US turboshaft engine makers are awaiting the first US Army contract awards that will launch an eight-year competition to replace the 47-year-old Honeywell T55 engine family.

The army's Future Affordable Turbine Engine (Fate) aims to replace the T55 with a new engine in the 6,000-7,000shp (4,470-5,215kW) range to power either a growth version of the CH-47 Chinook or a follow-on rotorcraft. The goals for Fate include reducing specific fuel consumption by 35%, slashing production and maintenance costs each by 40-45% and improving shaft horsepower to weight ratio by 90%.

The Army Aviation Technology Directorate is expected to soon award contracts to develop the technologies for an improved turbine. A second round of contracts will focus on developing a next-generation compressor. Those activities will be followed by the four-year Fate technology demonstrator programme starting in fiscal year 2012. An all-new production engine would be available by the end of the decade.

General Electric, Pratt & Whitney and Honeywell confirm they are participating in the Fate programme. Rolls-Royce, maker of the T406 and the AE1107C, has declined to comment.

Fate is proceeding even as the army continues to debate whether to launch an all-new Joint Heavy Lift rotorcraft, or perhaps invest in a growth version of the T55-powered Boeing CH-47 Chinook.

Boeing confirms a decision to launch a growth Chinook has slipped from the FY2010 budgeting cycle to FY2012. But the company has narrowed its options for the larger design.

The baseline CH-47's 25,400kg (56,000lb) airframe would increase to 31,700kg, and the fuselage would widen by 0.3m (1ft) to accommodate an up-armoured Humvee, says Jack Dougherty, director of CH-47 programmes.

Engine suppliers continue to hedge their bets by supporting both Fate and the growth Chinook, which would require a power upgrade from the 4,800shp T55-GA-714. Honeywell has prepared a new kit design for a 6,500shp T55-GA-715.

"If you look at the history of the T55 and the Chinook, about every three to five years the aircraft has grown and therefore the power has grown," says Ron Kotwal, Honeywell's marketing and product manager for propulsion products. "When we are talking about the T55 kit upgrade it does not involve any technology development."

Honeywell, however, is likely to face competition even if the army selects the growth Chinook. "There are some near-term studies that are going on right now on more near-term products could be used in some type of growth version of a Chinook helicopter," says Jerry Wheeler, a Pratt & Whitney product manager. "We are participating with Boeing in studies of a growth application of the Chinook."

Source: Flight International