GE Aviation, Raytheon Technologies’ Pratt & Whitney unit, and Rolls-Royce have all said they will compete.
On May 19, 2020 the US Air Force (USAF) issued its request for proposal (RFP) on the B-52H Commercial Engine Replacement Program (CERP), calling for responses by July and a contract award expected in June 2021.
CF34-10s, which powers commercial aircraft like Bombardier and Embraer regional jets, and Passport turbofans, which power Bombardier’s Global 7500 business jet are the two engines that GE Aviation plans to offer. The PW800 engine, which powers Gulfstream G500 and G600 business jets, is the engine that plans to offer Pratt & Whitney. Finally, R-R plans to offer the F130 engine (shown in the main image of this post), a military derivative of the company’s BR700, which is also the engine of Gulfstream business jets and other aircraft.
A total of 608 engines plus additional spare engines and support equipment are required. They are to be delivered over 17 years. For prototyping purposes, USAF will start with 20 engines—16 for two aircraft plus four spares.
The program office assesses “significant risk” in “integrating current technology commercial engines on the 1950s-era B-52 aircraft technology,” according to justification documents. According to Air Force Magazine, the heavily-redacted documents conclude that GE, Pratt, and Rolls are likely to be able to meet service requirements. Two other companies—their names redacted in the documents—“did not submit a viable solution” for the requirement.
The USAF’s B-52Hs’ engines are the Pratt & Whitney TF33-PW-103s which have powered the aircraft since the early 1960s. The TF33 is based on the commercial JT3D that powered the Boeing 707 and Douglas DC-8. Each Stratofortress has eight engines.
The USAF is looking for a replacement engine that has a similar size, thrust and weight compared to the legacy P&W powerplants. Each of those engines generate 17,000lb-thrust (75.7kN). The service also wants a modern turbofan with a higher bypass ratio and digital engine controls. It wants that engine to have reduced fuel consumption, noise, emissions and operating costs.
The Air Force has said that it expects fuel savings will pay for the cost of the re-engining program, which would also drive a reduction in maintainers assigned to the airplane. With the fuel efficiency, USAF is also looking for an increase in persistence or range of up to 40 percent.
The re-engining is the centerpiece of an overall B-52 technology refresh that will also include new radars, connectivity enhancements, and capability for new weapons, such as hypersonic missiles. Boeing, the original prime on the B-52, will handle integration of the new engines.
The B-52 is slated to remain in service through 2050.
Photo credit: U.S. Air Force