hawaiian airlines
A 15-year-old stowaway from Santa Clara, Calif., survived in the wheel well of a Hawaiian Airlines flight from San Jose to Maui. wikicommons

Most runaway kids hitch a ride out of town on a bus, train or in the back seat of their friend’s car. And, then there's the 15-year-old boy from Santa Clara, Calif., who scaled a fence on Sunday at San Jose International Airport, snuck into the wheel well of a Maui-bound Hawaiian Airlines flight, and somehow managed to survive the 2,300-mile journey over the Pacific Ocean virtually unharmed.

The unidentified boy's miraculous tale of survival against the odds has captivated a global audience filled with lots of questions, but the big one is: How can anybody survive in an unpressurized, unheated aircraft wheel well? -- where oxygen is in short supply and temperatures can drop as low as minus 80 degrees Fahrenheit.

Aircraft stowaways face countless health risks, including hypothermia, hypoxia, frostbite, deafness and asphyxiation. They also risk falling when the doors of the compartment reopen or being mangled when the undercarriage retracts. Both scenarios could happen quite suddenly and could occur when the stowaway is unconscious.

Nonetheless, some stowaways manage to survive relatively unscathed, largely because the body enters a hibernation-like state, where heartbeats and breaths slow and cellular activity nearly stops. Worldwide, there have been 105 known people since 1947 to have stowed away on flights, and 25 of them survived, according to data kept by the Federal Aviation Administration's Civil Aerospace Medical Institute. Counting the California boy, who survived his ordeal, that's a survival rate of about 24 percent.

What makes the Hawaiian Airlines Flight 45 incident so remarkable is that, in general, the odds of survival decrease in proportion to the duration and altitude of the flight. Yet, the Santa Clara teen reportedly hobbled out onto the tarmac in Maui, virtually unfazed and unharmed.

The FAA believes that he survived temperatures as low as minus 85 degrees Fahrenheit on the high-flying transoceanic voyage, which reached a cruising altitude of about 38,000 feet. To put that in perspective, it would be like climbing well past the top of Mt. Everest and back down to sea level in just a few hours.

Yet, in a 2009 study, “Survival at High Altitude: Wheel-Well Passengers,” which looked at two cases, the FAA documented how it’s entirely possible, if implausible, to survive such conditions. “Despite the lack of pressurization, or personal O2 equipment, the presence of warm hydraulic lines in the wheel-well and the initially warm tires provided significant heat,” it noted in a summary of the report.

“The stable climb of the aircraft enabled hypoxia to lead to gradual unconsciousness. As the wheel-well environment slowly cooled, hypothermia accompanies the deep hypoxia, preserving nervous system viability. With descent, and warming, along with increasing atmospheric oxygen pressure, hypoxia and hypothermia slowly resolved.”

Though survivors are the exception, not the rule, there have been several notable examples in recent years. Here’s a look at cases of wheel-well survival since 1947:

2013

The most recent case of a stowaway surviving a journey in a plane's wheel well occurred last August in Nigeria. Thirteen-year-old Daniel Oikhena thought he’d hitched a ride to the U.S. but instead was arrested at Lagos Airport after flying in the tire hole of an Arik Air plane out of Benin. Authorities credited the boy’s survival to the short duration and low altitude of the flight.

2010

Poor weather likely helped a 20-year-old Romanian man survive his nearly two-hour trip from Vienna to London in June of that year, hidden in the landing gear of a plane. The Boeing 747 flew at a lower altitude than normal due to thunderstorms over Central Europe, offering more oxygen and warmer temperatures than the average stowaway encounters.

2002

Cuban stowaway Victor Alvarez Molina endured temperatures below minus 40 degrees Fahrenheit on a four-hour flight from Cuba to Montreal that December. The asylum seeker was detained upon arrival, but later became a Canadian citizen. Authorities believe he was only able to survive the journey because of a leak in a compartment pipe, which allowed warm air to seep into the wheel well.

2000

Twenty-four-year-old Tahitian Fidel Maruhi miraculously lived to tell the tale of a 4,000-mile, 7.5-hour journey from Tahiti to Los Angeles in that long ago August. Airport staff found him unconscious and suffering from severe hypothermia while refueling the Paris-bound Boeing 747 at Los Angeles International. Maruhi reportedly had a body temperature of just 79 degrees (6 degrees colder that what’s typically considered fatal) but was otherwise unharmed by the experience.

1996

In what is, perhaps, the greatest survival story of them all, a 22-year-old Indian man survived a 10-hour, 4,200-mile British Airways flight from Delhi to London in October 1996. His 19-year-old brother, who also stowed away in the nose wheel well, wasn't so fortunate. The elder brother suffered from severe hypothermia but is thought to have survived because his body went into “suspended animation,” a frozen state that’s virtually as close to death as you can get without passing away.

Other stowaways have survived flights from Bogotá to Miami (1993), Trinidad to Toronto (1990), Panama to Miami (1986), Havana to Madrid (1969), Bogotá to Mexico City (1966), and Lisbon to Natal (1947).