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- Jan 7, 2019
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Let's look at some numbers.
6 lb. descent weight, apogee at 7000', which is the top of the waiver, minimum field dimension is 3500', and wind is blowing in that direction; 12" drogue yields 90 fps descent rate.
If you reach apogee directly over the launch pad, and the winds aloft are at 20 mph, it takes 77 seconds to descend. 77 X 90 = 6930 feet of potential drift.
Your drogue descent has put you 3430' beyond the edge of your waiver area. Just sayin'.
OK, I'll play, so let's say you estimate this before launch because you know the potential maximum wind speed, the estimated max altitude and the rate of descent. Since you can calc all this up front, why would you launch? The suggested scenario also doesn't account for weather-cocking due to the lower level winds (likely to exist), hence the distance downrange the rocket goes into the wind, the reduced max altitude from angling over, etc., which can change the dynamics quite a bit as well. Besides, once you are outside of your field dimension, you're all too often screwed. From past (personal) experience, when you fly in high wind conditions, rockets tend to end up in...trees...on roofs...on power lines...in a creek. Been there, done that. Part of flying is knowing when not to fly. Just sayin'.