PW6000 Mock-up at Asian Aerospace

Asian Aerospace 2000 -- On show here for the first time is a full-scale mock-up of the PW6000 engine, which Pratt & Whitney announced at the 1998 show. The 18-20,000-pound thrust engine is due to make its first flight this summer aboard the Pratt & Whitney Canada Boeing 720 flying test-bed. First deliveries aboard the Airbus A318 are due in the fourth quarter of 2002.

Extensive rig tests are showing encouraging results with the PW6000's high-pressure compressor, a five-stage design which features higher blade and stage loadings than any previous commercial engine. The compressor has already been running for over a year.

When P&W announced the PW6000, the company also said it would develop a larger engine using the same core and a low-noise, high-efficiency fan, driven by a reduction gear. One of the company's gear test rigs is on show here.

Pratt & Whitney has highlighted two innovations in the design of the 3:1 gear system. The lubrication system is designed to use the minimum amount of oil and to remove it as rapidly as possible from the engine. This reduces the build-up of heat due to oil churning and eliminates the need for a large oil cooler.

Another important feature is a flexible mounting system that carries the star gears which connect the input to the output gears. The mounting system keeps the gears aligned despite any flex loads on the engine, extending their life. P&W is aiming for a 30,000 hour time between overhauls.

Originally intended to power 180-200-seat twin-engine aircraft, the geared engine is now seen as a candidate to power a future version of the A340-500/600. Compared with the current Rolls-Royce Trent 500, the geared engine could be 10% more efficient (with a corresponding range increase) and would achieve noise levels well below Stage 4 rules.

By Bill Sweetman