FAA chief says ‘we’ve sort of stopped trying’ to predict when Boeing Max 9 flights will resume

The chief of the Federal Aviation Administration (FAA) shed doubt on the near future of the Boeing 737 Max 9 aircraft, following discoveries of manufacturing errors during widespread inspections of the airframe.

FAA Adminstrator Michael Whitaker said Wednesday the agency will keep “boots on the ground” at Boeing’s manufacturing plant until it can ensure the airframes are being constructed safely.

The Boeing scrutiny comes after the door plug of a 737 Max 9 aircraft blew out midflight over Oregon early this month, causing rapid depressurization and an emergency landing. Nobody was injured in the incident, but it sparked widespread inspections of other 737 Max 9 airframes that have discovered loose bolts and other manufacturing defects.

All similar 737 Max 9 aircraft have been grounded nationwide during the inspection process. Whitaker said he can’t guess when the planes will be in the air again.

“It’s been difficult to predict, so we’ve sort of stopped trying,” he told CNBC. “But as soon as we get it sorted out, it’ll be up again.”

Whitaker said FAA audits of the aircraft are taking more than eight hours each, twice the initial prediction when the agency announced inspections. 

“We’ve required a lot of measurements,” he said. “Once the area’s exposed, we want to understand bolt tensions and gaps and things of that nature. So we’ve required more data than would normally be the case because we really wanted to understand the issue.”

The 737 Max 9 scrutiny has also impacted airlines. United Airlines CEO Scott Kirby said Tuesday he is “disappointed” over the problems, and the airline may look to other manufacturers for future aircraft purchases.

“We’re Boeing’s biggest customer in the world. They’re our biggest partner in the world,” Kirby said in a separate CNBC interview Tuesday. “We need Boeing to succeed … but they’ve been having these consistent manufacturing challenges and they need to take action together.”

He added he is confident the aircraft will be safe once inspections are complete.

“The FAA, to their credit, has been in there with us in the weeds, on weekend, late nights,” Kirby said. “So, I think we’re near the end game on that and the airplane will be safe, but I’m disappointed that the manufacturing challenges do keep happening at Boeing. This isn’t new.”

Boeing’s stock has fallen nearly 20 percent this month on the news.