Single. Point. Of. Failure. An Update On The Crash Of The Ethiopian Boeing 737 MAX 8


March 20, 2019 by epoetus



  • Since the last post about this on Islander’s Voice, all of the 737 MAX 8 and 9 planes have been grounded – following the grounding of these aircraft by many countries
  • Just before the official White House announcement of the grounding, Boeing’s CEO called the President to urge him directly against grounding these planes
  • A key sensor for angle of attack became a single point of failure in the flight control system
  • Flight control system had total control and operated in the background
  • When the flight control system was reset by the pilots the Maneuvering Characteristics Augmentation System (MCAS) would restart and apply the lift adjustment again – increasing the flight adjustment
  • The actual maximum amount of adjustment applied was four times greater than what had been specified during the official review process – this refinement of the adjustment occurred during flight tests and was not communicated back to the FAA who used the lesser adjustment when initiating the investigation into the Lion Air crash in Indonesia
  • Pilots did not receive training on how to work with MCAS, despite the fact that the behavior of the system does not meet any known, expected behaviors that they receive during training
  • A release of a revision to this flight control system was delayed due to the 34 day partial government shutdown
  • Boeing engineers oversaw much of the review and analysis process for certification to expedite the approval in time with the approval of rival manufacturer Airbus’s aircraft release.
  • Given the economic value of such a product release to Boeing and the United States, the article (link below) does not dig into oversight from the greater executive office, the Senate or Congress, but an investigation has begun into understanding how this crash occurred and how the FAA could have prioritized the planes certification date over safety concerns

The Seattle Times Investigative piece on the Safety Issues Missed by the FAA and written by Dominic Gates

2 thoughts on “Single. Point. Of. Failure. An Update On The Crash Of The Ethiopian Boeing 737 MAX 8

  1. Barbara Wollman says:

    NPR (now NPB) interviewer (David?) Green tried to get an FAA representative to admit that they had disregarded caution when they initially refused to ground the MAX planes. The FAA representative kept saying that they were a “fact-based” organization and waited for all the facts before they would decide whether or not to ground the planes. Mr Green, politely but insistently, kept pushing for the FAA representative to respond to his question about human life being at risk. You — or some of your readers — may be interested in seeing if a transcript or archive is available.


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