PPRuNe Forums - View Single Post - MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
Old 6th Jun 2019, 02:04
  #192 (permalink)  
fdr
 
Join Date: Jun 2001
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Originally Posted by Icarus2001
Except that it is not.

It can be overridden by the trim switch on the control column.

It can be switched off by using the switches on the centre console.

How is that "not capable of being overridden"?

Icarus, fair point. it was then just a stick pusher system added without the awareness of the crew, and led to 2 crews planting planes into the turf. Without that information the crew are left in the dark in a single AOA failure in flight, that they have lost more than just an indicator or input to the ADC etc, they have lost something that affects the control of the aircraft, and is not annunciated or reported as such. MMEL permits despatch with heaters inop for the AOA in certain situations, without the crew being aware that an inadvertent icing encounter now may affect a system that they were not aware of being available. The MMEL also permits despatch with one of the two control yoke trim switches inop, there is always a manual trim and the cutout as you indicate. If the fault occurs on departure, there would be a pilot with a pickle switch.. If it happens during a comfort stop, then the pilot in the cockpit has to use what he can reach to sort it out and that comes to using the cutouts.

I stand corrected, but it remains a lousy architecture that does not appear to meet the advisory requirements of certification of a SAS system.
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