Pratt & Whitney's new PW8000 geared turbofan is expected to make its first run in early 1999, with an entry into service date as early as 2002, says the company, which formally announced the three year development programme on 17 February (Flight International, 18-24 February).

The programme was kicked off by P&W president Karl Krapek at the company's annual briefing to analysts in New York, after the main board of United Technologies gave the project go ahead at the end of January. The PW8000 represents an ambitious move by P&W to retake a large slice of the narrowbody market from rival CFM International. The move is considered all the more daring because, for the first time in years, a major civil engine is being launched without a firm customer or application.

Bob Leduc, senior vice-president for programmes, says that a "25-35% market share inside seven to 10 years is realistic. It's no secret that our market share in this section of the business and below is in single digits - intolerable to us".

P&W is in "talks with everybody, but I'm not at liberty to talk about opportunities", he adds. The major target, however, is known to be the Airbus A320 family.

The PW8000 uses gearbox technology developed originally for the abandoned ADP (advanced ducted propulsor). Unlike the ADP, which was targeted at higher thrust levels, the PW8000 is aimed at a thrust range of 110k-155kN (25,000-35,000lb). The engine will also be based around the PW6000 core, under development for regional jet applications. Together, the PW6000 and PW8000 therefore represent P&W's combined assault on the 80- 180-seat market.

The 23,840kW (32,000shp) rated gearbox will drive a 1.93m-diameter fan, producing a bypass ratio of 11:1. The large diameter means that it will fit under the wing of the A320, but not that of the 737. "Boeing would have to look at new landing gear," says Leduc.

The engine will have 40% fewer stages than a comparable turbofan and 52% fewer compressor and turbine airfoils. P&W says that this will help achieve a 10% reduction in operating costs and up to a 30% cut in maintenance costs. Fuel consumption will also be up to 9% lower and the slower tip speed of the blades, combined with the high bypass ratio, is expected to cut noise levels by 30 cumulative decibels below Stage 3 requirements.

Key to the PW8000 is a Fiat developed gearbox, which P&W is confident will have an inspection interval of 30,000h between removals. The unit weighs 220kg and has a claimed efficiency of 99%.

The first complete engine will be assembled this year for a planned first run in early 1999. P&W's main partners in past programmes, Fiat, MTU and Volvo, have signed an agreement under which they have first right of refusal to participate in the programme.

P&W, meanwhile, has "no intention of selling our share in IAE [International Aero Engines]," says Leduc. "We are committed to that programme.

Source: Flight International