The eleventh Lockheed Martin F-35 flight-test aircraft is expected to begin taxi trials during the week of 10 January ahead of first flight as the $380 billion programme faces the consequences of the most sweeping government review to date.
The maiden sortie of the BF-5, the last of five short take-off and vertical landing jets in the flight-test fleet, follows the 30 December first flight by the AF-4 conventional take-off and landing variant (below).
Along with BF-5, two other F-35 flight-test aircraft - carrier variants CF-2 and CF-3 - failed to enter flight tests in 2010 as scheduled. The programme's overall flight test schedule remained on track, however. Nine aircraft completed 410 flight tests, completing 3,793 test points - both exceeding expectations.
But the programme enters the year facing uncertainty. So far, Lockheed officials have declined to specify a number of test flights scheduled for 2011, although programme officials previously estimated about 1,000 sorties would be necessary to keep the programme on track.
Lockheed plans to introduce a new metric for measuring flight-test progress, saying only the new goals will not be as simple as the 2010 objectives, which specified 394 test flights and 3,772 test points.
More broadly, the F-35 programme's development and production plans have been in flux for nearly eight months.
Last February, Vice Adm David Venlet assumed control of the joint programme office after his predecessor was sacked. Venlet initiated the last and most comprehensive in a two-year series of reviews of the programme's status, attempting to establish an achievable new baseline.
Venlet is expected to deliver the results of that technical baseline review later this month. Top US Department of Defense officials received a preview of the findings in late November. Since then, industry observers have speculated about a wide range of possible changes, with a focus on a likely new round of production cuts and development delays.