Avoiding Canopy Collisions - Breakoff Separation
As skydiving continues to progress—with jumpers now enjoying a wide variety of disciplines and piloting faster canopies—it has become more challenging to find clear airspace at deployment time. Since 1999, 11 jumpers have died in canopy collisions. Additionally, there were many instances of collisions that resulted in injuries or cutaways, although the exact number is unknown.
Two plans can help you avoid collisions: a plan for separation between yourself and the other jumpers in your group and a plan for separation between your group and any other groups on the airplane. Time and altitude are critical factors for both types of separation. This article will address separation from the other jumpers in your group, and next month’s “Safety Check” will address separation between groups.
Whether your group is a 2-way or a 400-way, each jumper needs to gain enough separation from the other jumpers in the formation to deploy in clear airspace. You would think that smaller groups would have an advantage at finding clear airspace, since there are fewer bodies in the air. However, most of the fatal deployment collisions occurred among groups of four skydivers or fewer. So don’t get complacent about group separation just because you are jumping with only two or three friends. It takes only two jumpers to create a canopy collision.
The plan for every skydive should include the altitudes for breakoff and deployment, as well as a plan for the canopy descent from opening to landing. For groups of five or fewer, Skydiver’s Information Manual Section 6-1 recommends a breakoff altitude at least 1,500 feet higher than the highest planned deployment altitude. For groups of six or more, the SIM recommends a breakoff altitude at least 2,000 feet higher than the highest planned deployment altitude. You should consider increases to the recommended altitudes for any of these factors: faster-falling groups (generally freefly groups), slower-opening or faster-flying canopies, jumpers with low experience levels, jumps with toys or props and jumps over unfamiliar areas.
Stay on top of your altitude during freefall with frequent altitude checks, and break off at the altitude you planned. In general, you need a minimum of 300 feet of horizontal distance from another canopy to allow enough time to recognize a potential head-on collision and react to avoid it. It is sometimes tempting to keep the jump going and squeeze in just one more point, but stick to your planned breakoff altitude or you might regret it! Occasionally, it may be necessary to break off sooner and deploy higher than planned. If the spot is far from the airport, deploying higher than planned (if it is safe to do so) can help you make it back to the landing area and avoid having to land off the drop zone.
Horizontal separation from other jumpers is critical for deploying safely, so solid tracking skills are essential. Although you began learning to track properly when you trained for the A license, you should continue to work on refining your tracking skills on every skydive. Also, never factor in vertical separation when deciding on the adequate distance from another jumper. If you deploy directly below another jumper, he might end up freefalling into you. Or if one brake on the higher jumper’s canopy releases during deployment, he could spiral into you from above. Or if the higher jumper has a malfunction and cuts away, his now-freefalling body could drop onto you.
Gaining separation between jumpers within a group is an important part of avoiding deployment collisions. Gaining separation between different groups is the other part of the puzzle. Fast canopies and a wide variety of disciplines can make designing a good separation plan challenging, especially in larger airplanes with multiple groups. Next month, “Safety Check” will address group separation.