Boeing flags 737 Max software glitch affecting some automated approach functions

Boeing said it flagged a software glitch last month on some 737 Max aircraft that could affect certain landing procedures, as the manufacturer seeks federal approval for the fourth and final model in its best-selling aircraft family.

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

Boeing said the issue could arise after a missed approach when pilots alter a preprogrammed flight path, and that pilots must take additional steps to use automated tools on subsequent approaches.

"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. The Wall Street Journal reported the issue earlier.

The company said 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," Boeing said.

U.S. airlines told CNBC that they do not have Max 8 and Max 9 airplanes with the updated software tied to the glitch in their fleets. Airlines can revert some Maxes to the older software version.

All-Boeing 737 Max carrier Southwest Airlines said it is "aware of the issue and is engaged with Boeing and the FAA."

It added that "none of our fleet is equipped with Version U.14, including new deliveries of Max 8 airplanes." United Airlines also said it's not taking any Max aircraft deliveries with the new software.

However, questions remain about the two other models, the Max 7 and Max 10. The Federal Aviation Administration certified the Max 7, the smallest of the Max family, in early August with the newest software installed. It wasn't immediately clear if the aircraft could be delivered or fly with an older version of software.

Additionally, Boeing CEO Kelly Ortberg told investors earlier this month that he expected FAA certification of the Max 10 "very soon."

The issue comes after years of delays of Boeing's Max planes following safety and manufacturing crises, including the two deadly crashes of Max 8 aircraft in 2018 and 2019 that killed 346 people. A flawed flight control software system — which has since been updated — was implicated in both crashes.

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