The U.S. Department of Defense’s new fleet of F-35 Lightning IIs is making little progress in overcoming its readiness problems, according to a new report by the Pentagon’s chief weapons tester.

“Reliability growth has stagnated,“ Robert Behler, DoD’s director of operational test and evaluation (DOT&E), wrote in his fiscal year 2017 annual report. “Overall fleet-wide monthly availability rates remain around 50 percent, a condition that has existed with no significant improvement since October 2014, despite the increasing number of new aircraft.” 

The Air Force's F-35A conventional variant. Photo: Air Force.
The Air Force’s F-35A conventional variant. Photo: Air Force.

A “notable trend” is that the program has experienced an increase in the percentage of planes that cannot fly because they are awaiting replacement parts, the report adds. In addition, the program is unlikely to achieve its goal for mean flight hours between critical failures “without redesigning aircraft components.”

The findings echo an October report by the Government Accountability Office, which wrote that spare parts shortages and other sustainment problems were hurting the F-35’s readiness (Defense Daily, Oct. 26, 2017).

In a statement on the DOT&E report, prime contractor Lockheed Martin [LMT] insisted that the F-35 is making “steady progress” in development, production and sustainment.

Reliability “continues to improve lot over lot,” the company said. Jets built in the seventh low-rate production lot and later “are averaging greater than 60 percent availability, and some operational squadrons are consistently at or above 70 percent availability.”

Lockheed Martin attributed the improved aircraft availability partly to improved diagnostics in the latest F-35 software upgrade, Block 3F. Older aircraft will be retrofitted with Block 3F.

Lockheed Martin also said it is working with the program office to improve its spares modeling, repair capability and parts ordering to improve the spares inventory and enhance overall readiness.

The company has delivered more than 265 F-35s to the U.S. Air Force, Marine Corps and Navy and foreign militaries. The F-35’s initial operational test and evaluation (IOT&E) is expected to begin late this year and could pave the way for the start of full-rate production.

At a Pentagon press briefing Jan. 25, DoD spokeswoman Dana White told reporters that defense leaders are still reviewing the DOT&E report but continue to have “robust conversations” with the industry team for the F-35, the department’s largest acquisition program. A Pentagon official said in October that DoD was launching a year-long “deep dive” to look for ways to cut the cost of the jet’s production and sustainment (Defense Daily, Oct. 23, 2017).

DoD’s F-35 Joint Program Office said it had no immediate comment on the DOT&E report because its director, Navy Vice Adm. Mat Winter, is traveling outside the United States.