An American Airlines pilot died on a red-eye flight from Phoenix to Boston overnight, forcing the first officer to step in and land the plane.
USA Today reports that the pilot died about four hours into Flight 550, which then diverted to Syracuse.
"In a recording of a conversation with air traffic control, Flight 550's first officer can be heard calling in the emergency while saying the captain had become incapacitated," the report says.
"Syracuse, American 550, medical emergency, captain is incapacitated, request handling for runway," the co-pilot said.
American Airlines spokesman Ross Feinstein said the captain died, though the immediate cause of the pilot's death could not be confirmed.
"We are incredibly saddened by this event, and we are focused on caring for our pilot's family and colleagues," Feinstein said.
The report says the captain and first officer are each capable of flying commercial airliners, and the Federal Aviation Administration requires two crew members in the cockpit at all times for just such an emergency.