOA / normal load factor can increase with constant column pull such that the pilot would need to relax the pull force in order to avoid exceeding their target nose up pitch maneuver. This characteristic does not comply with certification requirements and thus MCAS was introduced to assure that a steady increase in AOA / normal load factor requires a steady increase in column pull force.
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