The UK has declared an overall requirement for 138 F-35B aircraft, although only 48 were included in the initial tranche. The first aircraft were delivered to RAF Marham in June 2018.
One aircraft, ZM152, was lost on November 17, 2021, after falling into the Mediterranean Sea following an unsuccessful take-off from the aircraft carrier HMS Queen Elizabeth. The wreckage was recovered in early December 2021.
The aircraft are currently engaged in operational tasks, including patrol missions from RAF Akrotiri in support of partners in the Middle East. Officials said the UK continues to maintain its commitment to acquiring a total of 138 aircraft.
A small number of the future fleet is expected to consist of the F-35A variant, intended for training and personnel development. These aircraft are also expected to be adapted to carry B61 nuclear bombs.
No contract has yet been signed to initiate deliveries under a second procurement tranche. Reports in British media indicate that the current fleet faces operational limitations related to personnel shortages, lower-than-expected readiness levels, and delays in integrating weapons and additional equipment.
Further constraints include the ongoing expansion of ground infrastructure within the United Kingdom, which has not yet been completed. These factors continue to affect the full operational potential of the fleet.
