A newly revealed software issue on some Boeing 737 MAX aircraft will delay regulatory certification for Boeing’s MAX 10, the head of the Federal Aviation Administration said Monday.

The software issue, which switches off some automated flight guidance when pilots alter their preprogrammed flight path, doesn’t mean MAX aircraft are unsafe, FAA administrator Bryan Bedford said Monday. He compared the software issue to a bug on the latest iPhone or a glitch in a Microsoft software update. 

But the FAA is studying the “workload component,” Bedford said, to determine how the software issue affects the flight crew and if that could pose a safety concern in certain circumstances.

That determination will hold up the FAA’s certification of Boeing’s long-delayed MAX 10, Bedford said Monday, confirming what many suspected when news of the software issue first broke this weekend. 

“We haven’t concluded whether this is a safety of flight issue or not, but we will be delaying the 10 until we’re satisfied that we don’t have an issue here,” Bedford said, speaking to reporters at an unrelated event about a project to modernize the nation’s air traffic control system. 

The issue marks another setback for Boeing’s MAX 10, its largest MAX variant and the second of two new MAX models that have been delayed for years as Boeing addressed manufacturing concerns and regulatory scrutiny following two fatal 737 MAX crashes in 2018 and 2019. 

The FAA certified the MAX 7, the smallest MAX variant, last month and Boeing expected MAX 10 certification would follow soon after. CEO Kelly Ortberg said at a financial conference this month that Boeing had completed all flight testing for the MAX 10, adding the 10 is “coming very shortly.”

The new issue affects some MAX aircraft operating with a certain software version, including the MAX 7 and 10. Not all airlines flying the already certified 737 MAX 8 and 9 use that version of the software, so many aircraft in the skies today are not impacted by the issue. 

Though already certified by the FAA, MAX 7 deliveries and entry into service could also be disrupted by the software issue. 

The MAX 7 and 10 account for about 37% of Boeing’s total MAX backlog, with 254 and 1,535 orders, respectively, analysts from RBC Capital wrote in a note to investors Monday. 

Boeing hadn’t calculated any deliveries of the MAX 7 or 10 in its 2026 guidance but a delay in production or deliveries could impact its future financials, the analysts continued. 

More broadly, “the ongoing investigation does not reflect positively on the near-term goal of restoring confidence with the FAA following critical flaws with the 737 MAX,” the analysts wrote.

Boeing’s stock was down nearly 7% Monday after news of the software issue and the certification delay.

Boeing notified operators of the software issue last month and is working with the FAA to develop a software update to address the concern, the company said on Saturday. 

The glitch causes the aircraft to switch from vertical navigation mode to a simpler level of automation when pilots veer from their preprogrammed flight path, Boeing said, meaning pilots need to perform extra steps for landing on the next approach. The Wall Street Journal first reported on the software issue.   

On Monday, a Boeing spokesperson said the company continues “to follow the lead of the FAA” as it works through the process to certify the MAX 10. 

A spokesperson for GE Aerospace, which makes the software, said the company is working closely with Boeing and supports the FAA’s evaluation.

An FAA spokesperson said that “safety dictates the certification timeline. We’re following our safety review process to investigate this software glitch and won’t hesitate to take action if needed.” 

At the news conference Monday, Bedford told reporters that this software issue is not related to a previous issue that caused the two fatal MAX crashes in 2018 and 2019. In those cases, a faulty software system on the then-new MAX, known as the Maneuvering Characteristics Augmentation System, or MCAS, repeatedly forced the plane’s nose down in both instances, leaving pilots unable to control the aircraft. 

Unlike MCAS, Bedford emphasized, this software issue “doesn’t take control away from the pilots.”