Boeing has found a software flaw in the 737 MAX that can knock out certain autopilot functions after a pilot aborts a landing and changes course, forcing crews to fly manually at low altitude, according to the Wall Street Journal.
The problem traces to an update in cockpit software. When pilots change their planned flight path after a missed approach, some autopilot functions can become unavailable — precisely the moment when a plane may be dealing with bad weather or other difficult conditions.
Boeing told airlines about the issue in late August and said it did not view it as a safety risk. “We shared information with operators that reinforced existing pilot procedures for safely handling such cases,” the company said in a statement to the Journal. “Our engineers are working on a software update to permanently address the issue.”
The Federal Aviation Administration is investigating and, according to a senior agency official cited by the Journal, could take action if it concludes the glitch is a genuine safety hazard.
Some of Boeing’s largest customers aren’t waiting to find out. Southwest Airlines and United Airlines have told Boeing they don’t want new MAX jets delivered with the affected software and have asked for the older version instead. Alaska Airlines, American Airlines, Southwest and United all say none of their current MAX jets are flying with the flawed software. Boeing says airlines can revert to the earlier software version.
Boeing does not know exactly how many MAX aircraft worldwide are currently running the affected update, because airlines aren’t required to tell the manufacturer when they install a software upgrade. There are 2,422 MAX 8 and MAX 9 jets in service globally, according to aviation-data firm Cirium.
This is the latest problem for a jet that has already been at the center of two deadly crashes and a mid-air door blowout.
A troubled program
Lion Air Flight 610 crashed in October 2018 and Ethiopian Airlines Flight 302 went down in March 2019, killing 346 people combined. Both crashes were tied to MCAS, a Boeing flight-control system that could push the plane’s nose down automatically after receiving bad angle-of-attack data. Regulators grounded the MAX worldwide, and the FAA didn’t clear it to fly again in the U.S. until November 2020, after Boeing made software, training and cockpit-procedure changes.
Boeing shares have fallen roughly 39% since the first crash on Oct. 29, 2018, from $324.59 that day to about $198 as of Friday.
The MAX came under fresh scrutiny in January 2024 when a door plug blew off an Alaska Airlines 737-9 shortly after takeoff. Investigators found four bolts meant to hold the plug in place had never been installed after factory work. The National Transportation Safety Board pinned the failure on inadequate Boeing training, guidance and oversight, and on weak FAA surveillance. The FAA responded by grounding 171 MAX 9 jets, tightening inspections at Boeing and supplier Spirit AeroSystems, and blocking Boeing from expanding MAX production until quality controls improved.
