DOT Audit Finds Gaps in FAA Oversight of United Airlines Maintenance

A recent audit by the Department of Transportation's (DOT) Office of Inspector General (OIG) has identified significant deficiencies in the Federal Aviation Administration's (FAA) oversight of United Airlines' maintenance procedures. The findings, detailed in report AV2026014, point to systemic issues, including a critical shortage of inspectors, missed mandatory checks, and the improper use of virtual inspections, raising questions about the effectiveness of the agency's safety supervision.

The core of the issue lies within the FAA's Certificate Management Office (CMO) responsible for United, which according to the DOT OIG report, suffers from a 33% vacancy rate for inspectors. This staffing shortfall has direct operational consequences, hindering the agency’s ability to conduct thorough surveillance and ensure the airline adheres to federal safety regulations.

Audit Findings and Deficiencies

The inspector shortage has led to a quantifiable decline in oversight. The OIG found that the CMO failed to complete 8 of 22 (36%) required inspections at United's essential maintenance providers in fiscal year 2023. This problem worsened significantly in fiscal year 2024, with the number of missed inspections climbing to 13 of 22 (59%). These providers, both domestic and international, perform critical work on United's fleet.

Furthermore, the audit highlighted resource constraints affecting specific aircraft programs. For United's fleet of 521 Boeing 737 aircraft, oversight is handled by only four partial program managers. The report also found that due to these constraints, approximately 40% of inspections intended to be conducted on-site were performed virtually in 2024. This practice contradicts FAA policy, which mandates postponing reviews that cannot be done in person.

Another major gap identified was the FAA's inability to effectively monitor United's Safety Management System (SMS). Inspectors reported a lack of training and direct access to the airline's SMS data, which is crucial for identifying and analyzing the root causes of maintenance issues. The OIG noted that five of its previous recommendations regarding FAA oversight of airline SMS programs, dating back to 2019, remain unresolved.

In response to the findings, the FAA stated it "will implement a more systemic approach to strengthen inspector capacity and will take other measures to ensure that staffing levels remain sufficient to meet surveillance requirements." United Airlines commented that it "has long advocated in favor of providing the FAA with the resources it needs for its important work."

Systemic Oversight Challenges

The issues identified at the United CMO are not isolated. The audit is part of a continuing series by the DOT OIG examining the FAA's oversight of major U.S. carriers. In February 2020, a similar audit found the FAA had not effectively overseen Southwest Airlines' systems for managing safety risks. An October 2021 report on American Airlines concluded the FAA lacked effective controls to ensure the carrier mitigated maintenance risks. Most recently, a July 2025 audit of SkyWest Airlines found the agency had not resolved persistent issues with that carrier's maintenance practices. This pattern suggests a broader, systemic challenge within the FAA's oversight structure, exacerbated by nationwide aviation workforce shortages.

What Comes Next

The OIG issued six new recommendations to the FAA aimed at addressing the identified shortcomings. The FAA has concurred with most of the recommendations and, according to the report, is expected to complete its implementation of corrective actions by the end of 2026. These actions will likely include a revised staffing model for the United CMO, updated guidance on the use of virtual inspections, and improved training for accessing and analyzing airline SMS data.

Why This Matters

This audit shifts the focus of aviation safety from airline performance to the regulator's capacity for effective enforcement. The findings highlight how administrative and staffing issues within the FAA can create potential safety vulnerabilities across the national aviation system. For the industry, it underscores the fragility of the oversight framework when faced with workforce shortages and the challenge of adapting traditional inspection methods to modern, data-driven safety systems.