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Rolls-Royce's Trent 500 turbofan for the Airbus Industrie A340-500/600 was expected to begin runs at the company's test site at Derby, UK, as Flight International went to press. The run marks the start of a test and certification programme involving seven test engines, which is due to be completed in December 2000.

To ensure a smooth introduction into service and high reliability, Rolls-Royce plans to run 2,000 simulated extended range twin engined operations (ETOPS) cycles. The tests are still being conducted, despite the fact that the A340 is a four-engined application, and therefore does not require ETOPS qualification.

"We are doing it because the Trent 800 has been doing really well in terms of disruptive reliability related delays," says Trent 500 head of marketing Robert Nuttall.

The engine has a 2.46m (97in) diameter wide-chord fan and an eight-stage intermediate pressure compressor with three-dimensional (3D) aerodynamic design. It also incorporates a six-stage high-pressure (HP) compressor with 3D design, an annular tiled combustor and a single-stage HP turbine. The Trent 500 features a five-stage low-pressure turbine section.

The fan combines aerodynamic refinements of both the Trent 700 and 800 designs, but does not feature the Trent 8104's swept blade design. The compressor system is a 20% scaled version of the Trent 892, while the combustor is scaled for the airflow of the Trent 500 from the 800 version. The turbines are also scaled from the Trent 800, generating an "advantage in terms of aerodynamic loading", says Nuttall, which increases overall efficiency and "gives us about a 1.5% improvement in specific fuel consumption", he adds.

The engine is due to be certificated at a thrust rating of 60,000lb (267kN), but will enter service at 56,000lb. "Most operators will de-rate from that level," says Nuttall, to increase temperature margin and life on-wing. The powerplant will be flight tested on the A340-300 development aircraft next year, and will enter service on the A340-600 in March 2002.

Source: Flight International