F-35 Ground Ops Resume

Eight days after F-35 operations were suspended due to an Integrated Power Package failure on aircraft AF-4, ground operations have resumed on developmental test aircraft, the F-35 Joint Program Office said Aug. 11. “This is the first step in returning the F-35 fleet to full flight operations,” a JPO spokesman said. A government/contractor team has made a preliminary finding that a control valve malfunctioned, causing the IPP to fail. The IPP is similar to an Auxiliary Power Unit in that it provides start-up power to the engines and also provides internal cooling for the aircraft. The ability to monitor this valve is “the mitigating action” allowing ground testing to resume, the spokesman said. “Further reviews are necessary” before returning the 20 F-35s in flight status to airborne operations, he added, noting that “margin” has been built into the test schedule to accommodate incidents such as this. No estimate was provided as to when the F-35s will resume flying. (JPO release)