Pratt & Whitney aims in August to flight test on its ex-Air China Boeing 747SP testbed the first PW4000 modified to cure the engine's long-running compressor surge problems.
The high-pressure compressor ring case modification kit is based on the design used in the PW4000 version developed for the 777, and has already been validated in flight tests on the SP "with very encouraging results", says Bob Leduc, P&W executive vice-president for large commercial engines.
"We bought this 747SP to test engines that had failed in service as part of our root cause investigation," he adds.
Certification of the baseline modification kit is expected around November. Retrofitting the 2,400 engines affected by the upgrade begin later in 2003 and is expected to be completed in the first quarter of 2007.
Source: Flight International
