Guy Norris/LOSANGELES
GENERAL ELECTRIC is set to sanction a revised growth plan for the GE90 turbofan by the end of this month, by agreeing to develop an engine capable of being in service at thrust levels up to 445kN (100,000lb) by 1999. The engine will be capable of powering every version of the Boeing 777 now planned.
The new growth plan effectively leapfrogs the original scheme, which involved an intermediate development of a 423-436kN power plant followed later by a move, to a much more powerful version capable of between 467kN and 512kN.
The plan will see GE bypassing the staged growth plans of rivals Pratt & Whitney and Rolls-Royce, both of which are developing engine variants in the 423-436kN category for the 777-300.
"Initial approval could be granted by the end of the month," says GE90 marketing development manager Vince DiGiovanni. The 445kN engine would be derated for use on the 777-300, heavier versions of the -200 and possibly the -100X or ultra-long range -200 alternative. GE expects that the growth engine could be certified in 1998 and enter service in 1999. The additional thrust would be created through revised blade aerodynamics throughout the rotating parts of the engine, using technology derived from the recent CFM56-7. The fan would be identical to the current GE90 in size and make-up.
"We designed and built a 100,000lb thrust engine from the beginning. We made the (intermediate growth) steps six years ago," says DiGiovanni. Testing, on the first growth step engine, the GE90-92B rated at almost 410kN is virtually complete.
"It's on-line for certification in June," he says, the engine will power the first Boeing 777-200IGW (increased gross weight) aircraft scheduled for delivery to British Airways early in 1997.
Source: Flight International
