ATW Editor's Blog

Fast answers needed on second MAX crash

by Karen Walker
Mar 10, 2019

It is not the air transport industry’s habit to rush accident investigations, for good reason. But in the case of Sunday’s crash of an Ethiopian Boeing 737 MAX 8, there is pressure to get at least some answers as soon as possible.

All 157 crew and passengers on the Ethiopian aircraft, operating ET302, were killed after it crashed minutes after takeoff on what should have been a routine flight from Addis Ababa to Nairobi. According to Ethiopian’s CEO, the pilot—an experienced captain with more than 8,000 hours—issued a distress call and requested clearance to return to the airport.

The other golden rule of airliner accident investigation is never to prejudge the cause. That is why investigations can be lengthy—they are meticulous collections of all evidence and examinations of what happened. More times than not in modern-day crashes, there is no single cause. A complex interrelation of factors plays its part; the absence of any part might have led to a different outcome.

But when, as is the case now, a brand-new airliner type is involved in two fatal crashes within six months, there is an understandable urgency to know what went wrong.

The investigation into the first MAX crash, operated by Indonesian LCC Lion Air, is not complete. But it focused on a system that Boeing introduced into the MAX software, the so-called maneuvering characteristics augmentation system (MCAS) designed to prevent the heavier MAX from stalling.  The Lion Air pilots seem to have fought that system when it was triggered by a faulty sensor, raising questions about how many MAX pilots knew about the MCAS and training procedures.

The worldwide publicity on the Lion Air crash means the MCAS’ role and operation should be well understood by all operators. Boeing briefed all MAX operators after that accident. But the first question on everyone’s mind is whether there is a common root to what happened in Indonesia and then in Ethiopia?

Accident investigators, FAA and Boeing will need to address that question as soon as possible. Their airline customers—especially those with the MAX in service—need that answer because the general media is already posing the question, “is the MAX safe?” Some US newspapers advised readers today how to check which specific aircraft type they might be scheduled to fly on via the airline websites.

Here are the known similarities within the first few hours of the Ethiopian crash: Same aircraft and engine type; similarly-experienced captains; good weather and visibility conditions; the crash happened soon after takeoff; whatever happened developed rapidly and catastrophically.

That is nowhere sufficient to conclude the cause of each crash was the same (and remember, the Indonesian crash is still under investigation). But it’s enough to mean the next 48 hours will be critical. Any indication to the experts that there is a link would likely mean, at the least, the issuance of an emergency advisory to MAX operators and FAA could potentially ground the aircraft, as it did the 787 after fire incidents related to its lithium-battery system occurred early in that aircraft’s in-service life.

For the same reason, any indication that there is no link between these two crashes is equally important. The Ethiopian aircraft cockpit voice and flight data recorders have been recovered quickly. Information on those recorders won’t determine what happened, but it may be able to indicate what can be ruled out. That will be important given that China, Indonesia, India and several airlines that operate the MAX decided to ground the aircraft until more is known from the Ethiopian crash.

US airline operators are still flying the MAX and expressing confidence in the plane. But the leader of the US Association of Flight Attendants has issued a public call for FAA to launch an investigation into the MAX. She points out that crews and passengers are expressing concerns. US airlines are going to hear more concerns unless and until something can separate the two crashes. The ET302 investigation is unusually significant.

Karen Walker

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