Ten Rolls-Royce Trent XWB engines–serial numbers (S/Ns) 20990, 20001 through 20006, 20009 and 21000–are being used in the test program.

•By last month, some 43 hours’ testing had been accumulated during 14 of 16 scheduled flights with initial flight-test unit S/N 20990, which will subsequently be available to provide spare capacity. Rolls-Royce says the powerplant is its most highly instrumented flight-test engine ever.

•Previously used for performance-envelope expansion, compressor functional operations, and operability testing and medium-weight bird-ingestion trials using strain-gauged fan blades, Trent XWB S/N 20001 has this year been used for “successful” cold-start and icing tests in Manitoba, Canada.

•After low-pressure turbine testing and aircraft-interface systems-integration trials on Rolls-Royce’s Test Bed 58 at Derby in the UK last year, Trent XWB1C S/N 20002 was scheduled for thermal and emissions tests, integration of buyer-furnished equipment and water-ingestion trials. It was used in March this year for “large flocking bird” ingestion tests, when it met certification requirements, according to the manufacturer, which said that “over time” the hollow titanium fan blades may be replaced by carbon fiber items.

•In late May, Rolls-Royce had almost completed cyclic-maturity tests involving a 1,000-hour maintenance-interval simulation trial with Trent XWB 1A/1 S/N 20003.

•Endurance testing with involving “lots of hours” at high speed and high thrust has been conducted on S/N 20004.

•Trent XWB 20005 has been used for flutter and cross-wind tests, as well as thermal-survey work, which confirmed cooler-than-predicted disc-cavity temperatures. A U.S. test program with this unit has involved fan strain-gauging and noise trials. It has recently completed initial thrust-reverser unit cycling tests.

• Rolls-Royce reports “positive” results following completion of altitude performance and operability testing with S/N 20006. The powerplant had previously been used to validate sea-level performance, low-, intermediate- and high-pressure bearing loads, variable-frequency generators, and oil-system optimization.

•Thermal and strain-gauge testing of the intermediate pressure turbine has been performed on Trent XWB S/N 20007.

•Trent XWB S/N 20009 has been used for engine high-pressure system telemetry.

In addition, three other Trent XWBs are being manufactured to provide spare capacity and a further unit will be produced for Rolls-Royce in-house training in its Derby headquarters.