The latest report on the F-35 by the Director, Operational Test and Evaluation [1] (typically referenced as DOT&E) describes an aircraft that struggles to meet its operational goals, with under 50% of the fleet fully mission capable at any given time. In short, the F-35, while a very capable military aircraft when fully operational, is also a "hangar queen".
"The F-35 fleet can only perform the full range of its combat roles 30% of the time. This unreliability renders the entire program ineffective."
"The services consider an aircraft as mission capable if it can perform at least one of the program’s assigned missions. Such a threshold may be appropriate for a program like the C-17 transport, which has essentially a single mission. For a multi-role program like the F-35, however, a different standard should be used. Because the F-35 is designed to perform many missions, from delivering nuclear weapons to supporting troops on the ground, program officials aren’t even using the right yardstick to measure the aircraft’s performance.
Fortunately, such a yardstick does exist. It is the full mission capable rate, or the percentage of aircraft available to perform all the assigned missions. The testing director said the full mission capable rate standard is “a better evaluation of combat readiness” for the F-35 program. When this higher standard is applied to the F-35 fleet, the magnitude of the program’s failure becomes clear: DOT&E reports the full mission capable rate for the F-35 fleet was 30% in 2023."
Essentially, if a plane they approach cannot perform the role, they don't mark it as bad and move on until they find a plane capable, as long as the F-35 can perform a role.
Not very helpful if you need all planes for combat, or troop support immediately. Not very helpful if, unlike the US, you only have 70 planes spread across 5 bases.
1. https://www.dote.osd.mil/Portals/97/pub/reports/FY2024/dod/2...