A Qantas Airbus A380 flew for hundreds of hours before it was discovered a tool had been left inside one of its engines.
The incident came to light on Thursday in an Australian Transport Safety Bureau investigation report.
It said that a nylon tool, 1.25 metres (4 feet) long, was discovered wedged inside the engine during a scheduled maintenance check in Los Angeles on January 1.
The California city is one of four destinations served by the Australian flag carrier’s A380 jets.
The ATSB investigation found that the tool had been inside one of the plane’s four engines since a previous maintenance check on December 6 last year.
It added that the superjumbo jet had flown 34 cycles, or 294 hours, with the nylon tool in the engine.