It has emerged that a passenger helped to land a plane at Dublin Airport early yesterday morning.

The Lufthansa Boeing 747 was en route from New York to Frankfurt with 264 passengers on board when the first officer became "incapacitated" while it was flying over the Atlantic.

Once the crew announced that the plane was being diverted, the passenger asked why, and offered his assistance.

The German national, thought to be a qualified pilot, then helped bring the plane down safely in an emergency landing at Dublin Airport shortly before 6am yesterday morning.

The Air Accident Investigations Unit is examining the incident.

Kevin Doyle of the Evening Herald said that Lufthansa has branded the helpful passenger a "hero".

"The understanding is that the passenger in question was an off-duty qualified pilot who had some experience with a different airline, so he has no connection at all with Lufthansa, but he had flown planes in the past," he said.

"Lufthansa said that they were very lucky to have a man with his qualifications on board at the time."

The Air Accident Investigation Unit (AAIU) of the Department of Transport has been notified and is investigating.

Experts from the AAIU attended the plane after it touched down in Dublin.

“Whenever you have any sort of medical issue on board, whether it’s a doctor or appropriately qualified person, that’s always appreciated. The flight would have been operated as per procedures and safely even if the off-duty pilot had not been there,” the Lufthansa spokeswoman added.