It's taken a bit longer than planned, but the first short take-off and vertical landing F-35B Joint Strike Fighter has fired up its engine. BAE Systems test pilot Graham Tomlinson was at the controls on April 18 for the first ground runs of the Pratt & Whitney F135 powerplant in aircraft BF-1. Lockheed Martin says the tests keep the F-35B on track to fly by late May/early June.Opening doors - F-35B powers up. Photo: Lockheed Martin
It was touch and go for a while after third-stage low-pressure turbine blades in two STOVL engines failed on the test stand because of fatigue caused by high-frequency vibration. But P&W is certain the vibration only occurs at high power in STOVL mode, when the turbine is driving the lift fan. So this particular engine has been cleared for CTOL flying only while P&W fixes the problem. You can read more about the tests in Monday's Aerospace Daily.