While F-35 prime contractor Lockheed Martin touts the “blueprint for affordability” that since last year has helped it shave costs from its manufacturing processes, engine supplier Pratt & Whitney has waged its own “war on cost” since 2009. From the time it built the sixth flight-test engine to those it is producing today, the engine manufacturer claims to have reduced the cost of the F135 turbofan by 55 percent.

Pratt & Whitney does not disclose the unit cost of the three F135 engine variants, describing that information as “proprietary and competition sensitive.” In October, the manufacturer signed procurement contracts with the U.S. Department of Defense (DOD) for the seventh and eighth low-rate initial production (LRIP) lots. LRIP 7 had a procurement contract value of $680 million for 36 engines, which by simple division would be $18.8 million per engine if all engines were the same. The procurement cost of LRIP 8 was $793 million for 48 engines, or about $16.5 million per engine. The total cost of LRIP 7 was $943 million with sustainment contract included; for LRIP 8 it was $1.052 billion.

The manufacturer tracks its progress on a cost curve that starts with the sixth flight-test engine, or FTE-6, as the baseline. “We have a curve that defines how our price will change unit by unit up through the 300th unit. It’s a prescribed cost reduction,” said Mark Buongiorno, Pratt & Whitney F135 program vice president. “We identify specific tasks, we work those tasks to closure and validate the changes to make sure they meet the engineering intent of the product.”

As of March 31, Pratt & Whitney had delivered 217 F135 engines to Lockheed Martin in Fort Worth and to the Cameri Final Assembly and Check-Out facility west of Milan, Italy, which is assembling F-35s for that country and the Netherlands. While it has committed to the F-35 Joint Program Office (JPO) to deliver the F135 based on the cost curve, the manufacturer is not currently tracking exactly to the curve in building the engine, acknowledged Buongiorno, who was appointed program vice president in February. “Right now we’re slightly behind the projection,” he said. “We’re slightly over relative to what we’re recognizing as actual cost, but we have signed up to a delivery price to the JPO that is on the curve…We are very motivated to keep marching down the path of the flyaway price for the engine.”

Pratt & Whitney’s goal by the 300th engine is to match the price of the F119-PW-100 turbofan that powers the F-22 Raptor, from which the F135 engine is derived. It notes that the F135 is 20 percent larger than the F119. As of early April, the manufacturer was awaiting the government’s response to its proposal for LRIP 9, consisting of 60 engines, and LRIP 10, for 100 engines. Pratt & Whitney hopes to sign a contract around October, Buongiorno said.

The F-35 program selected acquisition report (SAR) the DOD released in March estimates the overall cost of the F135 engine subprogram will decline by $1.6 billion—or 2.3 percent—to $67 billion. The Pentagon attributed this to revised inflation estimates, reductions in initial spares requirements due to the maturation of the engine and revised estimates based on actual costs of early LRIP lots. The DOD also reduced its estimate of the overall cost of procuring F-35s by about 2 percent to $391 billion in the SAR, which is updated annually.