Boeing, the aircraft manufacturing giant, faced a significant setback after a door panel blew off a 737 Max 9 during an Alaska Airlines flight in early January, prompting the Federal Aviation Administration (F.A.A.) to conduct a six-week audit of the company’s production process. The audit revealed numerous issues in the manufacturing process of the 737 Max jet, both at Boeing and its supplier, Spirit AeroSystems.

The F.A.A. deployed as many as 20 auditors at Boeing’s plant in Renton, Wash., where the 737 Max is built. The findings of the audit, although not publicly detailed by the agency, were reviewed in a slide presentation by The New York Times. The presentation disclosed that Boeing failed 33 out of 89 product audits, with a total of 97 instances of alleged noncompliance.

Similarly, Spirit AeroSystems, responsible for manufacturing the fuselage of the 737 Max, underwent 13 product audits, with six instances of noncompliance reported. The detailed technical assessment provided a comprehensive overview of the manufacturing lapses at both Boeing and its supplier.

Since the Alaska Airlines incident, Boeing has been under intense scrutiny regarding its quality-control practices. The findings of the F.A.A. audit have further intensified the spotlight on the company’s production processes, raising concerns about air safety and quality control standards.