Why You Do Test:

A fault in the first F-35 flight test aircraft produced a serious situation that the airplane recovered from so smoothly that the pilot barely detected it, Lockheed Martin test director Doug Pearson said in an interview at AFA’s Air Warfare Symposium in Orlando Friday. During a test hop, an arc in an electro hydrostatic actuator caused a short circuit that disabled a flight control surface. The faulty part had been made too thin and without sufficient resistance. Flight control software detected the fault instantly and within a half second, trimmed the airplane to compensate, Pearson said. The problem pointed up the need to redesign the actuators and caused a delay in testing, but it was the kind of thing that “we never would have tested for in the air,” Pearson noted. It also illustrated the F-35’s ability to tolerate something akin to battle damage and keep on flying. The glitch was a headache to fix, but offered reassurance that flight controls work well, he said. Lt. Col. James Kromberg, first USAF pilot to fly the F-35, said he flew the F-35 simulator 150 hours before flying the real thing, and noted that the genuine article very closely matches the performance predicted in the simulator. The F-35 is already cleared to 4Gs, 33,000 feet, and 20 degrees angle of attack.