A small crack has been found in one of the wing spars of an F-35C carrier variant test plane, said the US Department of Defense’s F35 Joint Program Office. Current F-35 flying operations are not impacted by the discovery.
The test plane is being used in durability ground testing, a test program in which cyclic loads are applied to the airframe to simulate operational flying. Running many cycles helps identify any potential problems.
Discoveries such as this are expected during a developmental test program. Durability testing, which is extended to 16,000 flight hours, is designed to ensure the F-35 will meet the requirement for a lifetime of 8,000 flight hours.
The crack occurred on a test aircraft which had more than 13,700 test hours, equal to about 6,850 flight hours – over 20 years of operational flying.
The Joint Program Office says the government and industry teams are working on an engineering solution; one possible fix would be a modification adding about 0.5 lb (0.23kg) to the aircraft.
November 20, 2015