737 Max Pilots Have 40 Seconds to Fix Problem

Flight simulations have found that Boeing 737 Max pilots would have less than a minute to disengage an automated system and manually prevent a nosedive caused by a failed sensor—the scenario that is suspected in two recent airliner crashes. The sensor failure causes software designed to prevent a stall to kick in, the New York Times reports. That's when the pilots in the tests found out they would have 40 seconds to override that system and prevent a nosedive. To do that, they'd have to flip three switches and turn a wheel. If they don't act quickly enough, attempts to override the system won't work. Lion Air pilots threw a thumb switch more than two dozen times, but the system kept engaging, causing the nosedive.

It's debatable whether pilots have had enough training on the 737 Max. Ethiopian Airlines says the pilots on its doomed plane were trained on "all appropriate simulators." But training on this system has been limited, and the Lion Air captain was futilely relying on a technical manual just before the crash to diagnose the problem. Boeing hopes to address the problem with a software update that would give pilots more control, people involved told the Times. The thumb switch can lengthen the 40-second period to several minutes, but even that might not be enough time if the crew isn't knowledgeable. That appears to be the case in the Lion Air crash. "There is a limited window to solve this problem," an aviation safety consultant says, "and this crew didn't even know that this system existed." (More Boeing 737 stories.)