Pratt & Whitney has resumed production of its PW1000G family of geared-turbofan (GTF) engines after introducing a revised configuration for the knife-edge seal on each engine’s high-pressure compressor aft hub and obtaining FAA, EASA, and Airbus approval.
A new design for the knife-edge seal that P&W introduced into new-production GTF engines in December, along with 16 other engineering changes to its PW1000G engines, “did not play out as expected,” Greg Hayes, CEO and chairman of P&W’s parent United Technologies said Wednesday. In late January and early February the issue affected four new PW1100G-JM engines on A320neo-family aircraft, according to a February 12 P&W media statement, causing operators to experience rejected takeoffs and in-flight shutdowns. The FAA then issued an emergency airworthiness directive affecting 43 PW1100G-JM engines already installed on wing and another 55 delivered to Airbus.
However, Hayes told delegates at the Barclays Industrial Select conference in Miami Beach on Wednesday that the engine maker resumed GTF production last week and that new PW1100G-JM engines with the revised knife-edge seal configuration will be delivered to Airbus starting in early March. After installation on A320neo-family jets, those engines will go to the customers for the aircraft beginning in early April.
Hayes revealed that for its PW1100G-JM knife-edge seal fix, P&W “went back to the earlier design” of the seal. In a media statement on Wednesday announcing the solution to the issue, Pratt & Whitney essentially confirmed this by saying that “the solution is based on a design with which the company has significant experience.”
Despite the temporary halt in GTF production that the knife-edge seal problem produced, Hayes told delegates at the conference that “we still feel good about our delivery commitments to Airbus and to customers through the rest of the year.” Hayes said in January that, P&W having delivered 374 GTF engines in 2017, a total squarely in the middle of its 350- to 400-GTF production target for the year, the engine maker plans to double GTF production this year to approximately 750 to 760 engines.
PW1100G-JM engines have now accumulated approximately 300,000 flight hours in service and, together, all other PW1000G modes have accumulated approximately 200,000 flight hours, according to Hayes, who estimated the in-service GTF fleet will reach 1 million hours of accumulated flight time “later this year.” He added that “until we get to 1 million hours, it’s still a new engine.” However, “once we get to 1 million hours, we will have cleared most of the teething issues.”
Hayes also revealed that each doubling of the GTF engine production rate results in a 13 percent production-cost reduction per engine, so by doubling the rate in 2018, the company should achieve a per-engine production cost approximately 13 percent lower than in 2017.