BOEING BEGAN a 1,000-flight service-ready testing programme of the Pratt & Whitney PW4084-powered 777 on 29 December 1994, almost two months later than hoped. It says that cyclic testing is going better than expected, however.
Approval for extended-range twin-engine operations (ETOPS) with the 777 when the twinjet enters service with launch customer United Airlines in June is dependent on successful completion of the 1,000-flight-test programme now under way.
Boeing had hoped to begin service-ready testing soon after the first flight of the aircraft, the fourth 777, on 28 October. The manufacturer says that it is still on track for certification of the 777 in mid-April and delivery of the first aircraft to United in mid-May, but notes that it has until the aircraft enters service in mid-June to complete service-ready testing.
The manufacturer says that cycles are being accumulated faster than expected, with up to 12 flights a day being completed. Plans call for a high-time PW4084 to be installed after 500 cycles have been logged and, towards the end of service-ready testing, almost 100 flights will be operated on representative city-pairs by flight and ground crews provided by United.
Boeing has accumulated more than 540 flights and 1,430h on five P&W-powered 777s. Delayed certification of the General Electric GE90 is now expected in mid-January and will be followed by the first flight of a GE90-powered 777, destined for British Airways.
Source: Flight International
