TWO pilots in charge of a 325-seat passenger long-haul flight fell asleep in the plane’s cockpit, leaving it on auto-pilot, a report reveals.

The pilots admitted their actions shortly after take-off in an Airbus A330 operated by a British based airline on 13 August, The Sun reported .

The UK Civil Aviation Authority revealed that the pilot and co-pilot had agreed to take turn having short naps, leaving the plane on auto-pilot.

However, one of them woke up to discover that they had both been asleep at the same time and did not know how long the plane had been unsupervised.

The pilots voluntarily reported the blunder to the CAA, which has hidden the name of the airline they work for in a bid to encourage other whistleblowers to speak out.

The CAA’s report said the flight crew were suffering from symptoms of “severe fatigue”.

A spokesman for the CAA said it would be “very surprised” if any disciplinary action was taken against the pilots.

“Perhaps the airline in question may have looked at their roster or shift system as a result”, the spokesperson said.

“In potentially critical safety situations like this, we aim to learn from what happened and ensure it will not happen again.”