Military Depots: The Navy Needs Improved Planning to Address Persistent Aircraft Maintenance Delays While Air Force Maintenance Has Generally Been Timely
Three Air Force and three Navy aviation depots maintain critical aircraft such as the KC-135 tanker and F/A-18 fighter. Delays at depots can reduce aircraft availability for operations and training.
We reviewed depot performance for selected aircraft over 6 years.
Air Force depots completed maintenance on-time or early in 5 of 6 years (with aircraft in maintenance 22,572 fewer days than expected)
Navy depots were late all 6 years (over 62,000 more days than expected)
We also identified Navy planning challenges, such as a need for more effective use of historical maintenance data. We made 3 recommendations to the Navy to reduce delays.
An F/A-18 undergoing depot maintenance at Fleet Readiness Center Southwest in San Diego.
Fighter plane in hangar
What GAO Found
The Air Force and Navy varied in the extent that they completed depot maintenance on time for selected fixed-wing aircraft in fiscal years 2014 through 2019. Specifically, GAO's analysis of aggregate maintenance data found that:
Air Force depots completed aircraft maintenance on time or early in 5 of 6 years, with percentages for on-time or early-completion maintenance ranging from 78 to 90 percent.
Navy depots completed aircraft maintenance late for each of the 6 years, with percentages for on-time or early-completion maintenance ranging from 45 to 63 percent. Navy fixed-wing aircraft have spent over 62,000 more days in maintenance than expected since fiscal year 2014.
Aircraft Maintenance Completed On Time or Early by Service, Fiscal Years 2014 through 2019
The Air Force generally has accurately planned for depot maintenance requirements for selected fixed-wing aircraft during fiscal year 2014 through 2019, but the Navy has not. Both services have initiatives underway to improve planning for aviation depot maintenance; however, GAO identified planning challenges that the Navy has not fully addressed:
The Navy has not effectively used historical data to analyze turnaround time—total days planned for depot maintenance periods—and established accurate planning targets for aircraft maintenance packages.
Navy depot planners do not have visibility into aircraft maintenance that is performed outside the depots by an operational unit or other maintenance facility—information critical to planning for the condition and depot maintenance needs of individual aircraft.
The Navy does not yet have formal processes and related guidance for communication and coordination between depot stakeholders to inform maintenance requirements planning.
Without addressing these challenges, the Navy cannot appropriately plan for depot maintenance workload and will likely continue to experience maintenance delays that reduce the time aircraft are available for operations and training.
Why GAO Did This Study
Three Air Force and three Navy aviation depots maintain critical fixed-wing aviation platforms, such as the KC-135 aerial refuelers and F/A-18 fighters. The ability of these depots to complete maintenance on time directly affects military readiness because delays reduce the time aircraft are available for operations and training.
Senate Report 115-262, accompanying a bill for the Fiscal Year 2019 National Defense Authorization Act, contained provisions that GAO examine the Department of Defense's (DOD) aviation depots. GAO's report evaluates the extent to which 1) the Air Force and Navy aviation depots completed selected fixed-wing aircraft maintenance on time from fiscal year 2014 through 2019, and 2) the Air Force and Navy accurately planned for depot maintenance requirements from fiscal year 2014 through 2019 and addressed any associated challenges.
GAO selected a non-generalizable sample of 18 Air Force and 18 Navy fixed-wing aircraft types; analyzed maintenance and planning data for fiscal year 2014 through 2019; and interviewed service officials.
GAO is making three recommendations to the Navy: to use historical data to set turnaround time targets for depot maintenance; provide planners information on maintenance performed outside the depots; and establish processes for communication between depot stakeholders. DOD concurred with all three recommendations.
Recommendations for Executive Action
|Department of the Navy||The Secretary of the Navy should ensure that Naval Air Systems Command and Commander, Fleet Readiness Centers effectively use historical data to analyze turnaround time and establish accurate turnaround time targets for fixed-wing aircraft depot maintenance packages. (Recommendation 1)||
The Navy concurred with our recommendation. In February 2022, the Navy provided documentation showing that the department has implemented the Naval Sustainment System for Aviation initiative across the F/A-18E-F, EA-18G, E-2D, MV-22, and CH-53E aircraft fleets. This initiative utilized both historical data and readiness goals to establish turnaround time targets to minimize Out of Reporting aircraft quantities. As a result, the Navy is now using realistic turnaround time targets for their fixed-wing aircraft depot maintenance packages.
|Department of the Navy||The Secretary of the Navy should ensure that Commander, Naval Air Forces and Commander, Naval Air Force, Pacific provide depot planners regular reporting on fixed-wing aircraft maintenance performed outside the Navy aviation depots by an operational unit or at an intermediate maintenance facility to ensure they have information on the current condition and depot maintenance needs of individual aircraft. (Recommendation 2)||
The Navy concurred with our recommendation. In February 2022, the Navy developed a requirements document for an IT system that was intended to unify and digitize data from the organizational, intermediate, and depot-levels. In January 2023, the Navy established requirements for an IT system in alignment with the Program Executive Office for Manpower, Logistics, and Business Solutions (PEO MLB) as an overall strategy for its IT portfolio, according to Navy documentation. Further, according to a Navy memo signed in January 2023, the PEO MLB is authorized to proceed with acquisition of an IT system for aviation organizational, intermediate, and depot-level tool suites, among others. Further, it states the Navy can begin planning in support of fiscal year 2025 execution of associated requirements pending final determination and approval through the Navy Program Objective Memorandum (POM) process. Given that the IT system is not operational, we are updating the status of our recommendation to partially implemented and will continue to monitor the Navy's progress in fully addressing our recommendation.
|Department of the Navy||The Secretary of the Navy should ensure that Naval Air Systems Command and Commander, Fleet Readiness Centers establish formal processes and related guidance for communication and coordination between depot stakeholders to inform maintenance requirements planning. (Recommendation 3)||
The Navy concurred with our recommendation. In January 2023, the Navy provided documentation showing that that formal Standard Work Packages and OPNAV-level instructions on the depot planning process have been reviewed, signed, and are in use. This guidance establishes processes for communication and coordination between depot stakeholders to inform maintenance requirements planning and outlines roles and responsibilities of various positions in the participation and coordination of a pre-induction review. These actions taken by the Navy will help ensure that all subject-matter expert input is proactively solicited and incorporated into depot workload planning.