The revision of the estimate was first reported by Bloomberg news.
The cost per flying hour of the F-35B model, which can land like a helicopter, is likely be 16.6 percent lower than the earlier Pentagon projections, Lieutenant General Robert Schmidle, deputy Marine Corps commandant for aviation, told Reuters in an interview on Wednesday.
The Marines plan to start using the F-35B for military operations from mid-2015.
A second senior defense official said the current estimate by the Pentagon’s Cost Assessment and Program Evaluation (CAPE) office put the cost per flying hour of the F-35B model at over $41,000, but the actual cost would likely be closer to $37,000.
A detailed analysis by the Marine Corps showed this would cut the plane’s annual operating costs by nearly $600 million, or $12.3 billion over the next five decades, the official said.
Schmidle said the Marines would fly the planes in short takeoff, vertical landing, or STOVL mode just 10 percent of the time, far less often than the 80 percent rate factored into the initial estimates. The manning levels assumed in the initial estimates were also higher than in practice, he said.
“The Marine Corps has very aggressively stepped out in trying to find ways to decrease the operating and support costs, specifically with regard to the cost per flight hour,” Schmidle said. “I wanted to challenge every assumption.”