A ceremony to mark the latest stage in the manufacturing of the world's most costly military aircraft project, the F-35, is taking place in Lancashire.
Britain plans to take delivery of 138 Joint Strike Fighters
BAE Systems is to hand over the jet aft fuselage to customers Lockheed Martin in a ceremony at the Salmesbury plant.
The aft fuselage for the first Short Take Off and Vertical Landing variant of the F-35 Lightning II represents a BAE Systems contract worth £1.3bn.
The £140bn Anglo-American project will supply jets to a number of countries.
The UK is expected to take delivery of 138 fighters and the US is planning to have 2,400 jets in service by 2027.
A jump-jet version of the F-35 will be deployed by the Royal Air Force and Royal Navy.
Along with the US and Britain, the F-35 is being co-financed by Australia, Canada, Denmark, Italy, the Netherlands, Norway and Turkey.