The Pentagon may be willing to back off its plan to build more than 2,400 F-35 stealth jets, says Gen. Joseph Dunford, the president's nominee for chairman of the Joint Chiefs of Staff. Dunford's remarks to a Senate subcommittee coincided with new questions about whether Lockheed Martin's F-35 Lightning, set to become the U.S. military's signature new fighter, will be worth the investment.

The F-35 was condemned in a scathing internal report from an Air Force test pilot, published for the first time last week by War Is Boring. The report revealed that the F-35 was outgunned and outmaneuvered in a test dogfight against the much older F-16 Fighting Falcon during exercises over the Pacific this year. Lockheed responded by asserting that the F-35 is a capable long-range fighter, which multiple sources told War Is Boring is either exaggeration or obfuscation.

Dunford, considered to be a shoo-in as the head of the president's military advisory board, told the Senate Armed Services Committee the Pentagon's plan to build 2,443 F-35s is under review. Developing and buying the jets is expected to cost $400 billion, according to Defense One, with operation and maintenance expected to cost an additional $859 billion to $1 trillion. The astronomical costs come as the military has increasingly relied on drones and other advanced technology to address nontraditional adversaries like ISIS.

“Given the evolving defense strategy and the latest Defense Planning Guidance, we are presently taking the newest strategic foundation and analyzing whether 2,443 aircraft is the correct number,” Dunford wrote in a response to questions asked by the committee. “Until the analysis is complete, we need to pursue the current scheduled quantity buy to preclude creating an overall near-term tactical fighter shortfall.”