In yet another step towards updating the B-52 bomber, used by the US Air Force, Boeing has defined that an auxiliary power unit (APU) manufactured by Honeywell.
The APU selected is a GT 36-150 model, and will be integrated into the aircraft's new electrical power system, as well as new Rolls-Royce engines to command a pneumatic start.
Currently, the B-52 is not capable of starting the TF-33 engines through the APU, normally an external unit is used (LPU), or through the archaic Cart Start system, of gunpowder cartridges that explode, as in the video below.
“The B-52 is one of the most enduring USAF aircraft, ensuring force readiness against emerging threats”, said Dave Marinick, president of Honeywell Aerospace's Engines and Power Systems Division. “We are confident that our proven APU 36-150 will exceed USAF expectations throughout the CERP contract and subsequent B-52 active squadron service that will last until at least 2050.”
The US Air Force (USAF) has 72 B-52H bombers, all equipped with eight Pratt & Whitney TF33 engines, a military version of the JT3D used in the 707. The manufacturing of the engines ended in 1985 and, according to USAF studies, they will not have more maintenance conditions from 2030.
For this reason, and also to expand the operational capacity of bombers until 2050, the B-52 is undergoing a major modernization.
a year ago Rolls Royce selected to supply 608 F130 engines, outperforming offers from Pratt & Whitney and General Electric.
It is a military version of the BR700 used in executive jets such as the Bombardier Global Express and Gulfstream G650. The engines will be manufactured by Rolls Royce, while the integration into the jet will be carried out by Boeing. The Rolls Royce F130s will give the B-52 more efficiency, ease of maintenance and less dependence on tankers.
The new turbofan engines are larger than the current TF33, which led to the design of new nacelles, manufactured by Spirit AeroSystems. According to aerodynamics engineer Mike Seltman, the larger nacelles are closer to the wing. This, he says, “It brings up interesting aspects in of controllability, so we are doing the wind tunnel test: to make sure we have all of that covered.”
The USAF hopes to have its first B-52s with new engines by 2027, with a view to obtaining Initial Operational Capability in 2030. In addition to the F130s, the bombers will also receive a new electronic warfare suite, AESA APG-79 radar (the same as the F/A-18 Super Hornet), modifications to the avionics and even the crew configuration. With such extensive modernization, the planes will have another name: B-52J or B-52K.
