The F-35B is Britain's most expensive and advanced warplane.
Britan currently owns 17 F-35Bs and is expected to purchase 138 in total - but what is the difference between the A, B and C models?
The F-35 jet has three variants: the F-35A conventional takeoff and landing (CTOL) variant, the F-35B short takeoff/vertical landing (STOVL) variant, and the F-35C carrier variant (CV).
The three variants perform similarly and are mainly distinguished by their different basing requirements. As a result, the F-35B and F-35C have unique ways to take off and land - due to their requirements for short take-off and landing or landing on carriers.
Using much of the same parts across the three variants allows for service-specific aircraft while allowing for savings to be made as a result of parts and processes being common to all three variants.
The F-35A is the conventional takeoff and landing (CTOL) variant which is designed to operate from regular runways.
It is the only version to carry an internal cannon.
The F-35A is set to be the common F-35 as the US Air Force and the majority of their our allied air forces and Foreign Military Sales (FMS) nations will operate the F-35A.
Look out for the F-35A in the skies above Suffolk as they are set to receive their first F-35As by 2021, before eventually maintaining two operational squadrons there.
They are not capable of operating from the UK's Queen Elizabeth-class aircraft carriers.
The F-35B model short takeoff/vertical landing (STOVL) variant will be used by the Royal Navy and RAF.
It was designed to operate from austere, short-field bases and a range of air-capable ships - including the Queen Elizabeth class aircraft carriers.
The F-35B can also take off and land conventionally from longer runways at major bases.
Each 'B' variant of the jet costs around $122.4m - but Lockheed Martin say they expect this cost will be reduced in the future, starting with the F-35A and then moving on to the B and C.
The company said they will drive the 'A' model's price down to $80m.
In November, it was announced that Britain would more than double its number of F-35B aircraft after ordering a further 17 of the jets.
Britain eventually plans to have 138 F-35Bs.
The F-35C carrier variant (CV) is the carrier variant, designed to be the US Navy’s first stealth fighter and the world’s only fifth Generation, long-range stealth strike fighter designed and built explicitly for aircraft carrier operations.
The F-35C variant has larger wings and more robust landing gear than the other variants, making it suitable for the US Navy's catapult launches and fly-in arrestments aboard naval aircraft carriers.
Its wingtips also fold to allow for more room on the carrier’s deck while deployed.
The F-35C has a greater internal fuel capacity than the other two F-35 variants.