An American Airlines co-pilot was arrested prior to a flight on Saturday morning for suspected intoxication, officials said.
The pilot failed a breathalyzer test, and his blood alcohol content was over the legal limit for a pilot, ABC News reported, citing Michael Conway, director of public affairs at the Detroit Metropolitan Airport.
The flight, which was scheduled to travel from Detroit to Philadelphia, was cancelled.
"This is a serious matter and we are assisting local law enforcement and the Federal Aviation Administration with the investigation,"American Airlines said in a statement reported by the network. "We will handle this matter appropriately as the safety and care of our customers and employees is our highest priority."
The co-pilot's name has not yet been released.