A new US Air Force document released last week outlines the details, timeline and likely competitors for a plan to acquire at least 608 new turbofan engines to replace the eight Pratt & Whitney TF33s on each of 76 Boeing B-52H bombers in the US Air Force fleet.

The air force’s sustainment office for the 17,000lb-thrust TF33 decided last June that the 60-year-old powerplants are not sustainable beyond 2030, due to age, parts obsolescence and a diminishing supplier base, the document says.

P&W has urged air force officials to simply refurbish the TF33, but the document makes clear that approach is not one of the options the air force is considering. Also rejected are previous proposals that offered to cut the B-52H’s engine count from eight to four.

Instead, all three acquisition strategies under review replace all eight TF33s to cut fuel consumption by 20-40%. The new engines must not alter the aircraft’s take-off performance and the weapon release envelope, the document says. The engine replacement also would include revamping the B-52H’s electrical power system, installing new generators and wiring to support new electronics.

The USAF’s three acquisition strategies only differ on the method used to select a replacement engine. One option is delegate the engine selection to an aircraft integration contractor. Boeing was the designer and remains the prime contractor for the B-52H, but the document indicates the company could face competition for the aircraft integration role.

The other two strategies have the USAF selecting the engine contractor after either a one-step competition or a two-stage bidding process.

A notional schedule using the two-stage bidding process indicates the full programme will take 17 years to complete. So far, the USAF has only been awarded seed money in Fiscal 2018 to lock-in the acquisition strategy and release a request for proposals to industry. If the USAF selects a two-stage bidding process, the initial operational capability for the B-52H re-engining would be set for Fiscal 2029, with full operational capability declared five years later.

The prospect of selling more than 600 engines to the USAF has attracted several prospective bidders. In addition to incumbent P&W, Rolls-Royce and GE Aviation attended the air force’s industry day event on 12-13 December in Barksdale, Louisiana, according to the air force’s briefing slides.

Another engine manufacturer, Safran, also attended the event, but it was not immediately clear if the France-based company is interested in supplying engines, nacelles or electrical equipment.

Although the contract opportunity could be lucrative, past experience suggests the air force could still back away from following through with the full programme. One of the briefing slides covers the history of B-52 re-engining projects, with eight prior studies or proposals to replace the TF33s dating back to 1971.

The air force’s recent determination that the TF33 is not supportable beyond the next 12 years may give new urgency to the latest attempt. Although the air force dropped the B-52H fleet from its list of aircraft carrying nuclear glide bombs, the aircraft is still counted as a strategic asset for launching nuclear stand-off missiles, including the forthcoming long-range standoff weapon. Top air force leaders have said the B-52H will likely remain in operation beyond 2050, as the fleet approaches a century of operational service in 2055.

Source: FlightGlobal.com