F-35 engine manufacturer Pratt & Whitney has started sustainment planning for the aircraft’s F135 turbofan even as F-35s continue flight-testing. “The F135 program is in an interesting place,” Bennett Croswell, Pratt & Whitney Military Engines president, said at a Paris Air Show press briefing on June 19. “We’re in all three phases of the lifecycle of the program. We are still in development; we are producing F135 engines; and now we are in sustainment as well.”
Croswell said the company has delivered 78 engines for low-rate initial production (LRIP) lots 1 through 4, and has started delivery of LRIP 5 engines. Since Pratt & Whitney delivered the first production-representative flight-test engine in 2009, he said, there has been a 40-percent reduction in cost; since the start of the LRIP contracts there has been a 26-percent reduction in cost.
The F-35 Joint Program Office (JPO) recently awarded the company a contract modification for the system design and development program with additional funding of $648 million to continue supporting the F-35 flight-test program through 2016. “Right now we’re executing probably some of the most difficult testing in the flight-test program that we’ve seen,” Croswell said.
Lockheed Martin-built F-35s were temporarily grounded on two occasions earlier this year due to engine-related issues. In January, flight operations of the F-35B short takeoff/vertical landing variant were suspended after engineers discovered an engine fueldraulic line failure. In February, all three variants were grounded after a routine engine inspection revealed a cracked turbine blade in an F-35A based at Edwards Air Force Base, Calif. “Those two issues are well understood and they’re behind us. They’re resolved,” Croswell said.
On the sustainment side, the Air Force recently inducted the first engine at a new heavy maintenance center at Tinker Air Force Base, Okla. The center will be fully operational by year-end. Pratt & Whitney is working with the JPO to determine an overhaul and repair infrastructure; the plan is to have regional centers at Tinker AFB and at Jacksonville Naval Air Station, Fla., where the Navy performs repairs, and in Europe and Asia.
Croswell said the company wants to accelerate the start of a performance-based logistics program with the JPO to 2015, instead of the planned 2019. “If you look at the SAR [selected acquisition report] estimates of what the lifecycle cost is going to be in sustainment of the F135 engine, we believe we can do appreciably better than the SAR estimates,” he said. “We’d be willing to sign up for less than the SAR estimates. And…Pratt & Whitney would be incentivizd to invest ourselves in improvements to the engine to reduce the sustainment costs.”