The pilot of a small plane between Colorado and California was having trouble breathing and was unable to talk. His wife took over the controls and, with the help of another pilot, was able to put the plain in autopilot and guide it to a nearby airport.The husband was able to regain himself and landed the plane in Farmington, NM..  Apparently, the pilot was hypoxic and the high altitude caused the problem..

"I was terrified — terrified," she said.

The full story is here.