Lockheed Martin has found a way to fix the F-35 Lightning II’s fuel dump system, eliminating a potential fire hazard, a top company official said.
“We expect to have that configuration change back in the test airplane early this year,” said Tom Burbage, Lockheed’s Joint Strike Fighter program manager. “The permanent modification that will go into all the production airplanes will be tested by the second quarter of this year.”
The current test aircraft fleet has an interim solution installed, Burbage said.
In conventional aircraft, fuel can be dumped through a mast that ejects the fluid away from the aircraft’s surfaces. But to keep the F-35 stealthy, the design pumped fuel out forcefully from a valve that is flush with the wing, Burbage said. This design allowed a portion of dumped fuel to move back toward the aircraft’s structure. On the Marine Corps’ F-35B version of the aircraft in particular, the fuel could flow too close to the roll-post ducts, part of the short-takeoff-and-vertical-landing system, and potentially ignite.
The problem came to light in a November report to acting Pentagon procurement czar Frank Kendall compiled by the Defense Department’s top operational tester, J. Michael Gilmore.