Bleedless 787 engine has successful first run, kicking off 18-month certification effort
Rolls-Royce began test runs of the Trent 1000 for Boeing’s 787 on 14 February, marking the start of an intensive 18-month development and certification effort as well as the first run of a more-electric commercial turbofan.
The engine, which is the launch power plant on the 787 and therefore the first to run, is scheduled to be certificated at thrust levels up to 75,000lb (338kN) in July 2007. This is 5,000lb higher than originally stated, and takes into account the expected thrust growth associated with Boeing’s decisions in 2005 to increase the gross weight of the stretched -9 as well as offer the “double-stretch” 787-10.
“We will support Boeing in whatever they choose to do with the 787,” says Dominic Horwood, Rolls-Royce director of Boeing programmes, who adds the Trent 1000 is “not only the first engine to be started electrically, but is the first major piece of the 787 to run”.
The engine “started beautifully” first time using dual-use Hamilton Sundstrand starter/generators that in flight connect to the intermediate power (IP) compressor, rather than the more conventional high pressure (HP) spool, to provide electrical power. This allows the engine to generate sufficient power from the generators even at lower thrust settings at flight phases such as descent, and will reduce block fuel consumption on shorter-range flights by up to 6% compared to previous Trent engines, says Horwood.
The first engine is one of seven initial ground test powerplants in the certification programme, and will form the focus for low-pressure system evaluation. Engine number two, due to enter the programme before the end of March, will be used specifically for IP system work, while the third engine due by the end of April, will be the focus for HP system work. A fourth engine will be transported to the Arnold Engineering Development Center, Tullahoma, Tennessee, in mid-year for altitude and icing tests. Engines five and six will be dedicated to endurance and type testing, while the seventh will undergo fan blade-off tests by the end of 2006.
GUY NORRIS / LOS ANGELES