Rolls-Royce is pitching the BR725 for the US Air Force’s B-52 bomber re-engine effort, though the service has yet to establish a programme of record or release a request for proposals.
Momentum has increased on the engine replacement as more responses to the USAF’s B-52H engine alternative study have poured in, says Tom Hartmann, R-R North America’s senior vice-president of customer business. Despite an accident in January that dropped one TF33 engine from a bomber during a training mission, R-R has no sense has no sense of when an RFP could drop or whether the USAF could fit the engine replacement in its budget.
“We’re acting like it’s imminent, those are the grindstones we’re working,” Hartmann says. “I think there’s been a sense of urgency for a couple years now. The reason we’re doing this today is because we’re seeing an increased momentum and want to offer our best shot at the competition.”
Without a firm RFP in hand, R-R is basing its initial BR725 offering on discussions with the service and B-52 manufacturer Boeing. R-R clarified the company is not teaming with Boeing.
R-R's 700-series engines are part of the USAF’s F130 engine family, powering the service’s Bombardier Global 5000-based E-11A Battlefield Airborne Communications Node aircraft and the Gulfstream G550-based C-37A. If the USAF moves forward with engine replacement and R-R wins the contract, the company would create a new F130 engine assembly and test line in the US, while production of commercial variant, the BR725, would continue in Germany. R-R's primary engine assembly site in the US is the former Allison complex in Indianapolis. R-R also produces subassemblies in a plant in Richmond, Virginia.
So far, the USAF has foregone plans to reconfigure the B-52s with four engines, which would have required expensive modifications to the wings, R-R says. R-R previously considered a higher thrust variant of the RB211 turbofan engine as a four-engine option on the B-52, but the service does not appear to be moving in that direction, according to R-R.
“Our BR700 is right in the sweet spot,” Hartmann says. “It’s almost a perfect one-for-one fit from a thrust and a size standpoint.”
While rival engine manufacturer Pratt & Whitney has touted an upgraded version of its original TF33 engine to sustain the B-52 through 2050, R-R cites support from both Boeing and the USAF for a replacement rather than refurbishment, Hartmann says. The new engines would require a reduced number of air refueling tankers, would avoid obsolescence risks older engines could pose and could provide a 34% improvement in fuel consumption over existing engines, he says.
“Refurbishing the engines only gives you a partial benefit,” he says. “So you may see initial lower costs, but it’s a $10 billion increase in fuel costs and overhauls over the life of the fleet.”