WASHINGTON (Reuters) – A United Airlines plane with a Pratt & Whitney engine that crashed Saturday had flown less than half of the flights allowed by U.S. regulators amid inspections of fan blades, two sources with knowledge of the question.
The Boeing Co 777 aircraft had flown about 3,000 cycles, equivalent to a takeoff and landing, which compares to controls every 6,500 cycles required after a separate United engine incident in 2018, sources said.
They sought anonymity as they were not allowed to speak publicly. United declined to comment.
Pratt, the maker of the PW4000 engines, on Monday advised airlines to intensify checks every 1,000 cycles, in a bulletin seen by Reuters. He did not immediately respond to a request for comment.
On Tuesday, the U.S. Federal Aviation Administration said it was ordering immediate inspections of 777 PW4000-powered aircraft before they could return to flight, going beyond Pratt.
The engines are used in 128 previous versions of the aircraft, which account for less than 10% of the more than 1,600,777 delivered and only a handful of airlines in the United States, South Korea and Japan operated them recently.
Japan and South Korea have also grounded planes to check fan blades.
On Monday, the FAA acknowledged that after a Japan Airlines (JAL) PW4000 engine incident in December, it had been considering stepping up inspections of blades using acoustic thermal imaging to find signs of metal fatigue.
A risk assessment meeting was held last week to discuss the issue before the United engine failed on Saturday, one source said, confirming a previous CNN report. No source had been imminent before the United incident, the source added.
A spokeswoman for Pratt, owned by Raytheon Technologies, said Wednesday that fan blades should be sent to its repair station in East Hartford, Connecticut, for final 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.
This equates to 352 hours of work per aircraft, as each 777 has two engines. Boeing said 69 of the planes were in active service before Saturday’s incident, while 59 had been landed amid low demand during the pandemic.
Pratt did not answer questions about how many engines he could inspect per month. United have not commented on how long it will take for inspections to take place, while JAL and ANA Holdings said the timing was unclear.
(This story is corrected to remove the odd words ‘and’ in paragraph 11)
Report by David Shepardson in Washington; additional report by Tim Kelly in Tokyo written by Jamie Freed. Edited by Gerry Doyle