After a United Airlines Boeing 777-220 suffered an uncontained engine failure, Boeing requested the grounding of 128 aircraft around the world on February 21, 2021, pending a safety inspection. “While the NTSB investigation is ongoing, we recommended suspending operations of the 69 in-service and 59 in-storage 777s powered by Pratt & Whitney 4000-112 engines until the FAA identifies the appropriate inspection protocol,” announced the manufacturer following the incident. “We are working with these regulators as they take actions while these planes are on the ground and further inspections are conducted by Pratt & Whitney.”
The US Federal Aviation Administration (FAA) is set to publish an Emergency Airworthiness Directive (AD) requiring additional inspections of Boeing 777 airplanes equipped with the affected engines. “After consulting with my team of aviation safety experts about yesterday’s engine failure aboard a Boeing 777 airplane in Denver, I have directed them to issue an Emergency Airworthiness Directive that would require immediate or stepped-up inspections of Boeing 777 airplanes equipped with certain Pratt & Whitney PW4000 engines,” FAA administrator Steve Dickson announced on Twitter.
United Airlines, the company affected by the incident, withdrew 24 Boeing 777s from service. Korean Air announced its 6 Boeing 777s equipped with the same engine were grounded.
Two Japanese airlines, Japan Airlines (JAL) and All Nippon Airways (ANA), also grounded 13 and 19 aircraft, respectively, that are powered by the PW4000 engines. The Japanese transport ministry, which also ordered the grounding of these planes, said an engine of the same PW4000 family suffered problems on a domestic flight of a Boeing 777 on December 4, 2020, according to a Nikkei report. In response to the incident, more stringent inspections were required.
On February 20, 2021, a United Airlines Boeing 777-200, operating flight UAL328 from Denver, United States to Honolulu, Hawaii, US, suffered an uncontained engine failure, scattering engine parts over several neighborhoods around Denver.
Another P&W PW4000-powered aircraft, a Boeing 747-400F, also suffered an engine failure shortly after departure from Maastricht Aachen Airport (MST), in the Netherlands, as it departed for New York John F. Kennedy International Airport (JFK) on February 20, 2021. While the aircraft successfully diverted to Liege Airport (LGG), in Belgium, the Boeing 747-400F lost engine parts over a Dutch village, leaving two people injured.