An Air Canada flight attendant took over some cockpit duties earlier this year when the flight's co-pilot had a nervous breakdown, an official report said Wednesday.

Another flight attendant received wrist injuries while helping to restrain the co-pilot, said the report from Ireland's Air Accident Investigation Unit (AAIU).

The incident happened on Jan. 28 as a London-bound Air Canada flight was over the Atlantic Ocean. The flight, carrying 146 passengers and nine crew members, had departed from Toronto's Pearson airport.

According to the report, the pilot said his co-pilot had arrived at the Toronto airport later than usual and appeared "quite harried."

After complaining of fatigue and taking a couple of rest breaks, the co-pilot became "belligerent and unco-operative" and was forcibly removed from the cockpit by other crew members, said the report. Two doctors on board the flight examined the co-pilot and reported he was in a confused and disoriented state.

The pilot requested an emergency landing at Shannon Airport, west of Limerick, and asked the flight crew to find out whether there were any other pilots on board.

A flight attendant with a commercial pilot's licence took the co-pilot's seat to help land the Boeing 767. The pilot told Irish investigators she provided "useful assistance" and was "not out of place" in the co-pilot's chair, said the report.

The report also commends the pilot and flight crew for their calm and professional manner.

"The commander, realizing he was faced with a difficult and serious situation, used tact and understanding and kept control of the situation at all times," said the report.

"The situation was dealt with in a professional manner.… As such the commander and flight attendants should be commended for their professionalism in the handling of this event."

Irish newspapers reported the co-pilot was forcibly removed from the plane by fellow crew members and a passenger who was a member of the Canadian Forces. He was taken to the psychiatric unit of a nearby hospital and remained there for 11 days before returning to Canada with his wife, who had joined him in Ireland. He is recovering, said the report.

The co-pilot was an experienced pilot whose positive medical assessment was dated October 2007, said the report.