A Government Accountability Office (GAO) study examining Department of Defense (DoD) weapon system sustainment maintains aircraft mission capable goals were generally not met and sustainment costs varied by aircraft.
The GAO report provided observations regarding mission-capable rates and costs to operate and sustain 49 fixed- and rotary-wing aircraft in the Army, Navy, Marine Corps, and Air Force.
The agency also initiated the work in accordance with its response to a provision in section 802 of the William M. (Mac) Thornberry National Defense Authorization Act for Fiscal Year 2021 for GAO to report on sustainment reviews conducted by the military services.
The GAO found that four of the 49 examined aircraft met their annual mission capable goal in a majority of the years from fiscal years 2011 through 2021, while 26 aircraft did not meet their annual mission capable goal in any fiscal year.
According to the GAO, the mission capable rate is used to assess the health and readiness of an aircraft fleet and is defined as the percentage of total time when the aircraft can fly and perform at least one mission.
According to the GAO, operating and support (O&S) costs totaled $54 billion in fiscal year 2020 for the reviewed aircraft, representing a decrease of $2.9 billion since fiscal year 2011 after factoring in inflation using the constant fiscal year 2020 dollars.
Air Force and Army O&S costs have decreased while Navy and Marine Corps O&S costs have increased, the GAO noted. The trends have been driven by changes in the size of aircraft inventory and reduced flying hours.