The Air Force released May 19 the final request for proposals for industry to build the B-52H Stratofortress’ new propulsion system.

The Commercial Engine Replacement Program (CERP) will replace engines on the service’s fleet of 76 B-52H aircraft, manufactured in the 1960s. The goal of the program is to keep the “Buff” flying past 2030 and into the 2050s as the service looks to use it to carry multiple new weapon systems, including hypersonic missiles and the Long-Range Standoff (LRSO) cruise missile.

The winning engine developer will build 608 new commercial engines, plus provide additional spare engines and other support equipment and data over a 17-year performance period. That includes one six-year basic period, one five-year option period and six one-year options, currently slated for fiscal year 2021 through FY 2035.

Responses are due July 22, with all questions due June 2, per the solicitation released on the Defense Department’s beta SAM website. Contract award is currently expected in November 2020, with initial prototypes flying by 2025.

Pratt & Whitney [UTX], Rolls Royce and GE Aviation [GE] are vying for the lucrative contract. Pratt & Whitney is pitching its PW815 engine to replace the current P&W-made TF33-PW-103s on board the aircraft. Rolls-Royce will submit its F130 engine for the competition, while GE Aviation will offer two engines: the CF34-10 and the Passport. Boeing [BA], the aircraft manufacturer, is serving as sole-source integrator for a wide array of B-52 modernization efforts in the works, to include a new radar, internal weapons bay upgrades, communications network and various electronics upgrades.

The Air Force requested $299.4 million in research, development, test and engineering (RDT&E) funds for the B-52 reengine program in the fiscal year 2021 presidential budget request released in February. The service has budgeted nearly $1.3 billion for the program across the five-year Future Years Budget Plan (FYDP), according to service documents. The Air Force has spent about $235 million over the past two fiscal years on the CERP, and expects to spend $7 billion to $8 billion over the program’s lifetime, officials have previously said.