The Defense Department’s F-35 Joint Program Office awarded Pratt & Whitney a $1.4 billion contract for lot nine low-rate initial production (LRIP) of  the F135 propulsion system to power the F-35, the company said Tuesday.

The LRIP 9 contract covers 66 total production engines and also includes spare engines, spare modules, spare parts for the field. The contract also includes program management, engineering support, production non-recurring effort, and tooling.

Pratt and Whitney highlighted the F135 engine maintains a 96 percent full mission capability requirement and that new engine reliability exceeds 90 percent, which is ahead of key 2020 requirements.

These contracted engines are divided between 53 conventional takeoff and landing (CTOL) and 13 short takeoff and vertical landing (STOVL) propulsion systems. They are being produced for the U.S. Air Force, Navy, and Maine Corps as well as five partner countries: Italy, Norway, Israel, Japan, and the United Kingdom.

“The latest agreement with the F-35 Joint Program Office continues a reduction in costs associated with engine production, and demonstrates our commitment in providing affordable and dependable propulsion for the global F-35 program,”” Mark Buongiorno, vice president of the Pratt & Whitney F135 engine program, said in a statement.

“We remain laser-focused on reducing costs, meeting our delivery schedule commitments, ensuring dependable engine performance, and preparing for global sustainment of the F-35 fleet,” he added.

Production of the first LRIP 9 engine is underway, with deliveries schedules to start in the second quarter of 2016, Pratt & Whitney said. The company is also working with the joint program office to finalize details of LRIP 10 engine production and expects that contract to be awarded by the end of this month.

Pratt & Whitney is a division of United Technologies [UTX].