WASHINGTON (Reuters) – A United Airlines plane with a Pratt & Whitney engine that failed on Saturday had made less than half of the flights allowed by US regulators between fan blade inspections, two sources with knowledge of the matter said.
The Boeing Co 777 jet had flown nearly 3,000 cycles, equivalent to one take-off and landing, compared to the 6,500-cycle checks required after a United engine incident in 2018, sources said.
They sought anonymity because they were not authorized to speak in public. United declined to comment.
Pratt, the maker of the PW4000 engines, advised airlines on Monday to step up checks every 1,000 cycles, in a bulletin seen by Reuters. He did not immediately respond to a request for comment.
On Tuesday, the US Federal Aviation Administration said it was ordering immediate inspections of 777 PW4000-powered aircraft before they could return to flight, going further than Pratt.
The engines are used in 128 previous versions of the aircraft, representing less than 10% of the more than 1,600 777s delivered and only a handful of airlines in the United States, South Korea and Japan were operating them recently.
Japan and South Korea have also grounded the planes to check the fan blades.
On Monday, the FAA acknowledged that after an incident with the Japan Airlines (JAL) PW4000 engine in December, it had been considering intensifying inspections of blades that use thermoacoustic imaging to find signs of metal fatigue.
A risk assessment meeting was held last week to discuss the issue before United’s engine failed on Saturday, one of the sources said, confirming an earlier CNN report. No decision had been imminent prior to the United incident, the source added.
A spokeswoman for Pratt, owned by Raytheon Technologies, said Wednesday that the fan blades should be sent to its repair station in East Hartford, Connecticut, for the latest inspections, including those in Japan and South Korea.
Each engine has 22 blades that must be removed individually and each will take eight hours to inspect, FAA Administrator Steve Dickson told Bloomberg TV on Wednesday.
That equates to 352 hours of work per plane, since every 777 has two engines. Boeing said 69 of the jets were on active duty before Saturday’s incident, while 59 had been grounded amid low demand during the pandemic.
Pratt did not respond to questions about how many engines it could inspect per month. United has not commented on how long it expects the inspections to take, while JAL and ANA Holdings said the timing was unclear.
(This story corrects to remove the strange word ‘y’ in paragraph 11)
David Shepardson’s report in Washington; Additional reporting on Tim Kelly in Tokyo written by Jamie Freed. Edited by Gerry Doyle