Washington – Federal investigators said Wednesday that Pratt & Whitney’s engine for the F-35 Joint Strike Fighter still is “not performing at expected levels” and is one of many glitches still plaguing the nation’s next generation of fighters.
“While Pratt & Whitney has implemented a number of design changes that have resulted in significant reliability improvements, the F-35A and F-35B engines are still at about 55 percent and 63 percent, respectively, of where the program expected them to be at this point,” said the report by the Government Accountability Office.
The F-35A is the Air Force version of the plane, and the F-35B is the Marine Corps version, which is capable of short takeoffs and vertical landings. There is also an F-35C Navy version designed for carrier operations.
Reacting to the GAO report, Pratt & Whitney spokesman Bradley N. Akubuiro said, “The F135 engine has accumulated over 50,000 engine flight hours, maintains an average fleet readiness metric of 95 percent and is already exceeding key year 2020 spec requirements in support of the F-35.”
He also said the reliability of the engine, known as the F135, has nearly tripled since the GAO issued a critical report on the engine about a year ago.
“Additionally an independent assessment of F135 engine reliability conducted by RAND concluded that F135 engine reliability is improving with each subsequent production lot as new designs and improvements are being incorporated into production and fleet engines,” Akubuiro said.
In 2014, problems with an engine seal caused a fire that temporarily grounded the F-35 fleet.
The GAO report said “problems with the engine seal were addressed through a design change that was incorporated into production, and as of September 2015, 69 of 180 engines had undergone retrofits.”
Other problems with the Joint Strike Fighter program were cited by witnesses at a House Armed Services hearing Wednesday.
“Overall, the program is at a critical time,” said Michael Gilmore, head of the Pentagon’s Operational Test and Evaluation Office. “Although the Marine Corps has declared Initial Operational Capability, and the Air Force plans to do so later this calendar year, the F-35 system remains immature and provides limited combat capability, with the officially planned start of Initial Operational Test and Evaluation just over one year away.”
Gilmore said, “The program is working to resolve the many issues it confronts, but my assessment is that the F-35 program will not be ready for combat testing until mid-2018 at the earliest,” about a year later than planned.
Cybersecurity weaknesses in Lockheed Martin Corp.’s F-35 are among “many unresolved deficiencies” plaguing the F-35 as production of the fighter jet ramps up, Gilmore said.
As far as the F-35’s engine, testimony from Michael Sullivan of the GAO said “engine manufacturing deliveries remain steady, and 218 engines have been delivered to date. “
“The labor hours required for assembling engines has remained steady and very little additional efficiency is expected,” he said. “As a result, Pratt & Whitney is looking for additional ways to save cost.”
Because of budget constraints, the Air Force has cut five F-35s in next year’s budget and 45 of the fighters over the next 10 years.
The GAO report also said that “although the F-35 total program acquisition costs have decreased since 2014, the program continues to face significant affordability challenges.”
Although some lawmakers have suggested extending the life of the F-22 and older “legacy” aircraft while slowing production of the F-35s, witnesses said that would cost the Pentagon more money in the long run.
Air Force Lt. Gen. Christopher C. Bogdan, the head of the Joint Striker program at the Department of Defense, said, “Our legacy fighters will not survive the challenges that they face.”
He conceded, “We’ve had a past that is not conductive to people believing in what we say,” but assured lawmakers the F-35 program is on track.
He said to date 172 aircraft have been delivered to test, operational and training sites.
Sean Stackley, head Of the Navy’s office of research, development and acquisition, also defended the program.
“The F-35 is on a path to deliver what was promised from day one,” he said.