F-35 Sustainment: Enhanced Attention to and Oversight of F-35 Affordability Are Needed

F-35 mission capable rates--a measure of the readiness of an aircraft fleet--have recently improved, but still fall short of warfighter requirements, as discussed in our draft report. Specifically, from fiscal year 2019 to fiscal year 2020, the U.S. F-35 fleets average annual (1) mission capable rate--the percentage of time during which the aircraft can fly and perform one of its tasked missions--improved from 59 to 69 percent; and (2) full mission capable rate--the percentage of time during which the aircraft can perform all of its tasked missions--improved from 32 to 39 percent. Both metrics fall below the services' objectives. For example, in fiscal year 2020 the Air Force F-35A full mission capable rate was 54 percent, versus a 72 percent objective. Since 2012, F-35 estimated sustainment costs over its 66-year life cycle have increased steadily, from $1.11 trillion to $1.27 trillion, despite efforts to reduce costs. The services face a substantial and growing gap between estimated sustainment costs and affordability constraints--i.e., costs per tail (aircraft) per year that the services project they can afford--totaling about $6 billion in 2036 alone (see fig.). The services will collectively be confronted with tens of billions of dollars in sustainment costs that they project as unaffordable during the program.