- A 4-foot-long tool was left inside the engine of an Airbus A380, a safety report found.
- The Qantas jet flew 294 hours of flights with the tool still inside, Australian authorities said.
- The investigation said that an engineer left the tool there as they thought it would be needed later.
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 Thursday in an Australian Transport Safety Bureau investigation report.
It said that a nylon tool, 1.25 meters or around four 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.
In its conclusion, the report said, "Foreign object debris and damage can pose a significant threat to the safe operation of aircraft."
The investigation said that an engineer left the tool in the engine inlet because they believed it would be needed by somebody else later. Subsequent inspections after their task failed to spot the tool.
"The ATSB investigation found that maintenance engineers did not notice the tool had been left in the engine's low-pressure compressor case when conducting checks for foreign objects at the completion of the borescope inspection task," ATSB Chief Commissioner Angus Mitchell said.
"Further, maintenance engineers did not commence the lost tool procedure once the tool had been identified as missing, and the certifying engineer released the aircraft for service with the tool unaccounted for."
After the tool was discovered, Qantas Engineering briefed staff on the importance of returning all tools, the ATSB said.
Qantas did not immediately respond to a request for comment from Business Insider, sent outside normal Australian working hours.