UK may not upgrade all F-35Bs to Block 4 standard

The United Kingdom may not upgrade all of its early model Lockheed Martin F-35B Lightning combat aircraft to the latest Block 4 standard later this decade, declaring it will decide numbers based on ‘military capability requirements’.

The UK government has said it has not yet decided how many of the 48 F-35Bs it will have received by 2026 will be upgraded to the latest Block 4 standard, noting any decision on numbers will be based on ‘military capability requirements’. (Lockheed Martin)

Answering a question in the House of Commons Minister of State at the Ministry of Defence (MoD), Jeremy Quin, said that, while the international Block 4 (full combat) upgrade has been costed into the UK’s procurement programme, the precise numbers of already-delivered jets to go through the retrofit process have not yet been decided.

“The F-35 Block 4 upgrade has been included in the UK F-35 programme budget since its inception. Decisions on the number of aircraft to be upgraded will be made on the basis of military capability requirements. The costs of the Block 4 upgrade are managed through the F-35 Joint Programme Office and, as one partner in the multinational F-35 programme, the UK is not in a position to share detailed cost information,” the minister said.