Passengers have spoken of the terrifying moment a United Airlines plane's engine began to disintegrate mid-air.
The flight, from San Francisco to the Hawaiian capital Honolulu, was forced into an emergency landing after a "loud bang" was heard before the plane began to "shake violently" around 30 minutes into the journey.
Erik Haddad, a Google engineer, shared photos and video showing the exposed engine shaking after its covering had broken away.
He joked: "I don't see anything about this in the manual."
Maria Falaschi described it as the "scariest flight of my life" but praised pilots and crew for their handling of the incident.
"There was a loud bang ... and then the plane really started shaking," Allison Sudiacal, who was travelling with her four-month-old son, told NBC affiliate KHNL of Honolulu.
"It was like rattling, and the plane was kind of shaking, like boom, boom, boom," she said, adding that aircraft crew kept everyone informed. Her husband, Tim, told the station that the flight was "absolutely terrifying."
United Airlines said the flight landed safely in Honolulu and that all passengers left the plane normally.
The Federal Aviation Administration has said it will investigate the incident.