I’ll stick with my parachute, thanks

Via Daily Kos, I came across this interesting article in Popular Mechanics: How to Fall 35,000 Feet — and Survive:

You have a late night and an early flight. Not long after takeoff, you drift to sleep. Suddenly, you’re wide awake. There’s cold air rushing everywhere, and sound. Intense, horrible sound. Where am I?, you think. Where’s the plane?

You’re 6 miles up. You’re alone. You’re falling.

Things are bad. But now’s the time to focus on the good news. (Yes, it goes beyond surviving the destruction of your aircraft.) Although gravity is against you, another force is working in your favor: time. Believe it or not, you’re better off up here than if you’d slipped from the balcony of your high-rise hotel room after one too many drinks last night.

It’s a rather overly dramatic article, but very entertaining and thought-provoking.  As a skydiver, I’ve often wondered what would be my strategy if I had a total malfunction of both my main and reserve parachutes.

Reassuringly, the article more or less backs up my thoughts:

With a target in mind, the next consideration is body position. To slow your descent, emulate a sky diver. Spread your arms and legs, present your chest to the ground, and arch your back and head upward. This adds friction and helps you maneuver. But don’t relax. This is not your landing pose.

The question of how to achieve ground contact remains, regrettably, given your predicament, a subject of debate. A 1942 study in the journal War Medicine noted “distribution and compensation of pressure play large parts in the defeat of injury.” Recommendation: wide-body impact. But a 1963 report by the Federal Aviation Agency argued that shifting into the classic sky diver’s landing stance—feet together, heels up, flexed knees and hips—best increases survivability.

As I understand it, the main cause of death in skydiving accidents is that the force of impact rips the aorta right off the heart.  Minimizing the force of impact means minimizing the speed of impact, which means you should maintain the “belly-to-earth” position to keep your speed down.  On the other hand, the best way to absorb force is to impact feet first.  To maximize survival, one should transition from belly-to-earth to feet-to-earth at the very last moment before impact.  This is something a skydiver could possibly get away with, but would be very hard for most folks.

With that in mind, another section is a little curious:

Statistically speaking, it’s best to be a flight crew member, a child, or traveling in a military aircraft…Crew survival may be related to better restraint systems, but there’s no consensus on why children seem to pull through falls more often. The Federal Aviation Agency study notes that kids, especially those under the age of 4, have more flexible skeletons, more relaxed muscle tonus, and a higher proportion of subcutaneous fat, which helps protect internal organs. Smaller people—whose heads are lower than the seat backs in front of them—are better shielded from debris in a plane that’s coming apart. Lower body weight reduces terminal velocity, plus reduced surface area decreases the chance of impalement upon landing.

Emphasis mine.  I don’t necessarily find the survivability of children that mysterious.  People often like to say, “It’s not the fall that kills you, it’s the sudden stop at the end.”  That itself isn’t really true, either — if you were subjected to a force that affected the your body equally, interior and exterior, you could survive any number of g’s.  The problem is, loosely speaking that the bottom of your body gets stopped by the ground, while the top of your body keeps moving — you get crushed by your own body.  A lighter-weight, younger person would feel less of a “self-crushing force”.

It’s a good article, nevertheless, and worth reading.  Strangely, the article just makes me want to get out and skydive, especially considering I’ve been grounded due to weather and travel for a couple of months!

This entry was posted in ... the Hell?, General science. Bookmark the permalink.

1 Response to I’ll stick with my parachute, thanks

  1. The Wife says:

    I’m not reading this…

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