By Marina Malenic
Flights have resumed for seven of the 10 F-35 Joint Strike Fighter test aircraft grounded after a generator failure last week, the Pentagon said yesterday.
AF-4, a System Development and Demonstration (SDD) aircraft, experienced a dual generator failure and oil leak while conducting flight test operations March 9 out of Edwards AFB, Calif., the F-35 Joint Program Office has previously said (Defense Daily, March 14). As a safety precaution, operations were suspended beginning on March 10.
Since the incident, the JPO, the Air Force and Navy System Commands and prime contractor Lockheed Martin [LMT] have collaborated to determine the root cause, according to JPO spokesman Joe DellaVedova. As of press time, that process was still under way.
“The failed generators from AF-4 were inspected over the weekend,” DellaVedova said via e-mail. “On the basis of that effort, and in combination with flight test data from the incident, it was determined that the dual generator failure was the result of a design artifact unique to a newer configuration of the generator.”
The F-35 fleet has two generator configurations. The newer generator is in place on test aircraft AF-4, BF-5, and CF-1, according to DellaVedova. Aircraft flying the older generator configuration–AF-1/2/3 and BF-1/2/3/4–were permitted to fly as of March 14, Vice Adm. David Venlet, the F-35 program manager, said yesterday during a House Armed Services Committee hearing. The grounding continues for the balance of the SDD fleet and all Low Rate Initial Production (LRIP) aircraft, as they are configured with the newer generator.
Two F-35 production-model jets–AF-6 and AF-7–flew for the first time in recent weeks (Defense Daily, March 8). The grounding also affects their operations, DellaVedova has said.
Meanwhile, software development for the program is “significantly” behind schedule just as it is entering its “most challenging” stage, congressional auditors said during House Armed Services Committee testimony.
“Each of the remaining three [software] blocks are now projected to slip more than three years,” Michael Sullivan, the director of acquisition management for the Government Accountability Office, told lawmakers. The final block had been expected this year, according to the schedule set in 2006, but will not be completed before 2015, Sullivan said.
The blocks are progressively more complex versions of the software that contain the airplane’s elaborate mission systems.
GAO’s annual report on the program, which contains these and other findings, was also released yesteray. Among the findings, the program to buy 2,457 aircraft by 2035 will cost some $11 billion annually.
Defense Secretary Robert Gates earlier this year delayed purchases of 242 aircraft over the five-year development period remaining and shifted $4.6 billion into that effort under a massive program restructure.
“Officials underestimated the time and effort needed to develop and integrate the software, substantially contributing to the program’s overall cost and schedule problems, testing delays and requiring the retention of engineers for longer periods,” the new GAO report states said.
“After more than nine years in development and four in production, the JSF program has not fully demonstrated that the aircraft design is stable, manufacturing processes are mature, and the system is reliable,” it reads. “Engineering drawings are still being released to the manufacturing floor and design changes continue at higher rates than desired. More changes are expected as testing accelerates.”