F-35 Testing Progresses; UK Rethinks Switch to F-35C
Lockheed Martin has described progress in the F-35 development program, and solutions to some of the problems that have recently been identified. Having exceeded the planned flight-test sorties and test points in 2011 by 15 percent, the company is hoping for similar gains this year. Of the 59,585 test points scheduled for the development phase through 2016, just over one-fifth had been flown by the end of December. F-35A models have reached the maximum speed of Mach 1.6, and an altitude of 43,000 feet. The Block 2A software is now flying on the aircraft, three months behind schedule. Lockheed Martin vice president of F-35 customer engagement Steve O’Bryan noted that Block 2 contained seven million lines of code, and there “had not been a single abort” of an F-35 flight due to software.
O’Bryan said that the jitter and latency problems in the VSI helmet-mounted display are being solved. The helmet’s night vision deficiency will be fixed by relocating the camera from the top of the helmet to the exterior of the aircraft, just forward of the canopy. The transonic buffet issue can be addressed through changes to the flight control system software. The fuel dump problem on the F-35B will probably be solved by a tighter seal on the flaps that will prevent dumped fuel from pooling in that area. The arrestor hook on the F-35C is being sharpened at the shank, and the hold-down damper is being modified. This combined solution should ensure that the hook catches the wire, O’Bryan said. But the hook problem has probably delayed the first F-35C test flights on a carrier from late 2013 into 2014, he added.
External weapons–AIM-9X AAMs on the outer wing stations–were flown for the first time last month on an F-35A operating from Edwards AFB. O’Bryan said that weapon separations will start this summer. Meanwhile, the six production F-35As already delivered to the training base at Eglin AFB started flying on March 6, although the first sortie was cut short by a fuel leak indication. The first three production F-35Bs for the U.S. Marine Corps were delivered to Eglin in January.
In the UK, the Ministry of Defence is reconsidering its late 2010 switch from the F-35B STOVL to the F-35C CV version. A decision is due shortly. Last November, the MoD said it preferred the F-35C because of its longer range, greater payload and lower acquisition cost than the STOVL version, as well as greater interoperability with allies. But it seems the rethink has been prompted mainly by the escalating projection of the cost of converting one of the UK’s new aircraft carriers, now being built, for “cats-and-traps.” The estimate that informed the original decision to switch was about $750 million for a steam catapult system or $1.8 billion for the new electro-magnetic aircraft launch system (EMALS). It is now $1.2 to $1.8 billion or more. Shortly after the UK switched models, the F-35B was put “on probation” by the Pentagon due to various technical problems, but this measure was rescinded last January.