F-35 flight test update: One step forward, two steps back?

After exceeding a reduced flight test schedule in the first\nquarter, the Lockheed Martin F-35 programme faces new delays barring a strong\npush during the final week of April.

Lockheed and government pilots beat a 29-sortie flight test\nschedule during the first quarter, completing 33 flight tests from 1 January to\n31 March, Lockheed Martin chief executive officer Bob Stevens told analysts\nyesterday.

But the pace of flight tests stalled in the first three\nweeks of the second quarter, with only five sorties completed through 21 April,\nsays Stevens, during the company's first quarter earnings teleconference.

April was expected to be a key month for the flight test\nprogramme. After averaging one sortie almost every three days from January to\nMarch, the programme planned to complete 29 flight tests in April alone, or\nnearly one a day.

With nine days remaining on the calendar, Lockheed faces a\ntough challenge. The programme needs to average about 2.5 sorties per day\nthrough the end of April to remain on schedule.

Among the flight tests scheduled in April is the first\nflight of the CF-1, the first F-35C carrier variant to join the flying test\nfleet. In a hearing two weeks ago, senators singled out the completion of CF-1 first\nflight before May as a key milestone for proving the programme is back on\ntrack.

Under the latest revised schedule, the programme expects to\ncomplete 400 flight tests overall in 2010. A previous version of the schedule in\neffect until earlier this year called for completing more than 1,200 flight\ntests during the same period. Lockheed, however, is running at least six months\nbehind on delivering flight test aircraft.

The second F-35A variant - AF-2 - completed its first flight\non 20 April (shown pictured), becoming the 7^th aircraft to enter flight tests.\nLockheed has already retired one flying aircraft - AA-1 - for live-fire testing.

Stevens cautioned analysts from making \"hyperbolic\"\nreactions to any new minor delays in the flight test programme.

\"I think there are going to be some periods where we do\nbetter than planned and some periods where we don't do as well as planned,\"\nStevens says, \"but my goal here is to look at the long-term trend and\nopportunities and make sure we're responding properly.\"