Kieran Daly/DERBY
ROLLS-ROYCE WILL begin flight testing of the Trent 890 for the Boeing 777 on the airframer's 747 testbed in late March.
The company had hoped to avoid the 747 test phase, but Boeing insisted, following unexpected events with the rival Pratt & Whitney and General Electric engines at the same stage.
Trent 800 chief engineer Mike Terrett says that the first flight of the Trent 890 on the 747 will take place in the week beginning 20 March. The engine involved will be the second production unit. In the same week, the 777 itself will be fitted with a Trent for the first time.
The plan is to complete "15-20h" airborne time on the 747. First flight of the Trent-powered 777 is scheduled for the last weekend of May, on a Boeing "in-house" aircraft, using the second production engine. That will be followed by first flight of a Trent-powered 777 for Cathay Pacific in August.
Terrett says: "We were not going to do the 747 tests, but experience last year made Boeing, driven by the pilot community, want to do it. It is also an emotional thing in getting the whole Boeing community involved in it and that is an intangible thing that is hard to put a value on."
Citing the double engine-surge suffered by one of the P&W PW4084 engines on an early 777 flight, Terrett explains: "We will just do some take-offs and we will do some re-lighting. It will be a maximum of three flights."
R-R is stressing the significance of using production engines in the aircraft-development programme as a contributor towards Boeing's "service-ready" concept.
Terrett says that, for example, a production engine will be used for the 3,000h out-of-balance ground-running test, which is a key feature of Boeing's programme.
He says: "On the 890, I think it is unique that we will just take a production engine complete and use that. We have also put in place a very strict (design) change process. We have effectively brought entry-into-service forward, so the engine is 99.99% the same part numbers as in production."
Source: Flight International
