GE90-Powered 777 Resumes Certification Flight Test Program
EVENDALE, Ohio - A GE90-powered Boeing 777 aircraft successfully resumed certification flight testing following formal approval by the Federal Aviation Administration (FAA).
FAA officials were aboard the aircraft for yesterday's two scheduled flights at Boeing Field in Seattle, Washington. The flights, totaling approximately five hours, marked the resumption of FAA testing required for certification of the GE90-powered 777.
The test aircraft first returned to flight on Sunday, July 16, and has flown regularly since then, accumulating approximately 12 flight hours in the past five days. Daily flights are ongoing.
The GE90/777 aircraft resumed flights with minor modifications to the engine's aluminum platform spacers (situated between the fan blades) and the electronic control system. Both modifications were successfully demonstrated and were approved by the FAA.
GE90/777 flights were halted on May 30 after a bird-strike test conducted on the test stand using a full set of GE90 blades, revealed a greater-than-expected imbalance. After modifying the platform spacers, which ensure a smooth aerodynamic flow between the blades, GE successfully repeated the test on July 7. This time, the results were well within FAA requirements.
The software modification, involving a minor adjustment of the stator schedule in the GE90 control system, resulted from a May 4 engine surge during flight testing. On July 18, the GE90/777 test aircraft successfully duplicated the takeoff sequence without experiencing a surge.
Since the flight test program began in February, the GE90 has accumulated more than 280 flight hours powering 777 flight test aircraft. Also, the GE90 has accumulated 228 hours on GE Aircraft Engines' (GEAE) 747 flying testbed aircraft.
In the most rigorous engine testing program in GEAE history, the GE90 has accumulated 14,300 engine cycles during testing. The GE90 was certified earlier this year at 84,700 pounds of thrust, but has operated for more than 65 hours above 100,000 pounds of thrust during the development program.
The GE90 has been developed to meet the growing thrust requirements of the 777 well into the future. GEAE and Boeing are working toward the scheduled first delivery of the GE90-powered 777 aircraft to British Airways in late September.