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Old 18th Apr 2019, 23:35
  #4124 (permalink)  
Bend alot
Join Date: Oct 2017
Location: Tent
Posts: 262
Originally Posted by L39 Guy View Post

MCAS is a required stall protection however it needs to be toned down a bit as it can move the stabilizer trim to very large aircraft nose down angles.
34 years aircraft maintenance.

Good post L39 - but MCAS is far from a stall protection (system). MCAS is a system that supplies an a feel to the control column, and the aircraft can fly perfectly without it.

But without MCAS the 737 MAX could not meet the certification requirements for Grandfather rights. Without the Grandfather rights the 737 MAX requires more certification and pilots will require extra training - this would make the MAX less desirable/competitive.

So the task was to incorporate a new system without calling it "new" and retain Grandfather rights. It seems to me that the priority was the "extra training" being minimal between the MAX and other 737's (you heavily touched training in your reply) and the result was a few hours of slides on an iPad that included nothing on the new system.

If the Grandfathering certification allowed for MCAS as a new system, and it was designed and implemented as a stand alone system with dedicated on/off switches and proper training - I doubt we would have had the crashes.

Even now MCAS seems to be strange! (I do not recall exact numbers) but MCAS was said to have a limit of 0.6 in certification. From memory that was not enough so it was increased to 2.5 to get the required "feel" to pass the test. Yet the "software update" will reduce this to either 0.6 or 0.9 ( I do not recall) so how then can it pass the test when 2.5 was required?

There also still seems to be far too much effort, to not have this aircraft require "extra" training, particularly in the sim. My view is that this "fix" will have put the "feel" somewhat less than what the original MAX had, this feel was to give the pilot an aid to prevent pulling back too far preventing a stall. So I believe that simulator training should be carried out on the MAX around the stall area in the parameters that MCAS is enabled. Obviously this training should be with and without MCAS engaged as there is included in the fix more ways the MCAS can be disengaged, and pilots left with a soft stick around the stall zone.

Further more, given it seems decisions at Boeing have been made heavily for financial reasons on the MAX project - I would hope a full review of the certification is/has been made external of Boeing.

Training - FAA and Boeing seem against it other than an iPad slide show, a few more craters till that changes.

The faults in the US reported of altitude change when AP selected - has this problem been identified and rectified?
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