WASHINGTON (Reuters) – A United Airlines plane with a Pratt & Whitney engine that crashed on Saturday flew less than half of the flights allowed by US regulators between inspections of fan blades, two sources with knowledge of the matter said.
The Boeing Co 777 flew nearly 3,000 cycles, equivalent to a takeoff and landing, which compares to checks on every 6,500 cycles imposed after a separate United engine incident in 2018, sources said.
They sought anonymity because they were not allowed to speak in public. United declined to comment.
Pratt, the maker of the PW4000 engines, on Monday recommended that airlines step up checks every 1,000 cycles, according to a Reuters report. 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 aircraft before they could return to flight, going further than Pratt.
The engines are used on 128 older versions of the aircraft, accounting 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 have recently operated them.
Japan and South Korea also grounded planes to check the fan blade.
On Monday, the FAA acknowledged that, following a Japan Airlines (JAL) PW4000 engine incident in December, it considered stepping up inspections with blades that use acoustic thermal imaging to find signs of metal fatigue.
A risk assessment meeting was held last week to discuss the issue before United’s engine gave way on Saturday, one source said, confirming a previous CNN report. No decision was imminent before the United incident, the source added.
A spokeswoman for Pratt, owned by Raytheon Technologies, said Wednesday that fan blades should be transported to the 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.
This is the equivalent of 352 hours of work on the plane, as each 777 has two engines. Boeing said 69 of the planes were in active service before Saturday’s incident, while 59 were grounded amid reduced demand during the pandemic.
Pratt did not answer questions about how many engines he could inspect per month. United did not comment on how long the inspections are expected to last, while JAL and ANA Holdings said the timetable is unclear.
(This story is corrected to remove the foreign words “and” in paragraph 11)
David Shepardson’s report to Washington; additional report by Tim Kelly in Tokyo, written by Jamie Freed. Editing by Gerry Doyle