United Airlines has confirmed when its Boeing 777 aircraft powered by Pratt & Whitney PW4000 engines will be back in service.
United Airlines’ chief commercial officer (CCO), Andrew Nocella, told the media on May 17, 2022, that the carrier aims to return its grounded Boeing 777 jets to operation the following week after receiving all necessary permissions from the Federal Aviation Administration.
“The FAA issued the final paperwork on our Pratt Whitney powered 777s,” the COO confirmed. “We expect to start flying the aircraft ad hoc probably within the next week.”
In late February 2021, United Airlines temporarily removed 24 Boeing 777-200 airliners with Pratt & Whitney PW4000 engines from the operation. After the incident with flight UAL328 on February 20, 2021, the decision was made.
The United Boeing 777-200 airplane, registered N772UA, was traveling from Denver, Colorado, to Honolulu, Hawaii, when it experienced an uncontained engine failure, distributing engine pieces throughout various Denver neighborhoods.
Following the incident, Boeing requested the grounding of 128 aircraft all over the world, awaiting a safety inspection.
The FAA responded by issuing an emergency airworthiness directive (AD) mandating all owners and operators of Pratt & Whitney PW4000-112 engines that power Boeing 777s to conduct a thermal acoustic imaging inspection before flying again.
United had expected to resume passenger service on the impacted 777s by the summer of 2021. However, the FAA issued three airworthiness directives on March 11, 2022, requiring more corrective actions on PW4000 engines.
Repetitive ultrasonic and thermal acoustic imaging examinations for cracks in fan blades, as well as structural fortification of the engine inlet to withstand fan blade failures.
Prior to the event, United Airlines, based in Chicago, was the only carrier in the United States using the Boeing 777-200 version.
After Japan’s Ministry of Land, Infrastructure, Transport, and Tourism lifted the suspension, Japan Airlines (JAL) and All Nippon Airways (ANA) both returned their PW4000-powered Boeing 777s in March 2022.