Re: PC in tow... for real this time

[billbooth 10]

Pilotdave;
What happened to you is getting more and more common. As a matter of fact, last Sunday, a jumper came up to me, said that he was having "pilot chute hesitations" on his Vector, and asked me to have a look. His problem, it turned out, was the same one I've seen countless times before...His pilot chute was made by "God knows who", and made incorrectly. It seems that dozens of people, who have little idea what they are doing, are making and selling hand deploy pilot chutes. I don't know about you, but one of the the scariest malfunctions I can think of, is a streamered main pilot chute that has enough drag to open your main container, but doesn't have enough drag to lift out the bag. What do you do? If you just lie there and wait, the ground may "rise up to smite thee". If you pull your reserve, your main is going to simultaneously deploy, and main /reserve entanglements are rarely much fun either. What to do...Easy, don't jump an incorrectly manufactured or adjusted pilot chute. So how can I tell if my hand deploy pilot chute is OK. First, some basic definitions. 1. Apex - The center of the fabric part of your pilot chute. 2. Skirt - Where the mesh and fabric meet. 3. Base - The center of the mesh part of your pilot chute. 4. Centerline - One or two pieces of tape, of fixed length, that lead from the apex to the base. 5. Bridle - A piece of tape, doubled in the case of a collapsable pilot chute, leading from the base to the deployment bag. 6. Kill line - A single piece of line, on a collapsable pilot chute only, that runs from the apex, through the center of the pilot chute, and down through the bridle to the pilot chute attachment point at the bag, or to the apex of the canopy. 7. Support tape - 4 pieces of thin tape, sewn to the mesh, leading from the base to the skirt. 8. Bias - Simply put, the direction the mesh stretches the most (a diagonal line, at 45 degrees to the little squares that make up most mesh used in hand deploy pilot chutes). Sorry for all that defining, but if you don't understand those terms, you won't understand what comes next. OK, now the easy part. If you want your pilot chute to always function properly, simply make sure, in the inflated state, that no part of the skirt is above the apex. How do I check that? First cock you pilot chute like you would during packing. Now hold your pilot chute upside down by the bridle at the base. Simultaneously pull downward on the apex (handle) and each support tape where it touches the skirt. The apex should be equal to, preferable slightly "below", but never "above" the skirt. (Please remember, the terms "above" and "below" refer only to the "upside down" pilot chute you are holding in your hands.) Now look how your support tapes are sewn to the mesh. If they are sewn "on the bias" your pilot chute is properly constructed. If they are not sewn on the bias it means that the mesh halfway between each support tape is on the bias and will stretch more than enough to allow the skirt to get way "below" the apex. Try it. This construction error might not let your pilot chute fully inflate, or in extreme cases, inflate at all. If your pilot chute is "borderline" when it is new, then things will get worse and worse as it ages.