Airlines around the world have begun grounding their Boeing B777 fleets operated by certain Pratt & Whitney PW4000 engines following an uncontained engine failure on a United flight on 20th February,2021.
Debris from the impacted engine fell in locations across Denver, creating an extremely high injury risk.
Boeing recommends grounding
Following the events of United Airlines flight UA328, Boeing has recommended that airlines ground their 777-200 and 777-300 fleets equipped with the Pratt & Whitney 4000-112 engines. This decision will impact 69 aircraft that are currently in service and another 59 that are in storage. The decision comes as the NTSB investigates the Denver incident. The FAA has issued an Emergency Airworthiness Directive to inspect all 777s with the same engines.
“Boeing is actively monitoring recent events related to United Airlines Flight 328. 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.”said Boeing in a statement.
However, even before Boeing’s recommendation to ground the B777 series, airlines and regulators began to ground the aircrafts. United grounded its fleet of 24 affected 777s following the incident and Japan’s aviation regulator ordered All Nippon Airways and Japan Airlines to do the same. South Korea remains the only country yet to ground its affected B777 fleet.
Boeing supports the decision yesterday by the Japan Civil Aviation Bureau, and the FAA’s action today to suspend operations of 777 aircraft powered by Pratt & Whitney 4000-112 engines. 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. Updates will be provided as more information becomes available.”added Boeing.
“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 order an Emergency Airworthiness Directive that would require immediate or stepped up inspections of Boeing 777 airplanes equipped with certain Pratt & Whitnet P4000 engines. This will likely mean that some airplanes will be removed from service. We reviewed all available safety data following yesterday’s incident. Based on the initial information, we concluded that the inspection interval should be stepped up for the hollow fan blades that are unique to this model of engine, used solely on 777 airplanes. The FAA is working closely with other civil aviation authorities to make this information available to affected operators in their jurisdictions. The FAA’s aviation safety experts are meeting into the evening with Pratt & Whitney and Boeing to finalize the details of the Airworthiness Directive and any accompanying service bulletins to ensure that the appropriate airplanes are included in the order. Exact details of the inspection will be specified in the emergency order.”read a statement by administrator Steve Dickson released by FAA.
What happened on United Airways flight 328?
The sudden groundings came after United flight 328 from Denver to Honolulu suffered an engine failure over the city. The failure caused parts of the engine, large and small, to fall over areas of Denver, endangering residents on the ground. Dozens of residents posted images of engine pieces landing in their yards, nearby streets, or their houses. Fortunately, no one on the ground was injured by the falling debris.
It should be noted that the aircraft affected by this order is only a small subsection of the 777 family. The aircraft involved in the United incident, registered N772UA, was 26 years old and one of the first B777s produced. Most of these aging B777-200s and -300s have been retired by airlines globally, with only three countries still flying these jets (US, Japan, South Korea).
“Pratt & Whitney is aware of actions taken by Japanese regulatory authorities regarding PW4000-powered Boeing 777 aircraft. We are supporting our operators in Japan and working with the authorities to resolve the situation as quickly as possible. As this is related to an official investigation, we defer to the relevant authorities for future updates.”said Pratt and Whitney in a statement.
Nowadays, most 777s we see on long-haul routes are the 777-300ER or 777-200LR, which are powered by the GE90 engine. These planes remain unaffected by these recent groundings and continue to operate safely around the world.