The Federal Aviation Administration audit of Boeing's 737 Max jet production line found a plethora of issues with the production process.

Why it matters: Boeing, one of the world's largest aerospace manufacturers, has been under intense scrutiny in recent months after one of its 737 MAX 9 jets experienced a mid-flight door plug blowout while at an altitude of nearly 16,000 feet.

• "This won't be back to business as usual for Boeing. They must commit to real and profound improvements," FAA administrator Michael Whitaker said in a statement Tuesday.

State of play: In the aftermath of the incident, the FAA vowed to increase oversight of Boeing's production and manufacturing processes, including via an audit of the 737-9 MAX production line.

• The FAA's audit uncovered "non-compliance issues in Boeing's manufacturing process control, parts handling and storage, and product control," the agency said in a statement Tuesday.
• While the audit is complete, the FAA said it could not release further details due to the ongoing investigation.
• Whitaker said at a press briefing Monday said the issues discovered by the audit went beyond "paperwork issues" to include things like tool management and the order work is done.

Details: The FAA conducted 89 product audits looking at aspects of Boeing's production process — Boeing failed 33 of them, the New York Times reported.

• The FAA also conducted 13 product audits focused on Boeing's fuselage supplier Spirit AeroSystems. Spirit failed seven of the audits, per the Times.

The big picture: All Boeing 737 MAX 9 aircraft were temporarily grounded in U.S. territory after an Alaska Airlines flight saw its a "plugged" emergency exit door fly off mid-flight in early January.

• A federal watchdog said last month that preliminary findings indicated that missing bolts likely contributed to the incident. Other inspections by airlines of Boeing's MAX 9 jets revealed quality control issues, including loose bolts.
• The FAA has ordered Boeing to create a plan to address its "systemic quality-control issues."

What's next: The National Transportation Safety Board said via email Tuesday it has scheduled an investigative public hearing on the Boeing 737-9 MAX door plug blowout for Aug. 6 and 7.

Editor's note: This article has been updated with details of the NTSB's announcement.