NEW YORK CITY: A US audit ordered after a close call on an Alaska Airlines flight in January found multiple instances of noncompliance at Boeing and Spirit AeroSystems, officials said on Monday.

The Federal Aviation Administration (FAA), which undertook a six-week audit of the two manufacturers following the January 5 incident, "found multiple instances where the companies allegedly failed to comply with manufacturing quality control requirements," the US agency said.

"The FAA identified noncompliance issues in Boeing's manufacturing process control, parts handling and storage, and product control."

The FAA statement is the agency's latest critical commentary on Boeing following the January mishap, in which a 737 MAX operated by Alaska Airlines suffered a mid-flight blowout of a fuselage panel, leaving a gaping hole in the cabin and triggering an emergency landing.

The FAA said it provided a summary of the audit to Boeing and Spirit. An agency spokesman said the summary would not be released publicly because the findings are part of the agency's ongoing investigation.

Last week, Boeing executives met with FAA chief Mike Whitaker, who gave the company 90 days to address quality control problems.

Boeing on Monday referred to Chief Executive Dave Calhoun's remarks after that meeting.

"By virtue of our quality stand-downs, the FAA audit findings and the recent expert review panel report, we have a clear picture of what needs to be done. Transparency prevailed in all of these discussions," Calhoun said. "Our Boeing leadership team is totally committed to meeting this challenge."

A review of Boeing's safety culture released by an FAA advisory panel last week found that Boeing staff were confused and distrustful of changes to safety reporting systems implemented by the aerospace giant after fatal plane crashes in 2018 and 2019.