F-35 Aircraft Sustainment: DOD Faces Challenges in Sustaining a Growing Fleet, Statement of Diana Maurer, Director, Defense Capabilities and Management, Testimony Before the Subcommittees on Readiness and Tactical Air and Land Forces, Committee on Armed Services, House of Representatives [open pdf - 802KB]
From the GAO [Government Accountability Office] Highlights: "DOD's F-35 Lightning II fighter aircraft provides key aviation capabilities to support the U.S. National Defense Strategy. The F-35 is also DOD's most costly weapon system, with U.S. sustainment costs estimated at more than $1 trillion over its life cycle. As of October 2019, there were more than 435 U.S. and international F-35 aircraft in operation, with more than 3,300 aircraft expected to be fielded throughout the life of the program. While there is little doubt that the F-35 brings unique capabilities to the U.S. military, DOD faces significant challenges in sustaining a growing fleet. This statement discusses F-35 sustainment challenges. It also summarizes GAO's open recommendations related to these challenges."
Government Accountability Office: http://www.gao.gov/