WASHINGTON (Reuters) – A United Airlines plane with a Pratt & Whitney engine that went out on Saturday had flown less than half of the flights allowed between fan blade inspections by US regulators, two knowledgeable sources said .
The Boeing Co 777 aircraft had flown nearly 3,000 cycles, equivalent to one take-off and landing, which is comparable to the checks every 6,500 cycles imposed after a separate United engine incident in 2018, the 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 ramp up checks to every 1,000 cycles, in a bulletin spotted by Reuters. It did not immediately respond to a request for comment.
On Tuesday, the US Federal Aviation Administration said it ordered immediate inspections of 777 aircraft with PW4000 engines before they could return to flight beyond Pratt.
The engines are used on 128 older versions of the aircraft, accounting for 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 operated them recently.
Japan and South Korea also grounded the planes for checking the fan blades.
On Monday, the FAA acknowledged that after a Japan Airlines (JAL) PW4000 engine incident in December, it had considered stepping up blade inspections using thermal acoustic imaging to find signs of metal fatigue.
A risk assessment meeting was held last week to discuss the issue before United’s engine shut down on Saturday, one of the sources said, confirming an earlier report from CNN. Prior to the incident with United, no decision was imminent, the source added.
A spokeswoman for Pratt, owned by Raytheon Technologies, said on Wednesday that fan blades should be shipped to the repair station in East Hartford, Connecticut, for final inspections, including those from Japan and South Korea.
Each motor has 22 blades that must be individually removed and each will take eight hours to inspect, FAA administrator Steve Dickson told Bloomberg TV on Wednesday.
That’s the equivalent of 352 hours of work per plane, as every 777 has two engines. Boeing said 69 of the planes were on active duty prior to Saturday’s incident, while 59 planes were grounded during the pandemic due to low demand.
Pratt did not respond to questions about how many engines he could inspect per month. United did not say how long it expects the inspections to take, while JAL and ANA Holdings said the timing was unclear.
(This story corrects to remove unnecessary word ‘and’ in paragraph 11)
Reporting by David Shepardson in Washington; additional reporting by Tim Kelly in Tokyo, written by Jamie Freed. Editing by Gerry Doyle