A pilot was arrested on suspicion of being drunk shortly before his flight from Manchester Airport to Chicago was due to take off.
The pilot was due to fly from Manchester to Chicago
American Airlines said the 45-year-old pilot, from Ohio, had been arrested as he reported for duty at Manchester Airport on Saturday morning.
He was released on bail pending the results of tests and is to report to Greater Manchester Police on Tuesday.
The airline has begun an internal investigation into the arrest.
The flight left Manchester after a 55 minute delay, at 1125 GMT.
It was due to stop in New York to supplement the original crew.
The Boeing 767-300 was carrying 198 passengers and 11 crew.
The airline said in a statement: "An investigation into the circumstances of this event was immediately launched by the airline.
"American Airlines has apologised to all passengers for the inconvenience caused and has made alternative arrangements for those with connecting flights.
"Our primary concern is for the safety and comfort of our passengers and crews.
"American Airlines has strict policies on alcohol and substance abuse and holds its employees to the highest standards.
"Employees at all levels of the company are not allowed to be on duty whilst under the influence of drugs or alcohol and regular screening is carried out."