johnfallo

*Miss Melissa, I also try to teach my students how to gather the necessary information and the education to think for themselves - to use the winds forecast to make an educated guess about ground speed of the aircraft and therefore separation. I feel this is a good exercise. However, I feel it is inadequate in practice due to the many factors which can change the actual ground speed of the aircraft such as incorrect forecast, winds changing over the course of the day, jump run being flown not directly into the upper winds. Unfortunately many jumpers are not interested in doing math when they arrive at the dropzone, especially some of the more experienced jumpers. With 23 people on an otter load, I do not want those I care for relying on someone's best guess of conditions that may have changed, much less the jumpers that don't bother. The key is getting ground speed from the pilot after the cut every load. This information is right in front of him on his GPS. It is the only accurate way which takes into account any changing conditions or off heading jump runs. You stated it very well in your Blog post, "Seconds Count." That statement couldn't be more true. As in my first example, the 2 extra seconds called for could have made the difference between having some fun and two jumpers having a very bad day. Most jumpers will do what is asked of them to insure safety. The rest will comply if it is a matter of policy with consequences. Without a policy and everyone on board we will just be waiting for the next incident. Last weekend we had a 23 knot ground speed at 14,000 feet. There were 20 jumpers on the otter, multiple groups and each group gave 30 seconds with no go-around. No one had any trouble making it back to the dropzone.

To the 45 degree rule people: we all probably prefer to employ the methods we learned first and are most familiar with. That doesn't always make them the most reliable methods. The article ( http://www.dropzone.com/safety/Exit/Exit_Separation_Revisited_628.html ) which I linked to near the end of my article goes into far more technical detail than I wanted to get into as to why the 45 degree rule is not a reliable method. I wanted to keep things simple and accurate for all levels of jumpers.