The U.S. Defense Department and weapons manufacturer Lockheed Martin finalized a $34 billion contract for the delivery of 478 advanced F-35 fighter jets, the sides announced Tuesday.
It is the largest contract to date for the fifth-generation aircraft, and includes 291 jets for the U.S. military, 127 for the program's international partners and 60 allocated to foreign military sales.
The project has long been dogged by astronomical cost-overruns and technological set-backs, and in announcing the new agreement the Pentagon hailed the reduced costs in the newest order, calling them "critical to the success of this program."
"This agreement achieves an average 12.7 percent cost reduction across all three variants and gets us below $80 million for a USAF F-35A by Lot 13 - one lot earlier than planned," Air Force Lt. Gen. Eric Fick, the F-35 program's executive officer, said in a statement.
The F-35A is the conventional take-off and landing variant designed for the U.S. and other air forces.
The price tag for the B variant, which allows for short take-offs and landings, will remain above $100 million for the three lots of orders included in the contract. The C variant with its larger wing-span is expected to dip below $95 million per unit by the time the delivery of the final tranche is completed, according to information provided by Lockheed and the Pentagon.
The contractor and the department estimate total cost reductions to sit at 12.8% by the time the contract is fulfilled.