A co-pilot on a charter plane in northern Michigan has been arrested after a colleague suspected that he was drunk.

Traverse City police Capt. Kevin Dunklow says a breath test Thursday showed the co-pilot, a 35-year-old Florida man, had a blood-alcohol level of 0.30, nearly four times the legal threshold for driving.

The co-pilot flies for Talon Air, which declined to comment. The plane didn't leave Cherry Capital Airport in Traverse City.

Separately, an American Airlines co-pilot accused of trying to fly while drunk pleaded no contest Wednesday at a Detroit-area court. He was placed on probation.