The UK has taken delivery of its first of three F-35B Joint Strike Fighter test aircraft at Lockheed Martin’s Fort Worth site in Texas, while defence secretary Philip Hammond has announced plans to order a fourth example next year.

Short take-off and vertical landing aircraft BK-1 will soon be transferred to Eglin AFB in Florida to join US-led initial operational test and evaluation (IOT&E) of the F-35.

 F-35 BK-1 flag - Lockheed Martin

Lockheed Martin

Hammond also revealed that the Ministry of Defence currently favours the Royal Air Force’s Marham base in Norfolk to become the main operating site for its F-35B Lightning IIs, "but that no decision has yet been made". Land-based trials of the type are due to commence in the UK in 2018, following the nation’s involvement in the IOT&E phase of the programme.

To be flown by RAF and Royal Navy pilots, the UK’s F-35Bs will also be operated from at least one of the latter service’s future two Queen Elizabeth-class aircraft carriers from around 2020.