Rolls-Royce yesterday revealed new details of its Trent 900 as it reiterated its determination to win engine orders for 50% of the Boeing 747-500/600 and Airbus A3XX market.

R-R is confident that the Trent 900 will be lighter than its General Electric/Pratt & Whitney competitor because of the Trent's three-shaft layout: "Our weight advantage is going to be very, very difficult to erode," says chairman Sir Ralph Robins.



Trent 900 project director Charles Cuddington gave technical details of the new engine to a packed press conference at the show.

While retaining the fan diameter of the rent 800, the 900 will have 0.9 scaled Intermediate Pressure (IP) and High Pressure (HP) compressors and shortened combustor casing compared with the 800, together with new IP and HP turbines. This will give an 8.6:1 bypass ratio.

Investment cost for this new generation of the Trent is described as "moderate", a result of its being a derivative rather than a new design.

The commonality factor is seen by R-R as a major selling point.

"This will meet or exceed all Boeing's targets with ease," says Cuddington. "The three-shaft design means we can scale the compressors without affecting the fan."

First engine run will be in September 1998 and certification in December 1999.

"We forecast a market for 900 aircraft of this [747-500/600 and A3XX] type, 800 of them passenger and 100 freighters over a 25-year period".

R-R is also working with McDonnell Douglas on its proposed MD-XX, which will take a Trent 700-size powerplant.

The R-R commitment to go for a derivative approach in developing engines for the next generation superjumbo market chimes remarkably well with Boeing's own outlook.

In comparing its approach to that of rival Airbus Industrie, Boeing said yesterday it favours derivatives first - all new projects second.





Source: Flight Daily News