SYRACUSE, N.Y. -- A New York medical examiner says an American Airlines pilot who became ill while flying from Phoenix to Boston died from natural causes.
The Onondaga County medical examiner's office on Monday night announced the determination in the death of 57-year-old Capt. Michael Johnston. Officials say the determination was made after an autopsy and preliminary toxicology tests. No other details have been released.
CBS affiliate KUTV reported Johnston has been flying for well over 25 years according to his family. BJ Johnston, his wife, said she's been told that her husband likely died of a heart attack.
She said her husband had a double bypass surgery in 2006. Since that time he has been required to get a physical every six months to make sure he was healthy enough to fly.
"He has had problems with his heart," Johnston's wife told KUTV. "He seemed perfectly fine."
Johnston said her husband was in good health when he left recently to begin flying.
American Flight 550 left Phoenix at 11:55 p.m. local time Sunday and was diverted mid-flight, landing shortly after 7 a.m. EDT, American spokeswoman Andrea Huguely said. After the captain was stricken, the first officer took over with 147 passengers and five crew members onboard.
In audio from the cockpit obtained by CBS Boston by Live ATC.net, which provides live air traffic control broadcasts, the co-pilot is heard calling the control tower, "A medical emergency. Captain is incapacitated, request handling for runway one zero landing."
In a recording of his exchange with the tower, he expresses concern over whether ambulance medics can get on the plane quickly. He is assured they can and is told to go into a gate where the medics would meet the plane.
"We are incredibly saddened by this event, and we are focused on caring for our pilot's family and colleagues," the Fort Worth, Texas-based airline said.
A replacement crew was sent to Syracuse, and the plane, an Airbus A320, landed in Boston at 12:30 p.m.
Aviation experts said there was never any danger to passengers because pilots and co-pilots are equally capable of flying.
Ex-airline pilot John Cox, an aviation safety consultant, said when one pilot becomes unable to fly the other will rely on help from the plane's automated systems and get priority treatment from air traffic controllers.
"The passengers were not in danger, absolutely not," he said.
Passenger Louise Anderson, heading from Reno, Nevada, to Boston via Phoenix, said she had dozed off on the flight.
"What I woke up to was the flight attendant telling us we were making an emergency landing because the pilot was ill," she said.
She said rumors of the pilot's death circulated in the Syracuse airport but were confirmed only by an announcement on their makeup flight to Boston.
Anderson said the mood on board then was somber, but she commended the crew's handling of a tragic situation.
Airline pilots must pass physical exams every 12 months, every six months for captains 40 or older.
Captains and co-pilots usually take turns flying and doing takeoffs and landings, said former airline pilot James Record, who teaches aviation at Dowling College in Oakdale.
"The advantage to that is the co-pilot gets an equal amount of experience and the captain gets to see how the other guy flies," he said.
Record noted the co-pilot remained calm while describing the emergency and requesting permission from air traffic controllers to land.
"He was doing what he's trained to do -- fly the plane," Record said. "He was probably more concerned with the health of his buddy, his crew member," than his ability to fly.
Modern airliners are capable of largely flying themselves. There's debate in aviation circles about whether over-reliance on automation is eroding pilots' flying skills. Incidents like Monday's help ensure regulators won't allow unmanned cockpits or unaccompanied pilots anytime soon.
Johnston was a graduate of Brigham Young University. He began his career with America West Airlines in 1990 as a first officer and later was upgraded to captain. He was married and is survived by a wife and children.