It's every passenger's worst nightmare - the pilot is taken ill and you're left to fly the plane.
But that's exactly what happened to one woman, who found herself having to take control of a plane after the pilot, her husband, became incapacitated.
Despite having never flown an aircraft before, she managed to fly the plane through mountainous territory to safety, thanks to the guidance of another pilot in the area.
The Federal Aviation Administration released the audio and a transcript of the incident, which occured on a flight between California and Colorado.
'Have you ever flown an aircraft before?' asked the other pilot, who was in the area and was in radio contact with the woman. 'Do you have any experience?'
'No,' the woman replied.
The guiding pilot then instructed the woman on how to turn on the autopilot function and begin a controlled descent.
'Hang on, hang on. I'm trying to get him to put auto ... autopilot,' the woman said. 'I don't know how to do this.'
The FAA has not released the names of the pilot and the passenger, citing privacy concerns, and the specifics of the man's medical problem weren't available.
Speaking on US television station KCNC after the incident, the woman said: 'I was terrified - terrified.'
During a routine conversation earlier in the flight, an air traffic controller - Charlie Rohrer - noticed that the single-engine plane's 70-year-old pilot appeared to have difficulty breathing, KCNC reported. The woman said her husband was slurring his speech and was unable to push the buttons.
The plane began to make erratic maneuvers, and as Rohrer tried to get back in touch with the small plane, the pilot of another plane in the area - who was on the same radio frequency - offered assistance to Rohrer.
With his help, the woman eventually flipped on the autopilot function, though she already had directions for the emergency parachute in her lap, just in case.
At one point, the plane swerved away from its emergency landing route and headed toward the high terrain of the San Juan mountains in southwestern Colorado. Rohrer told the woman to turn away from the mountains.
Eventually the plane headed toward safer, lower terrain and began dropping in elevation. The woman said her husband was becoming more lucid.
The husband came on the radio and indicated he would continue his course to Colorado Springs. But Rohrer warned that, to do that, he would have to climb to 17,000 feet and risk becoming hypoxic again.
'OK, you're still not, uh, sounding like you're very coherent,' Rohrer said, suggesting he landed instead.
The plane eventually landed safely, without any injuries.
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