GAO report finds F-35 sustainment challenges hinder aircraft availability

The US Department of Defense describes the Lockheed Martin F-35 Lightning II as a “multirole fighter that combines stealth, sensor fusion and unprecedented situational awareness”. (US Air Force)

The Government Accountability Office said in a recent report that the Lockheed Martin F-35 Lightning II failed to meet performance goals across the fleet from fiscal year (FY) 2021 through FY 2025.

The June 2026 report stated that the mission capable rate, or the percentage of time the aircraft can perform one of its tasked missions, declined from 67 % to 44 % in that window while the full mission capable rate dropped from 38% to 25%.

The report concluded that “the F-35 has not met warfighter requirements for sustainment performance, reducing the number of F-35s available to the U.S. military services. Furthermore, sustainment performance has declined each year since 2020 due to longstanding challenges with both supply and maintenance”.

The GAO said reliance on private contractor parts and rise in F-35 costs mean that “US military services will annually face a more than $1 billion gap between the projected costs to sustain their F-35s and their affordability goals by the mid-2030s”, the report said.

The F-35A variant, in use by the US Air Force (USAF), had the highest mission capable rate in FY 2020 at 71.4%, but dropped to just 38.6% in FY 2025.

The F-35B, in use by the US Marine Corps (USMC), dropped from 67% mission capable to 53.9% in the same time frame.

The F-35C variant, which the USMC also employs, see-sawed between FY 2020 (57%) and FY 2025 (64.2%), reaching a high of 66.3% in FY2021 where its aircraft were mission capable.