An Air Canada flight made an emergency landing in the Irish Republic after a pilot apparently suffered a breakdown.
Air Canada says a crew member was taken ill
A passenger said the pilot was carried from the plane shouting and swearing, saying he wanted to talk "to God".
The flight from Toronto to Heathrow landed at Shannon airport after its crew declared a medical emergency. Passengers flew on to London later.
Air Canada has confirmed that a crew member was unwell, but did not confirm he was suffering mental problems.
"At no time were the safety of the passengers or crew in question," said an Air Canada spokesman.
"The flight was met by medical personnel and the individual is now in care."
One of the passengers, Sean Finucane, said he saw the co-pilot being carried into the cabin in restraints.
"He was very, very distraught. He was yelling loudly at times," he told the Canadian Broadcasting Corporation.
"He was swearing and asking for God and very distressed. He basically said he wanted to talk to God."
Passengers were put up in hotels while another crew was found. They eventually arrived in London eight hours late.