China News Service, February 24th, a comprehensive report that a United Airlines Boeing 777 airliner had an engine failure during the flight. As of now, all Boeing 777 airliners using the same type of engine have been grounded worldwide.
The National Transportation Board (NTSB) said that preliminary assessments showed that the accident was related to the metal fatigue of the fan blades in the engine.
On the 20th, 4 minutes after a United Airlines Boeing 777-200 passenger plane took off from Denver International Airport in Colorado, the right engine of the plane malfunctioned and exploded and burned, causing the external rectifier ring to fall off.
According to Reuters, after preliminary analysis of flight data and cockpit voice recorders, NTSB Chairman Robert Sumwalt said that preliminary assessments showed signs of damage to engine fan blades were consistent with metal fatigue.
He also said that the fuselage of the aircraft was slightly damaged in the accident, but there was no structural damage.
He said that it is not clear that the cause of this incident is consistent with the engine failure of another United Airlines passenger plane in February 2018, when the incident was caused by the fatigue fracture of the fan blades.
Sumwater said: "United Airlines has grounded all affected aircraft using these engines. I know the FAA is also taking quick action, and Pratt & Whitney has reissued or revised its service announcement." It added that the NTSB will investigate why the fairing was separated from the airliner and why a fire broke out, although there are signs that the engine's fuel has been cut off.
According to the report, the fan blades of the Pratt & Whitney PW4000 engine in the accident have been sent to Pratt & Whitney's laboratory and will be inspected under the supervision of NTSB investigators on the 23rd local time.
After the accident, Boeing issued an emergency statement on the 21st, recommending that all Boeing 777 passenger aircraft equipped with Pratt & Whitney PW4000 engines be grounded globally, a total of 128 aircraft, including 69 active aircraft and 59 reserve aircraft, until the United States Federal Airlines Appropriate inspections required by the FAA are completed.
According to Reuters, Boeing 777 passenger aircraft equipped with this engine account for less than 10% of the 1,600 Boeing 777 fleet.
In addition to United Airlines, companies such as Japan Airlines and All Nippon Airways, Korean Air, Asiana Airlines, and Jin Airlines have all grounded related aircraft under regulatory requirements. The British Transport Secretary Grant Sharps (Grant Shapps) has also announced that the UK has grounded the Boeing 777 passenger aircraft with this type of engine.
Agence France-Presse reported that a Boeing spokesperson confirmed on the 22nd that all Boeing 777 passenger aircraft using this type of engine have been grounded worldwide.