CNN reports a flight from Glasgow, Scotland to Newark, New Jersey was canceled Saturday.
The move came after two pilots were arrested on suspicion of being intoxicated.
Police Scotland said two men were arrested at the airport before boarding.
The men, aged 61 and 45, remain in police custody pending a court appearance on Tuesday.
We hold all of our employees to the highest standards and have a strict, no tolerance policy for alcohol. Jonathan Guerin United Airlines spokesman