Lockheed Martin has delivered the first production F-35 Lightning II to the US military to reach a long-delayed milestone, but there remains no firm timetable for inducting the new aircraft into operational service.
US Air Force officials formally accepted series-production model AF-7 at Lockheed's final assembly plant in Fort Worth, Texas, on 5 May. The aircraft was then flown to Edwards AFB, California, to complete an airframe-specific flight test programme.
The hand-over marks the delivery of the first production jet nearly 10 years after Lockheed won the contract to deliver 1,763 F-35As to the US Air Force, plus a total of 640 F-35Bs and F-35Cs for the Marine Corps and navy, respectively.
"Today we begin to fulfil the vision of our government and international customers," said Larry Lawson, Lockheed's F-35 programme manager.
© Lockheed Martin
Aircraft AF-7 has been flown to Edwards AFB, California
The milestone has been delayed several years from the original timetable set after contract award in 2001, with a costly redesign adopted in 2004 and two major schedule delays announced since last February.
Until earlier this year, the air force had planned to stand-up the first operational F-35 squadron by 2016. The latest schedule, however, delays the end of developmental testing to the end of 2016, forcing the in-service date for the F-35A into at least 2017 or 2018. But the precise date had not yet been determined by the air force as of late April.
Despite the programme's cost and schedule setbacks, the F-35's leadership team points to a new wave of progress in manufacturing and testing.
Although the last of 13 flight test aircraft remains in final assembly, eight production-model jets from the first two lots of low-rate initial production (LRIP) have rolled out of the assembly line.
But the earliest production aircraft proved more costly than the government estimated, with Lockheed's bills running as high as 15% over budget for the first three lots of LRIP.