Boeing Flags 737 Max Software Glitch as FAA Reviews Fix

Boeing disclosed last month a software glitch on some 737 Max aircraft that could disrupt certain automated landing procedures, surfacing just as the manufacturer pushes for federal certification of the fourth and final model in its best-selling jet family.

The Federal Aviation Administration said Saturday that it is assessing the problem and "will take immediate action if it identifies a safety concern." The agency will also review Boeing's proposed fix.

The defect emerges after a missed approach, when pilots alter a preprogrammed flight path. In those cases, pilots must take additional steps to use automated tools on subsequent approaches, Boeing said.

"We shared information with operators that reinforced existing pilot procedures for safely handling such cases. Our engineers are working on a software update to permanently address the issue," Boeing said in a statement. The Wall Street Journal reported the issue earlier.

Boeing stressed that pilots are trained to land without the automated system. "We are working directly with airlines to formalize a procedure that will allow pilots to reenable automated vertical navigation should this situation occur," the company said.

U.S. carriers told CNBC they have no Max 8 or Max 9 jets with the updated software tied to the glitch in their fleets. Airlines can revert some Maxes to the older software version.

Southwest Airlines, an all-Boeing 737 Max operator, said it is "aware of the issue and is engaged with Boeing and the FAA." The carrier added that "none of our fleet is equipped with Version U.14, including new deliveries of Max 8 airplanes." United Airlines said it is also not accepting any Max deliveries fitted with the new software.

The exposure appears concentrated on the two models still in certification limbo: the Max 7 and the Max 10.

The FAA certified the Max 7, the smallest variant in the family, in early August with the newest software installed. It remains unclear whether the aircraft can be delivered or flown with an older software version.

Boeing CEO Kelly Ortberg told investors earlier this month that he expected FAA certification of the Max 10 "very soon." The glitch now clouds that timeline, though Boeing has not revised its forecast.

"We have been engaged with Boeing and the FAA and will continue to work closely with both as they evaluate this matter and determine next steps," Alaska Airlines, a Max 10 customer, said Saturday.

The defect lands after years of delays and safety crises for the Max program. Two deadly crashes of Max 8 aircraft in 2018 and 2019 killed 346 people. Investigators implicated a flawed flight control software system, since updated, in both accidents.

The stakes are large. There are 2,430 Max aircraft currently in service globally, according to Cirium.

For Boeing, the timing could hardly be more delicate. The company is counting on closing out Max 7 and Max 10 certification to complete the family and unlock deliveries to customers like Alaska and Southwest. How quickly the FAA accepts Boeing's software update will shape whether the Max 10 approval Ortberg promised arrives on schedule.