On May 19, 2020, the U.S. Air Force released a request for proposals to replace the TF33 engines powering the B-52H Stratofortress bomber fleet with 608 new engines, in a contract running up to 17 years. The request does not give a dollar value for the contract, but the Air Force had previously estimated the cost at $1.4 billion from FY2019 to FY2023.
The Air Force currently operates 76 B-52Hs, the most recent of which was built in the 1960s. The Air Force now expects to operate them until 2050. The last TF33 engine was built in 1985.
The re-engining effort (officially the Commercial Engine Replacement Program, or CERP) had been anticipated for some time, as the Air Force had announced its plans to extend the B-52s’ service into at least the 2040s, and had held an industry day on December 12, 2017, to share information and solicit vendors for the program. Boeing, the B-52 prime contractor, even produced an animated video touting the benefits of re-engining.
The solicitation calls for engines that are military-specific derivatives of existing commercial engines. Given the specification that the eight engines on each B-52 were to be replaced by eight new engines (as opposed to, perhaps, four larger engines), the expected candidates are variants of engines currently used for business jets and regional airliners, as those best approximate the physical size of the TF33s to be replaced while offering considerably improved fuel efficiency. CERP’s principal goals are to reduce the fuel cost of operating the B-52 fleet while increasing reliability.
The engines under consideration provide similar thrust to the existing TF33s but are based on much more recent designs. Also, as their commercial versions are in current service around the world, they can be supported more easily using the commercial logistics infrastructure. Most commercial equivalents of the TF33 have been retired, as have most TF33s used in other Air Force aircraft.
Potential vendors had already placed their candidate engines on display at public conferences, and are believed to include:
-- GE Aviation (Evendale, OH), offering variants of the CF34 and Passport engines;
-- Rolls-Royce (Indianapolis, IN) proposing a modified BR725;
-- Pratt & Whitney (East Hartford, CT) with a militarized PW800.
Proposals are due to the Air Force by July 22, 2020, with the contract to be awarded in June 2021. Initial engines are required to be delivered within 18 months of order.
Click here for the full report (4 PDF pages), on the CRS website.