Translating The 737 MAX 8 Crisis

By Robert Mark on March 29th, 2019

I rather fancy myself as a translator of aviation speak, trying to be sure people who read about our industry really understand what I’m trying to explain, whether that’s in print or online.

The past few weeks have been a nightmare for most journalists trying to explain the intricacies of the 737 MAX 8 & 9’s Maneuvering Characteristic Augmentation System, or MCAS.

Because of the weight and the placement of the new CFM International LEAP-1B engines added to create the MAX, the nose of the aircraft could pitch up more than most pilots might expect when power was added, especially at low speeds, like those experienced during takeoff.

Today I just read that the Ethiopian airplane was less than 1,000 feet above the ground when the MCAS apparently fired and wrestled control of the aircraft away from the pilots with obviously disastrous results. That wouldn’t have given them much time to react.

Right now, there’s little to be gained by explaining what the Ethiopian pilots should have done or what they should have known in order to maintain control of the airplane. Boeing certainly didn’t help the situation initially by not telling pilots the MCAS even existed. After the Lion Air accident, Boeing did publish a bulletin explaining that an MCAS upset could look very much like a trim runaway. Whether or not the Ethiopian crew saw the bulletin is anyone’s guess. If they did read it, why they were not able to disable the trim is another question we’ll need to wait for the final accident report to explain.

Since the Ethiopian accident, I’ve been asked more than a few times to provide some context to this saga, a context that non-industry people would understand. I spent some time yesterday with Mary Harris of’s “What Next,” podcast for just that reason and I wanted to share it with you. I thought Mary asked some really insightful questions. Hopefully, I offered a few insightful answers as well.

To listen to’s What Next podcast for March 29, 2019, click here. @slate


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2 Responses to “Translating The 737 MAX 8 Crisis”

  1. posa Says:

    So if the MCAS fix from Boeing is that pilots can readily disable it, then the question is whether the plane can be flown safely without MCAS for extended flights.

    If they can, then why was MCAS installed in the first place? If MCAS is REQUIRED to fly an otherwise unstable aircraft, how does disabling it make the Boeing MAX any safer?

  2. Michael Squire Says:

    The reason why these jets crash is that the operation of the aircraft is getting further and further removed from the pilots so they cannot “feel” what is wrong. They need to have a “computer kill” switch that allows the whole plane to be flown manually at any time. AND we should have known what was wrong with the first aircraft before the second one crashed. “Autopilot” has a lot to answer for.

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