WASHINGTON – On-the-ground stress testing for the Marine Corps version of Lockheed Martin Corp.’s F-35 jet may be halted for as long as a year after cracks were found in the aircraft’s bulkheads, Pentagon officials said.
Testing of the fighter’s durability was stopped in late September after inspections turned up cracks in three of six bulkheads on a plane used for ground testing, said Joe DellaVedova, spokesman for the F-35 program office.
The previously undisclosed suspension of the stress testing may increase scrutiny of the Marine Corps’ F-35B, the most complex of the three versions of the plane, during congressional hearings on the Defense Department’s fiscal 2015 budget. The department plans to request funds for 34 F-35s, eight fewer than the 42 originally planned, according to officials. Six of those planes would be for the Marines.
We consider this significant but by no means catastrophic, Frank Kendall, the Pentagon’s undersecretary for acquisition, said in an emailed statement. While the program office is still performing an assessment, based on preliminary analysis, a redesign of some F-35B structures will be required, Kendall said.
Michael Gilmore, chief of the Defense Department’s weapons testing office, said in his annual report last month that during ground testing in late September, the cracks continued to grow until a bulkhead severed and transferred loads, which caused cracking in the adjacent bulkhead.
The cracking is significant enough to warrant changes to the design of the bulkhead, Jennifer Elzea, spokeswoman for the Pentagon test office, said in an email. This is a new defect that must now be addressed through a production change and a retrofit plan.
We can’t know all the changes that must be made to the structures until the testing is complete, and it is not surprising when discoveries like this occur, she said.