Crack Discovered on F-35C Test Plane Wing Spar

By Lara Seligman

WASHINGTON — Inspectors found a small crack in one of the wing spars of an F-35C carrier variant test plane, according to the Joint Program Office.

The discovery does not impact current F-35 flying operations, and will not affect the Navy’s ability to meet its planned initial operating capability date in August 2018, JPO spokesman Joe DellaVedova told Defense News Monday.

The test plane is being used in what’s called “durability ground testing,” a normal test program in which testers apply cyclic loads to the airframe to simulate operational flying and identify any potential problems.

Such discoveries are expected during a developmental test program, DellaVedova stressed.

“The purpose of durability testing is to intentionally stress the aircraft to its structural limits so we can identify any issues and corrective actions needed to fix them,” he said.

This type of testing will ensure the F-35’s requirement for 8,000 flight hours, DellaVedova noted. During durability tests, the plane is tested to two lifetimes, or 16,000 flight hours, he explained.

The test plane with the crack had more than 13,700 test hours, which equates to 6,850 flight hours — or more than 20 years of operational flying, DellaVedova emphasized.

The government and industry teams are working to find an engineering solution, he noted. One potential fix includes a modification of approximately a half pound to the aircraft. The fix will be incorporated to the rest of the fleet.

The plane has 13 wing “spars,” which are the main structural members of the wing.