Safety Check
Higher Isn’t Always Better

Just because modern jump planes can safely fly at 25,000 feet and above doesn’t mean that a skydiver can. Those who believe that all they need for a high-altitude jump is a hose from an on-board oxygen system to suck on while climbing to altitude could be dead wrong.

Hypoxia, or oxygen deficiency, can easily occur at altitudes below 15,000 feet. The chances increase dramatically as the plane climbs higher. A quick climb to altitude makes things even worse, and the effects of hypoxia can remain for up to 30 minutes.

An unconscious skydiver is a danger to himself and others, even if he should by chance recover at lower altitudes in thicker air. And hypoxia is only one of many problems of jumps from higher altitudes.

There’s also decompression sickness, or the bends, which can be extremely painful and even fatal if not treated quickly. Going up quickly from sea level to high altitudes produces similar effects as coming up too quickly on a SCUBA dive. There is also the likelihood of air embolisms, which can be every bit as debilitating or fatal as decompression sickness.

Also, canopies open harder at higher altitudes, due to the greater difference between freefall speed and open canopy speed in thinner air. If a canopy opens prematurely up high, the results can be a broken parachute system or a broken jumper. And that jumper now stuck under an open parachute may be faced with temperatures much lower than those in which he has ever
tried to operate a parachute system, not to mention having to do so with an expiring or non-existent oxygen supply.

Think about this. Military high-altitude, low-opening (HALO) jumpers pre-breathe 100 percent aviator-grade oxygen for at least a half hour before going above 18,000 feet. During the climb, they also have an oxygen safety officer who monitors the condition of the oxygen console and jumpers and an Air Force physiology technician to ensure their medical welfare. And before they ever are considered for HALO training, they have to undergo a special, tough flight physical and attend a high-altitude evaluation and familiarization course, which includes a hypobaric chamber ride, simulating high-altitude conditions.

Skydivers considering a high-altitude jump should not be lured into believing that this is just another skydive, but with onboard oxygen in case dizziness occurs. This is serious business. There are good reasons why the HALO jumpers go to so much trouble. Short of joining the Army, a good place to begin a high-altitude quest is with Section 6 of the Skydiver’s Information Manual.
--Chris Needels

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