Pilots Say F-35 Carrier Launch Problem Is Safety Concern
Fleet pilots say the violent vertical oscillations seen during carrier launches of the U.S. Navy’s F-35 variant are a safety concern, even as the Pentagon races to fix the problem. One of the most critical and dangerous phases of flight for Navy pilots is the launch, when an aircraft is shot from the carrier by a steam-driven catapult. For the F-35C carrier variant, pilots discovered a complex problem during recent at-sea testing: excessive vertical oscillations, or a bouncing effect, during takeoff. Pilots who conducted training onboard the carrier USS George Washington during the latest set of ship trials said these oscillations were “a safety concern,” the Director of Operational Test and Evaluation (DOT&E) wrote in its most recent annual report. “Excessive vertical oscillations during catapult launches make the F-35C operationally unsuitable for carrier operations, according to fleet pilots,” DOT&E wrote. Pilots reported the oscillations were so severe that they could not read flight-critical data, DOT&E said. The oscillations caused most pilots to lock their harness during launch, which made emergency switches hard to reach. The pilots deemed this situation “unacceptable and unsafe,” DOT&E wrote. The Navy has informed the F-35 Joint Program Office (JPO) that it considers this problem a “must fix” deficiency. The problem occurs primarily because the mechanism in the nose gear is not “damping out” the oscillations from the cable release quickly enough, JPO Chief Lt. Gen. Christopher Bogdan told reporters during a December round table. “The first thing that happens when those Navy seamen hook the airplane up is they hook the nose gear up to a latching mechanism, and then they pull down and the airplane kind of noses down, all that tension is being held,” Bogdan said. “Then boom! When the cable releases and you start going down the deck, because the airplane has been held down like that the airplane [bounces], and that’s primarily because the mechanism in the nose gear is not damping out the oscillations enough or quick enough.” Bogdan downplayed the problem, saying the oscillations only occur at very light gross takeoff weights. “At medium weights and heavy weights you don’t see this problem at all,” Bogdan said. “If an F-35C is going to combat it is not going to take off lightweight. It’s going to take off with everything it needs to go to combat, so you won’t see that problem.” The Pentagon is currently investigating the best way to fix the problem. One option is to redesign the nose gear, a potentially expensive and time-consuming solution. A long-term mechanical fix is “probably a couple of years off,” so in the meantime the JPO is looking at operational solutions like changing the way a pilot holds on during takeoff, Bogdan said.