GUY NORRIS / LOS ANGELES
Improvements aimed at enhancing range and payload of Airbus A340-500/600
Rolls-Royce is poised to launch a set of proposed Trent 500 engine enhancement performance (EP) packages, the first of which could be available for the Airbus A340-500/600 in early 2003.
The engine maker says the enhancements are aimed at "a pure sfc [specific fuel consumption] improvement" leading to increased payload and range for family variants in the ongoing contest with the Boeing 777-200LR/300ER. Studies of the EP follow Airbus' 1999 requests to suppliers and partners for data on potentially enhancing long range performance, and are based in part on technology in development for the Trent 900 destined for the A380. "We are working with Airbus and looking at how much makes sense, and how much could be retrofittable," says Trent 500/900 director Ian Kinnear who stresses: "It is not an attempt to recover performance. It's about enhancing performance."
R-R maintains that the newest configuration engines being delivered as the first production standard shipset to Toulouse this month "will meet specification". Airbus has acknowledged that the initial run of production aircraft up to number 24 will be overweight, and is instituting a programme based largely on structural weight reductions.
Kinnear admits that flight test engine sfc is "up to 2% adrift" but is "exactly consistent with where we thought they'd be at this stage". Recently delivered flight compliance engines are "already demonstrating around 1% better than the early engines, and the more recent ones are a bit better than that".
The initial focus of the proposed EP is an upgraded low pressure turbine (LPT). Kinnear says sfc improvements could give the aircraft up to a 740km (400nm) advantage over the 777-300ER. The LPT change could "make sense for engines built for delivery in 2003", he adds. Extensive use of three-dimensional aerodynamic design is planned for the EP, including the shaping of blades, stators and end walls. "We are improving the working efficiency of the turbine and reducing secondary losses near the annulus wall," says Kinnear.
Source: Flight International
