The F-35 Joint Program Office and Lockheed Martin have finalised the contract for the production and delivery of up to 398 F-35s, costing a total of £25bn, for the US, international partners and Foreign Military Sales aircraft in Lots 15 and 16.

There is also the option to include Lot 17.

The Pentagon and Lockheed Martin have announced the finalisation of a contract for the production and delivery of up to 398 F-35 aircraft, at a cost of $30bn.

The deal includes 145 aircraft in Lot 15, 127 in Lot 16, and the option to include up to 126 in Lot 17, which would include the first F-35 aircraft for Belgium, Finland, and Poland.

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These aircraft will be the first to include Technical Refresh-3 (TR-3) hardware, which will enable Block 4 capabilities. TR-3 includes a new integrated core processor, a panoramic cockpit display, and an enhanced memory unit.

“Continuing to add new countries to our global F-35 fleet further validates the capability and affordability of this aircraft in providing 21st Century Security to nations and allies,” said Bridget Lauderdale, Lockheed Martin vice president and general manager, F-35 Program.

“There is simply no other aircraft that can do all that the F-35 does to defeat and deter even the most advanced threats.”

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Last year, the F-35 team was on track to meet its commitment of 148 aircraft deliveries, but a temporary pause in flight operations, which is still in effect, has prevented the necessary acceptance flight tests from being carried out.

Despite this, the F-35 has continued to demonstrate its capabilities worldwide and has seen international growth, with Finland, Germany, and Switzerland all signing Letters of Offer and Acceptance as a step towards procuring F-35 aircraft.

To date, 17 countries have participated in the F-35 program, and more than 1,870 pilots and 13,500 maintainers have been trained. The F-35 fleet has also surpassed over 602,000 cumulative flight hours.