Is it possible to survive above the summit of Everest? Although it would almost certainly not be possible to climb any higher than an altitude of about 9000m (Everest is 8848m), there are several reports of people surviving unpressurised flights at higher altitudes. At least ten people have stowed away in the wheel bays of long-haul aircraft, which generally fly at altitudes well over 9000m.
This is almost certainly only possible because of the combined effects of extreme cold and unconsciousness, both of which greatly reduces the body's demand for oxygen. The condition could be described as being analogous to hibernation. Sadly, estimates suggest that between 50% and 80% of wheel-bay stowaways do not survive. Perhaps the most compelling account of such a journey is given by Armando Socarras Ramirez, who escaped from Fidel Castro's Cuba in 1969:
The jet engines of the Iberia Airlines DC-8 thundered in ear-splitting crescendo as the big plane taxied toward where we huddled in the tall grass just off the end of the runway at Havana’s Jose Marti Airport. For months my friend Jorge Perez Blanco and I had been planning to stow away in a wheel-well on this flight, No. 904 — Iberia’s once weekly, nonstop run from Havana to Madrid! Now, in the late afternoon of last June 3, 1970, our moment had come.
We realized that we were pretty young to be taking such a big gamble; I was seventeen, Jorge sixteen. But we were both determined to escape from Cuba, and our plans had been carefully made. We knew that departing airliners taxied to the end of the 11,500-foot runway, stopped momentarily after turning around, then roared at full throttle down the runway to take off. We wore rubber-soled shoes to aid us in crawling up the wheels and carried ropes to secure ourselves inside the wheel well. We had also stuffed cotton in our ears as protection against the shriek of the four jet engines. Now we lay sweating with fear as the massive craft swung into its about-face, the jet blast flattening the grass all around us. Let’s run! I shouted to Jorge.
We dashed onto the runway and sprinted toward the left-hand wheels of the momentarily stationary plane. As Jorge began to scramble up the 42-inchhigh tires, I saw there was not room for us both in the single well. I’ll try the other side! I shouted. Quickly I climbed onto the right wheels, grabbed a strut, and, twisting and wriggling, pulled myself into the semidark well. The plane began rolling immediately, and I grabbed some machinery to keep from falling out. The roar of the engines nearly deafened me. As we became airborne, the huge double wheels, scorching hot from takeoff, began folding into the compartment. I tried to flatten myself against the overhead as they came closer and closer; then, in desperation, I pushed at them with my feet. But they pressed powerfully upward, squeezing me, terrifyingly, against the roof of the well.
Just when I felt that I would be crushed, the wheels locked in place and the bay doors beneath them closed, plunging me into darkness. So there I was, my 5 foot 4 inch, 140 pound frame literally wedged in amid a spaghettilike maze of conduits and machinery. I could not move enough to tie myself to anything, so I stuck my rope behind a pipe.
Then, before I had time to catch my breath, the bay doors suddenly dropped open again and the wheels stretched out into their landing position. I held on for dear life, swinging over the abyss, wondering if I had been spotted, if even now the plane was turning back to hand me over to Castro’s police. By the time the wheels began retracting in, I had seen a bit of extra space among the machinery where I could safely squeeze. Now I knew there was room for me even though I could scarcely breathe. After a few minutes, I touched one of the wheels and found that it had cooled off. I swallowed some aspirin tablets against the headsplitting noise and began to wish that I had worn something warmer than my light sport shirt and green fatigues. Up in the cockpit of flight 904, Captain Valentin Vara del Rey, 44, had settled into the routine of the overnight flight, which would last 8 hours and 20 minutes. Takeoff had been normal, with the aircraft and its 147 passengers, plus a crew of 10, lifting off at 170 mph. But, right after lift-off, something unusual had happened. One of three red lights on the instrument panel had remained lighted, indicating improper retraction of the landing gear.
Are you having difficulty? the control tower asked.
Yes replied Vara del Rey. There is an indication that the right wheel hasn’t closed properly. I’ll repeat the procedure. The captain relowered the landing gear, then raised it again. This time the red light blinked out.
Dismissing the incident as a minor malfunction, the captain turned his attention to climbing to the designated cruising altitude. On leveling out, he observed that the temperature outside was 241°F. Inside, the pretty stewardesses began serving dinner to the passengers.
Shivering uncontrollably from the bitter cold, I wondered if Jorge had made it into the other wheel well and began thinking about what had brought me to this desperate situation...
The sun rose over the Atlantic like a great golden globe, its rays glinting off the silver and gold fuselage of Iberia’s DC-8 as it crossed the European coast high over Portugal. With the end of the 4636-mile flight in sight, Captain Vara del Rey began his descent toward Madrid’s Bara Airport. Arrival would be at 8 A.M. local, the captain told his passengers over the intercom, and the weather in Madrid was sunny and pleasant. Shortly after passing over Toledo, Vara del Rey let down his landing gear. As always, the maneuver was accompanied by a buffeting as the wheels hit the slipstream and a 200mph turbulence swirled through the wheel wells. Now the plane went into its final approach; a spurt of flame and smoke from the tires as the DC-8 touched down at about 140 mph.
It was a perfect landing—no bumps. After a brief postflight check, Vara del Rey walked down the ramp steps and stood by the nose of the plane waiting for a car to pick him up, along with his copilot. Nearby, there was a sudden, soft plop as the frozen body of Armando Socarras fell to the concrete apron beneath the plane. Jose Rocha Lorenzana, a security guard, was the first to reach the crumpled figure. When I touched his clothes, they were frozen as stiff as wood Rocha said. All he did was make a strange sound, kind of moan.
I couldn’t believe it at first Vara del Rey said when told of Armando. But then I went over to him. He had ice over his nose and mouth. And his color... As he watched the unconscious boy being bundled into a truck, the captain kept exclaiming to himself, Impossible! Impossible! The first thing I remember after losing consciousness was hitting the ground at the Madrid airport. Then I blacked out again and woke up later at the Gran Hospital de la Beneficencia in downtown Madrid, more dead than alive. When they took my temperature, it was so low that it did not even register on the thermometer. Am I in Spain? was my first question. And then, Where’s Jorge? (Jorge is believed to have been knocked down by the jet blast while trying to climb into the other wheel well and to be in prison in Cuba.)
Doctors said later that my condition was comparable to that of a patient undergoing 'deep-freeze' surgery, a delicate process performed only under carefully controlled conditions. Dr. Jose Maria Pajares, who cared for me, called my survival a 'medical miracle,' and, in truth, I feel lucky to be alive. A few days after my escape, I was up and around the hospital, playing cards with my police guard and reading stacks of letters from all over the world. I especially liked one from a girl in California. You are a hero, she wrote, but not very wise. My uncle, Elo Fernandez, who lives in New Jersey, telephoned and invited me to come to the United States to live with him. The International Rescue Committee arranged my passage and has continued to help me. I am fine now. I live with my uncle and go to school to learn English. I still hope to study to be an artist. I want to be a good citizen and contribute something to this country, for I love it here...
Another remarkable tale of survival at extreme altitude is described in detail here. A champion paraglider, Ewa Wisnierska, was caught in a freak updraft and carried up to 9,946m (32,631 feet). She probably survived because she was unconscious and hypothermic during the exposure.