DUBLIN (AFP) - A trans-Atlantic Air Canada flight diverted to Ireland after the co-pilot became "belligerent" and had to be removed from the cockpit, an official report said on Wednesday.

An Irish transport ministry report described the incident as "serious" and said a flight attendant with a commercial pilot's licence took the place of the first officer on the Boeing 767 with nine crew and 146 passengers flying from Toronto to London.

The plane made an emergency diversion to Shannon airport in Ireland on January 28 after the co-pilot had to be removed from the cockpit by crew members when he became "belligerent and uncooperative", it said.

The unnamed 58-year-old captain said his first officer, who was also not named, appeared "quite harried" when he turned up late before departure.

After take-off, the first officer said several times he was "very tired" and the commander suggested he take a rest break.

As the flight approached the mid-Atlantic, he "began conversation which was rambling and disjointed in nature and not at all in character, as the commander knew him to be an outgoing and talkative person," the report said.

Later, his behaviour "became belligerent and uncooperative which convinced the commander he was now dealing with a crew member who was effectively incapacitated," it added.

When ordered to secure his seat belt, he was "unresponsive".

Flight crew were then ordered to remove him from the controls and he was treated by British and Canadian doctors on board who reported he was in a "confused and disorientated state".

Air accident investigator Leo Murray said the captain had used "tact and understanding" to keep control of the situation.

The co-pilot was treated in an Irish hospital for 11 days before being flown home for further care.

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