PRATT & Whitney's 400kN (90,000lb)-thrust PW4090 engine has entered a five-month flight-test programme on the first Boeing 777 aircraft, WA001.
The engine will power 777-200IGW versions on order from Korean Air and United Airlines, the first of which will enter service in March 1997. The engine is an uprated version of the original PW4084 which entered service on the Boeing twinjet in June 1995. The higher thrust of the PW4090 has been achieved through improved compressor aerodynamics and cooling changes in the high- and low-pressure turbines.
The tests started on 3 August, and initial trials in the programme, which is expected to amass around 150h is concentrating on basic engine-operating characteristics.
Tests scheduled to run into the week of 11 August will also look at "engine-intermix" performance, in which the standard PW4084, on one wing, and the test PW4090 on the other wing, are derated to 343kN thrust.
After months of delay the General Electric GE90 and Rolls-Royce Trent extended-range twinjet-operations test programmes were completed on the Boeing 777 around the end of July.
Source: Flight International
