While the not mission capable for supply (NMC-S) rate for the Lockheed Martin [LMT] F-35 fighter is to be no more than 10 percent, that rate has been stubbornly high.

NMC-S measures the percentage of aircraft unable to fly because of parts shortages.

In calendar year 2018, NMC-S was 28.6 percent before dropping to 20.1 percent the following year and 15.8 percent in 2020. In 2021, the rate ticked up to 18.6 percent and has increased so far this year to 23.6 percent, the F-35 Joint Program Office (JPO) said.

Parts issues have included delays in supplying power modules for the Pratt & Whitney [RTX] F135 engine, but the F-35 program and industry have apparently mitigated that by ramping up depot capacity. In September last year, 46-48 U.S. F-35As under Air Combat Command did not have a working engine, but that number has dropped to five, Air Force Gen. Mark Kelly, the head of ACC, said this month.

In addition to power modules, parts that have degraded more quickly than expected have included the electro-optical targeting system (EOTS) window cover and canopies, the F-35 program said early this year (Defense Daily, Jan. 25).

The F-35 JPO said that it is focused on decreasing the NMC-S rate “through improving supply posture, repair capacity, and repair velocity and believe outcome-based contracts are the best way to achieve better performance.”

“However, the most relevant of these is by activating our depots (CONUS and OCONUS) in range (activations) and depth (capacity/throughput),” the F-35 program said.

In September last year, Lockheed Martin received the first multi-year sustainment contract for the F-35– a deal worth potentially $6.6 billion over three years (Defense Daily, Sept. 17, 2021).

Under the contract, the company is to receive incentive bonuses by achieving an “up to” 75 percent mission capable (MC) rate for the F-35A and a 61 percent MC rate by fiscal 2023 for the U.S. Marine Corps F-35B and U.S. Navy F-35C.

The F-35 program said that it is updating the F-35 life cycle sustainment plan “with the most current data and is planning on submitting it to OSD in early 2023.”

Last month, Lockheed Martin received a more than $7.6 billion contract for 129 F-35 fighters in Lot 15–49 F-35As; three F-35Bs and 10 F-35Cs for the U.S. Marine Corps; 15 F-35Cs for the U.S. Navy; 32 F-35As and four F-35Bs for non-DoD “participants”; and 16 F-35As for Foreign Military Sales customers (Defense Daily, Aug. 12).

The “Lot 15-16 production contract is not the vehicle used for any industry NMC-S incentive clauses,” the F-35 program said, when asked whether the contracts contain or would contain incentives for Lockheed Martin to reduce the NMC-S rate to 10 percent or below.

“Our current annualized air vehicle sustainment contract does not have NMC-S as an incentive clause,” the F-35 JPO said. “We have other readiness and supply chain metrics aimed at improving readiness and supply chain health.”

The F-35 program said that NMC-S “is a function of enabling supply chain metrics as measured by Gross Issue Effectiveness (GIE – retail supply) and Supply Response Time (SRT – wholesale supply).”

“In order to achieve desired fleet NMC-S needs, the forthcoming F-35 Air Vehicle Demand Reduction Supply Chain performance-based logistics contract will have stringent requirements for GIE and SRT as the two relevant performance incentive fee metrics,” the F-35 JPO said.