United Airlines Says PW4000 Inspection Work Progressing

UAL engine failure aftermath captured Feb. 22, 2021.
Credit: NTSB

United Airlines said Pratt & Whitney, the FAA and other stakeholders are making progress on getting Pratt PW4000-series engines back in service but declined to say when its affected 777s will return.

“There is progress, is the best way I would put it,” United COO Jon Roitman told Aviation Week MRO Americas attendees April 29. “It would be inappropriate for me to give a timeline, but it’s been productive.”

Global regulators grounded 130 Pratt-powered 777-200s, -200ERs and 300s following a PW4077 failure on United 777-200 on Feb. 20. Preliminary information released by investigators suggest that an undetected crack in one fan blade likely caused the part to fracture, triggering the failure. At least two similar incidents had occurred since 2018 suggesting that Pratt’s inspection protocols were not working. That prompted Boeing to recommend grounding the aircraft, followed by regulators mandating inspections of every fan blade in the fleet. 

Blades must be sent to Pratt for inspection, adding logistical complexity to an already challenging situation. Pratt did not immediately respond to a request for an update.

The issue forced operators to remove 59 affected aircraft from the schedules, including 24 at United. Another 70 Pratt-powered 777s were parked due to a lack of long-haul demand brought on by the COVID-19 pandemic.

The prolonged inspection process combined with a dire near-term outlook for long-haul demand could prompt carriers to retire affected aircraft instead of paying for initial and repetitive checks. Japan Airlines (JAL) in March accelerated its plans to remove nine PW4000-powered 777-200s and four 777-300s from its fleet. They were scheduled to be retired in 2022.

Executives at Pratt parent Raytheon did not address the PW4000 inspection issues on an April 27 earnings call. But CEO Greg Hayes noted that the JAL retirements will not necessarily remove the engines from service.

“Not a surprise that [it’s] 12 months before we had thought they were going to retire,” Hayes said. “But those engines will still end up in service someplace else, probably in a freighter configuration.”

United is adamant that its affected aircraft remain part of its future fleet plans.“We’re looking forward to getting the aircraft back as we move forward,” Roitman said. “We have really good collaboration with the FAA, NTSB, Pratt, and Boeing. We’re engaging pretty much daily.”

Sean Broderick

Senior Air Transport & Safety Editor Sean Broderick covers aviation safety, MRO, and the airline business from Aviation Week Network's Washington, D.C. office.