It is expected that the UK will build a front-line fleet of four F-35 squadrons with each squadron having 12 jets. A fifth unit, an operational conversion unit, will also operate 12 aircraft.

The structure of the Lightning force is now somewhat clear.

17(R) Squadron is currently based at Edwards Air Force Base in the US and fills role of F-35B Operational Evaluation Unit.

617 Squadron will be based at RAF Marham and will be the first operational British F-35 unit in 2019.

809 Naval Air Squadron will also be based at RAF Marham.

2 more unnamed frontline Squadrons are to be established.

1 Operation Conversion Squadron will also be formed.

This information comes from Air Cmdr. Harvey Smyth, the commander of the U.K.’s Lightning Force, as told to reporters at a conference in London.

In 2015, the UK government’s Strategic Defence and Security Review confirmed a planned order of 138 F-35s, with 23 of them to be available for carrier duties by 2023.

The UK will have an operational fleet of around 63 aircraft which is less than half of the total number of F-35’s that the UK has agreed to purchase

However, as reported by AviationWeek, Smyth pointed out that “the total number would cover attrition replacements and the so-called sustainment fleet, which is defined as additional aircraft required to sustain the fleet to its out-of-service date as well as to cover maintenance. Other UK combat aircraft also have large sustainment fleets.”

The programme is progressing at a steady rate with the Royal Air Force recently starting in-flight refuelling clearance trials of its Voyager tanker with the F-35.

The F-35B’s maiden deployment is set for late 2017 and it’s bound for the Western Pacific. The jet will deploy aboard an amphibious flattop and the US Marine Corps are planning a more powerful escort force to support it, according to Admiral Scott Swift, head of Pacific Fleet, as reported by the Marine Times.

The F-35B has already flown from American assault ships as part of a series of tests, which largely went well.

Additionally, F-35 unit costs have been going down with each successive lot of aircraft and will continue to do so.