Previously on this topic: “Is It Time to Worry About the Boeing 737 Max?,” “A Shorter Guide to the Ethiopian Tragedy and the 737 Max,” “What Was On the Record About Problems With the 737 Max,” “‘Don’t Ground the Planes, Ground the Pilots,’” “The Implications of the 737 Max Crashes,” and “Training, Regulation, and the 737 Max.”
A few hours ago Bloomberg broke a story, by Alan Levin and Harry Suhartono, with a potentially significant detail about the first of the recent two crashes of the Boeing 737 Max. This was the crash last October of a Lion Air flight, into the sea off Indonesia, in which all 189 people aboard died. (The second, outside Addis Ababa, was of an Ethiopian Airlines flight this month, causing 157 deaths.)
The Bloomberg story says that just one day before the fatal Lion Air accident, the very same airplane had suffered a similar pitch-control anomaly. But in this preceding case, an additional pilot, riding in the jump seat of the cockpit, recognized the problem and overrode part of the errant control system. The plane flew on to its destination.
The Bloomberg story says:
That extra pilot, who was seated in the cockpit jumpseat, correctly diagnosed the problem and told the crew how to disable a malfunctioning flight-control system and save the plane, according to two people familiar with Indonesia’s investigation.
If true, this detail would shed light on what I suggested earlier was the crucial question about the fatal Lion Air flight: whether its pilots did not know how to override or offset a failing system, or whether they knew what to do but could not achieve it, because the command systems failed to respond or stop the descent.
Again if true, this report would suggest:
- That one specific aircraft—not the 737 Max model line as a whole, but the specific airplane that eventually crashed—had an instrument failure, presumably the “angle of attack” indicator that triggered the automatic pitch-control system. It would suggest that the instrument failed one day; the flight crew coped; the same airplane was sent up with the same failure-prone sensor the next day; and this time the results were tragically different.
- That flight crew training and familiarity played a fundamental role in the overall 737 Max drama. That is, a pilot who knew what was happening, could correct the situation; and pilots who didn’t, couldn’t, and flew to their (and their passengers’) deaths.
Does this detail, if confirmed, establish the cause of the second crash, on Ethiopian Airlines? Not necessarily. That investigation goes on.
Does it establish whether the 737 Max is “safe” or “dangerously flawed”? Again, not in itself.
But if true, it could be significant in emphasizing the importance of familiarity, and awareness of the MCAS pitch-control traits (and possible sensor errors or “failure modes”), in safe flight aboard the 737 Max. At face value it would indicate that the very same airplane, with the very same (or similar) defect, completed a flight one day, and plunged into the sea the next day, with the life-and-death difference turning on whether someone in the cockpit recognized what an automated system was trying to do.
Think of this, the next time you hear that modern airplanes “just fly themselves,” with professional pilots as paid bystanders.
And investigators will think of it, in assessing whether Boeing, the FAA, and airlines adequately alerted pilots to the traits of this new airplane. (Also see a relevant earlier post, “Don’t Ground the Airplanes. Ground the Pilots.”)