Guy Norris/LOS ANGELES
The swept, 3.2m (10.5ft) diameter fan-blade of General Electric's growth GE90-115B engine for the Boeing 777-200LR/ 300ER longer range models are being prepared for crucial birdstrike tests at Snecma in France as GE nears the end of the design release stage which began last August.
Conversion of GE's 747-100 flying testbed to accept the engine is to begin in December. GE plans to fly the GE90-115B on the testbed for the first time in February 2002, with first flight on the initial 777-300ER due in December next year.
Initial bird tests on the larger, swept-blade design for the new engine are complete for 1.1kg (2.5lb) and 1.8kg birds which were fired at the 50% span position, after which the blades were "completely serviceable", says Dick Ostrom, manager of GE90 integration. The tests start over the next two months involving birds up to 3.2kg, and will be completed in July.
GE is also developing a larger version of its advanced twin annular pre-swirl (TAPS) combustor design for tests on a GE90 in 2002, for possible introduction on later generations. The new version will be a dual annular combustor derivative of the TAPS, combining the advanced co-annular swirling technology of the latter with the former's radial staging architecture.
The combination would "probably make the GE90 capable of emissions levels more than 50% below the ICAO/CAEP 2 nitrous oxide [NOx] limits", says GE advanced engineering general manager, Mike Benzakein.
"We plan to run the first component tests this year, and we hope to run an engine test on the GE90 in 2002, but we have made no decision on introducing it yet. It depends on the market," he adds. The current GE90 is already 25% to 30% below the ICAO mininums, but Benzakein says the TAPS test is part of GE's work to "get us positioned" for more stringent environmental regulations.
Benzakein says the new combustor could be introduced quite soon, "but in reality I don't see it getting into the product line before 2006-2007". The ground work for the TAPS concept is at an advanced stage through CFM International's Tech56 programme which is developing new technology to keep the CFM56 competitive.
Source: Flight International
