Max Kingsley-Jones/LONDON

ROLLS-ROYCE has signed an agreement with Boeing which will see it offer the Trent 900 to power the proposed 747-500/600X in direct competition with the General Electric/Pratt & Whitney joint venture.

The planned Trent 900, described as a "low-risk derivative" of the Trent 800, could also have applications for the Airbus A3XX. R-R says that certification of the new engine will be completed within 33 months of go-ahead, to enable service entry in 2000. It is optimistic that a go-ahead will be received around the turn of the year.

The engine will combine a scaled-down version of the Trent 800 core and use a similar 2.8m-diameter fan, as well as borrowing a range of other accessories, dressings and strucutural components. A slimline, lower- weight nacelle will also be developed to enable the engine to be installed under the wing of the new 747.

The smaller core will increase the bypass ratio from around 6.5 on the Trent 800, to 8.5. The engine will be offered at thrust levels from 345kN (78,000lb) to 356kN on the 747 derivatives, while the Airbus proposals envisage a slightly lower 310-335kN requirement.

"The Trent 900 will offer significant weight and performance advantages over the competition," claims David Wicks, sales director for R-R commercial engines. He says that R-R "-will maintain the weight advantage" from the Boeing 777's Trent 800, offering a 2,270kg saving per aircraft over the GE/P&W offering. "Fuel consumption will be about 1.5% better than the competition, which equates to about 280km more range," he says.

Wicks adds that R-R expects to guarantee noise levels "no higher than for the current 747-400" while the scaled-down Trent 800 combustor will "-satisfy all future requirements" likely to emerge.

A Trent 900 project team has been formed headed by project director Charles Cuddington.

Source: Flight International