An American Airlines co-pilot was detained at Detroit Metropolitan Airport after he was suspected of being drunk, federal authorities said.
The Federal Aviation Administration said the co-pilot was held from a Saturday morning flight from Detroit to Philadelphia.
The pilot was detained after arriving at the suburban Detroit airport.
"Police responded with a field Breathalyzer and the co-pilot was indeed over the legal limits," airport spokesman Michael Conway told WWJ's Jason Scott. "They also took him to a local jurisdiction for a more sophisticated machine called the Data Master. On that machine, he also continued to be over the legal limit for a co-pilot." Conway said the co-pilot was released as authorities determine whether charges will be filed.
He said the co-pilot is in his early 50s and from Pennsylvania. Officials wouldn't release more information.
American Airlines spokeswoman Laura Nedbal said in a statement the flight was cancelled and customers were taking other flights.
"Safety is our highest priority and we apologize to our customers for the disruption to their travel plans," Nedbal said.
Airline officials declined to discuss the co-pilot, but say they are assisting investigators.