The aircraft's co-pilot took control of the plane after the captain became incapacitated, and landed safely at Syracuse Hancock International Airport shortly after 7am.
The plane, an Airbus A320, was en route from Phoenix to Boston when it was diverted to Syracuse in response to the medical emergency.
"Unfortunately, our pilot passed away," American Airlines said in a statement. "We are incredibly saddened by this event, and we are focused on caring for our pilot's family and colleagues."
