Aerosoftware - skydiving

Bogey at 12 O'Clock

by Jan Meyer

"I just deployed my parachute, felt line stretch and there I was, face to face with another jumper. He was coming at me with a closing speed of at least fifty miles per hour. I knew there would be a collision. What should I do???

Track better next time. Dump lower next time. What will I do to make it to a next time?? It's too late to steer away. I know we'll collide. I was taught to spread my arms and legs out, so I wouldn't go through the lines. But, I couldn't do that. I saw a canopy approaching at 50 mph, and instinctively, I got into the tiniest tuck position I've ever done. I heard "SWISH" as I brushed by the lines and came clear out on the other side of this other guy's parachute. I heard someone telling me to cutaway first. I did and then deployed my reserve. I saw the other jumper cutaway and deployed his reserve too." ---Several Jumpers' Stories.

Canopy collisions are occurring all too often at most DZs across the world. Jumpers open too close to each other for a variety of reasons. These reasons include poor tracking, groups from different aircraft exiting too close to each other or carelessness. Diligent tracking and clear waveoffs can reduce the likelihood of canopy collisions.

Over the years, many jumpers have suggested action plans for various emergency situations, such as a canopy collision. The prevailing thoughts on emergency procedures for canopy collisions is to "spread your arms and legs to avoid going through the lines", as stated in PIA's Safety Poster #3, Skydiving Basis Rules of the Air. This action plan has been taught worldwide for a very long time.

This canopy collision procedure for sport parachutists came from the military. When military personnel were rapidly deployed into a DZ by parachute, many paratroopers, under T-10s, crashed into each other. The military troops found that they could hit the other fellow's lines and bounce off, if they spread their arms and legs to prevent themselves from passing through the lines of the other troops' parachute. This was great because paratroopers had (and still do) shot and halves for canopy releases. It is difficult to quickly jettison a main attached by shot and a halves. (Standard procedures call for paratroopers, not to cutaway, but deploy a chest mounted reserve by throwing it out into clear air).

These procedures were transferred to sport parachuting in the 1940s and 1950s. Back then, mains were round, cutaways were not always done and if they were done, they were done with a shot and a half system, and closing speeds for head-on collisions were about 10 mph. The plan to "spread your arms and legs to avoid going through the lines" was good under these conditions.

Progress in design has improved performance of sport parachuting equipment. Today, sport parachutists have a single, quick and easy, velcroed handle to pull to release the main parachute or they have a pull on a SOS ripcord handle. (This is no big news item to you, but only military freefall jumpers have a cutaway handle.) Sport parachutists also have advanced parachute designs that give airspeeds 20 to 30 mph. Many of these advanced parachutes use microlines, too.

What has equipment got to do with an emergency procedure for imminent canopy collisions? Everything!

Today's canopy collisions occur with approach speeds of 50 to 60 mph! Microline slices flesh very well indeed at these speeds. Main parachutes can be jettisoned easily. Reserves open faster and more reliably than before. Human nature is an act of self preservation. A jumpers is more likely to protect himself when colliding with something moving at 50 mph, not spread out and have a parachute slice him to shreds. One more item to observe is that a jumper can fit through the space between adjacent line groups along a ram-air parachute's ribs (chordwise direction). (This may not be true if spanwise cascading is used.)

A better plan to use for imminent ram-air canopy collisions is to tuck up, aim for the space between the lines, swish on through the lines to the other side, cutaway and deploy your reserve. Talk to the other jumper before you cutaway, if time permits.

For those who want to know, "What happens if a jumper doesn't swish on through to the other side, but gets hung up on some lines?", probably the same thing, as if he were to spread his arms and legs. He'll get sliced and burned, but possibly less severe than if his arms and legs were spread out.

To get this plan taught and disseminated throughout the sport parachuting world, you need to tell every jumper you know about this action plan. Talk it up at your DZ. Write to USPA HQ and your Conference Director to get a new and updated recommendation published in PARACHUTIST and the SIM. (The SIM just says avoid canopy collisions, but does not recommend any plan for dealing with an imminent canopy collision).

Originally published in Sport Parachutist's Safety Journal V2, #2 Nov./Dec. 1989.
ęCopyright 1989, 1996 by Jan Meyer. Republished with permission.

Dedicated to enhancing sport parachuting safety by disseminating information about equipment, environments and human factors.

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