Such Great Heights

How to Hitchhike a Plane—and Survive

A runaway teen hitched a ride in the wheel well of a plane that reached 38,000 feet and subzero temperatures. How the hell did he get out alive?

Hawaiian Airlines/AP

A 16-year old boy brought respiratory physiology to the front page yesterday by surviving a stint as a stowaway in the unpressurized, non-oxygenated hub of the wheel well in a Hawaii Airlines plane.

The airplane flew at an altitude higher than that of Mount Everest—about 38,000 feet compared to Everest at 29,000 feet. The boy also endured temperatures of negative 40 degrees Fahrenheit and space more cramped than coach class. Upon landing, he was reportedly spotted wandering the tarmac with only a comb in his pocket.

How did he survive? The numbers are against him—the data is that 105 people are known to have tried this since 1947, and just 25 have lived. The others have frozen to death, died of lung injury, or been crushed by the wheel mechanism. A summary of 10 cases culled from New York Times reports filed between 1947 and 1993 by experts from the FAA and fittingly enough, Wright State University in Dayton, Ohio, describes grisly details from 10 wheel well stowaways (PDF).

That article and a few similar ones, including a first-person recollection of a Cuban refugee, help explain how on earth a person can survive at heights higher than Everest, where trained people moving slowly and deliberately with assistance, pills, and oxygen too often fail. Simply stated, the harshness of the elements conspires to help, rather than hinder, the lucky few.

Right now, we are all breathing air that is about 21% oxygen. Our respiratory apparatus—the alveolus (the tiniest air-pocket in our lung), the arteriole (the tiniest artery), and the surfactant (a lubricating liquid in the airway)—is well-primed for the complex physiologic act of oxygen exchange from inspired air right into our bloodstream. Birds do it, bees do it, even educated flees do it—thousands and thousands and thousands of times a day.

At Hawaii Airlines altitude, though, things are quite a bit different. The percent of oxygen is the same, more or less, but there is much less atmosphere up there. The upper atmosphere lacks pressure. Here on terra firma, atmospheric pressure is about 760 millimeters of mercury, but in Sandra Bullock Gravity-land (OK, not that high but still way up there), where jets fly, the atmospheric pressure is about 200 millimeters of mercury. The body isn’t adapted to this at all. Because the coin of the realm turns out not to be oxygen, exactly, but rather the “partial pressure” of oxygen—a simple product of the percent of oxygen present (21% either place) and the atmospheric pressure. At low partial pressures, oxygen can’t much enter the bloodstream.

So even if you’ve got plenty of oxygen to sip, the respiratory apparatus—the alveolus, arteriole, and surfactant—doesn’t work right. In the extreme, the human body reaches “Armstrong’s limit”—the point at which all the liquid components of the human body, including surfactant and saliva (though excluding blood) boil at normal temperatures. Granted, Armstrong’s limit is around 60,000 feet, but as any veteran watcher of movies about hot shot top gun pilots knows, Johnny or Tommy or Biff was warned not to climb that high! But tried it anyhow! And died an ugly death, courtesy of Armstrong’s limit.

The point is that atmospheric pressure is critical, not oxygen percentage, making the wheel well, which unlike the inside of the airplane is not pressurized, a particularly dangerous place to stow away. But that’s where a confluence of dangers sometimes works to some small advantage.

The extreme cold of the upper atmosphere—wheel well riders have had body temperatures recorded at around 80 degrees Fahrenheit—slows the body’s cellular activities, sharply reducing the demand by cells for oxygen. A normal person becomes unconscious—comatose really—in this extreme cold. Just as once in a while, a drowning victim will survive because the extreme cold water acted in a similar fashion to suspend normal function, so too does some lucky wheel well stowaway occasionally make it back to the ground alive. According to the FAA data, younger men, like this week’s 16-year-old, are the survivors.

Which brings up the real question: Why did the kid leave Santa Clara and head out to Hawaii in such a fashion? Sure, people have been running away for at least as long as Huck Finn decided he had to “light out for the Territory ahead of the rest.” The teen years are a restless, miserable time for many.

But hopefully, in all of the coverage of airplanes and wheel wells and FBI reports, those involved will focus not on the recklessness of the act, but rather on the poor kid himself, who surely was lost long before he was seen wandering alone on the runway in Hawaii.