United Airlines Flight 1175
The damage to the right engine after the engine failure | |
| Incident | |
|---|---|
| Date | February 13, 2018 |
| Summary | Emergency landing following engine failure in cruise |
| Site | |
| Aircraft | |
| N773UA, the aircraft involved in the incident, seen in 2015 | |
| Aircraft type | Boeing 777-222 |
| Operator | United Airlines |
| IATA flight No. | UA1175 |
| ICAO flight No. | UAL1175 |
| Call sign | UNITED 1175 |
| Registration | N773UA |
| Flight origin | San Francisco International Airport, San Francisco, California, United States |
| Destination | Daniel K. Inouye International Airport, Honolulu, Hawaii, United States |
| Occupants | 378 |
| Passengers | 363 |
| Crew | 15 |
| Fatalities | 0 |
| Survivors | 378 |
On February 13, 2018, around noon local time, a Boeing 777 operating as United Airlines Flight 1175 (UA1175), experienced an in-flight separation of a fan blade in the No. 2 (right) engine while over the Pacific Ocean en route from San Francisco International Airport to the Daniel K. Inouye International Airport, Honolulu, Hawaii. During level cruise flight shortly before beginning a descent from flight level 360 (roughly 36,000 feet or 11,000 meters), and about 120 miles (100 nmi; 190 km) from the destination, the flight crew heard a loud bang, followed by a violent shaking of the airplane, followed by warnings of a compressor stall. The flight crew shut down the failed engine, declared an emergency, and began a drift-down descent, proceeding direct to the Daniel K. Inouye International Airport where they made a single-engine landing without further incident at 12:37 local time. There were no reported injuries to the 378 passengers and crew on board and the airplane damage was classified as minor under National Transportation Safety Board (NTSB) criteria.
NTSB investigators traveled to the scene to begin an incident investigation. They found a full-length fan blade fracture in the No. 2 (right) engine, a Pratt & Whitney (P&W) PW4077 turbofan. Its installed set of hollow-core fan blades had undergone two previous overhauls at P&W that included a thermal acoustic imaging (TAI) internal inspection that is intended to prevent this type of failure. The right engine nacelle lost most of the inlet duct and all of the left and right fan cowls immediately after the engine failure. Two small punctures were found in the right side fuselage just below the window belt with material transfer consistent with impact from pieces of an engine fan blade. The damage was eventually repaired and the aircraft returned to service. Improved procedures for TAI inspection were implemented by P&W, increased frequency of TAI inspection was required by regulators, and a redesign of the inlet duct was also initiated by Boeing, all as a result of this incident and investigation.