Old 29th Dec 2018, 15:13
  #45 (permalink)  
gums
 
Join Date: Jun 2009
Location: florida
Age: 76
Posts: 1,058
Salute!

One thing I would have hated in that left seat would have been the stoopid shaker remaining activated no matter what we did.

The trace we see from the previous flight clearly shows the shaker active until some "event" upon landing ( no flow chart, so I guess it was WoW), and it was clearly not operating as part of the MCAS implementation. The shaker remained active regardless of flap position, time after takroff and turning off the electrical pitch trim system ( those guys flew using the manual trim wheel, and I guess the captain let the FO do most stuff and just "tolerated" the shaker when he used his control). So now we see that the shaker is driven independently of MCAS. This had to be confusing, even if you knew all about MCAS. Especially if you had turned of the stab trim to get rid of the annoying nose down trim that Hal was commanding over and over and over and "went manual" ( feel the Force, Luke)

The maintenance log shows the wrenchbenders trying to cure the airspeed gripes, and one of the computer codes pointed to the AoA. Had they left that sucker alone we would not be here on this forum, huh? And why didn't the crew gripe about the incessant shaker?

Something bad happened from the AoA sensor along the path to the MCAS and the shaker. A good flow chart/block diagram would really help here, but I am not sure the current generation believes in those things anymore. ANother process was our "murder boards" where we crackerjack pilot/engineers briefed our system or proposal using said charts/diagrams, and then explaining each and every interface and results from failures all along the various paths Hal or the lowly carbon-based lifeforms could take.

Gums sends...
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