Rolls-Royce has completed the first lift fan for the Lockheed Martin F-35B to be produced at a $13 million final assembly plant opened 17 months ago.
The London, UK-headquartered manufacturer was due to deliver the first module - the 12th lift fan to be completed overall - to Lockheed on 4 October.
The roughly 1,220kg (2,690lb) lift fan activates in short take-off and vertical landing modes for the F-35B, generating an output of 19,000lb-thrust (85kN).
The fan combines with a three-bearing swivel nozzle in the exhaust and twin roll posts.
The overall system creates 40,700lb-thrust, allowing the F-35B to hover and take-off from the US Marine Corps' LHD-class amphibious carriers.
Rolls-Royce expects the new facility in Indianapolis, Indiana, to build 84 lift fans each year - although expected commitments for the F-35B have fallen in the last year, from about 520 to 400 orders.
The US Department of Defense also has frozen orders for the F-35B at six per year through 2013.
The production freeze, in particular, has made it challenging for Rolls-Royce to meet cost targets for the lift fan component, said Gregg Pyers, the company's lift fan programme director.
But the manufacturer has so far minimised changes to its production system. Although the UK Royal Navy has dropped out of the programme, Rolls-Royce has no plans to transfer work on lift fan components from the UK to Indianapolis, Pyers added.