THE BOEING 777 Pratt & Whitney PW4084 was granted US Federal Aviation Administration approval on 30 May to fly 180min extended-range twin-engine operations (ETOPS) at service entry.
The "ETOPS-out-of-the-box" initiative was a key target for Boeing from the start, and was achieved just a week before the start of commercial services between London and Washington DC with United Airlines on 7 June. The European Joint Aviation Authorities, however, is now set to grant only 120min ETOPS clearance.
Boeing Commercial Airplane group president Ron Woodard says: "FAA approval for 180-minute ETOPS at service entry is a final milestone for the Boeing 777/Pratt & Whitney flight-test programme. This approval signifies that the 777 not only has completed the 1,000-cycle validation programme, but that it has finished one of the most thorough laboratory, ground and flight-testing efforts in aviation history."
The 1,000-cycle validation programme included 90 cycles, flown over 400h, which were operated in conjunction with United Airlines ground and flight personnel. During flight testing, the 777 underwent eight 180min single-engine diversions for a total of 24h. By the end of May, the 777 flight-test programme had accounted for more than 1,950 flights and over 3,670 flight hours.
The first Rolls-Royce Trent 800 777 had its maiden flight on 26 May. The 777, in Cathay Pacific colours, flew for 5h 15min and reached 33,000ft (10,000m) and 365kt (675km/h). Slam-engine accelerations and decelerations, and engine-relight tests were included. The Trent was approved in January and is cleared for 400kN (90,000lb) thrust. Commercial operations start in January 1996 with Thai Airways International.
Source: Flight International
