Software problem doesn't sound like it will cause much of a delay. Depending on the nature of the problem with the hinge - and whether it needs a redesign - this could cause another major delay to the F-35B......
F-35s Grounded for Software, Hinge Fixes
Flight testing of all F-35 Joint Strike Fighter variants has been temporarily suspended until software that controls functioning of the engine's three fuel boost pumps is modified, the Pentagon said Oct. 1.
In addition, short takeoff/vertical landing-mode flight testing operations have been prohibited for the F-35B variant after post-flight inspections revealed an issue with the auxiliary inlet door hinge on test aircraft BF-1, said Lockheed Martin spokesman John Kent.
The auxiliary inlet doors, located immediately aft of the lift fan, open to feed additional air to the engine during short takeoffs, vertical landings, hovers and slow-speed flight, Kent said.
The software problem that grounded all three jet variants and led to incorrect sequencing was discovered during laboratory testing, Pentagon spokeswoman Cheryl Irwin said. Left uncorrected, she said, "This could have possibly triggered a shutdown on the three boost pumps, which could potentially cause an engine stall."
Irwin said that such a simultaneous shutdown would be highly unlikely but that "prudence dictated a suspension of operations, temporarily, until the fuel boost pump signal timing was corrected."
Irwin said that update of the software that controls the functioning of the three boost pumps has been developed and that Lockheed engineers plan to complete functional and safety tests prior to installation in the test aircraft. Kent said the update, developed in partnership with fuel system software developer BAE Systems, will be delivered this weekend.
Flight testing will resume Oct. 5, Irwin said.
Kent said F-35B STOVL-mode flights will resume after the root cause has been identified and corrected.......