Inspectors have found a small crack in one of the wing spars of an F-35C carrier variant test aircraft, 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.
Compared to the F-35A, the F-35C carrier variant features larger wings with foldable wingtip sections, larger wing and tail control surfaces for improved low-speed control, stronger landing gear for the stresses of carrier arrested landings, a twin-wheel nose gear, and a stronger tailhook for use with carrier arrestor cables. The larger wing area allows for decreased landing speed while increasing both range and payload.
The United States Navy intends to buy 480 F-35Cs to replace the F/A-18A, B, C, and D Hornets and complement the Super Hornet fleet.
The test aircraft is being used in what’s called “durability ground testing”, a normal test programme in which testers apply loads to the airframe to simulate operational flying and identify any potential problems. Such discoveries are expected during a developmental test programme.
Joe DellaVedova said:
“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.”
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 aircraft 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.