obelixtim 150 #26 September 10, 2017 evh *** A: From ATC obtain a list of wind velocities and bearings for every 1000 feet of altitude to your planned exit altitude. You'd be surprised by the sometimes quite wide variations in wind speeds and headings at different levels. B: On a map plot the mean wind direction, using the bearings given from ATC for every 1000 feet. C: For every 30 knots of wind, allow 1 mile of ground travel per 1000 feet, upwind of the DZ. (With a tailwind + canopy speed you should travel 1 mile) and work out your average wind speed from exit altitude to ground level. D: On your map you can now calculate your exit point upwind from the DZ. So you should allow 1 minute of canopy flight per 1000 feet, and 1 mile of travel per minute if you have an average wind speed of 30 knots... I think this was the plan. One big misstake was made: the weather data was incorrect. During the day the winds were pretty strong, these values were used to calculate the exit point. But we jumped just before sunset, when the winds became almost zero That's why I said, plan your jump, jump your plan. If conditions change, new plan. Its not unusual for winds to die down in the evening, in fact they can often change 180 degrees, as the land cools, especially if there is a large body of water nearby.... Something your "planners" didn't take into account.My computer beat me at chess, It was no match for me at kickboxing.... Quote Share this post Link to post Share on other sites
Baksteen 84 #27 September 11, 2017 obelixtim ******That was a crap effort whoever determined the spot.....but the 3 kms illustrates my point perfectly. Boy, was it ever... Incidentally, the experienced people with their handcherchief-sized mains all landed 7-9 km off. I'm not disagreeing with you though; 3.5Kft is the best exit altitude for SL. Did anyone actually know how to calculate the exit point for a high altitude opening/cross country jump? It takes a little bit more than guess work.... I would have let them walk home.... Sigh... No, it was one big zoo dive; three caravans full of Mad Skillz irresponsible Skygods who did and do not know wat they were doing and should have talked to their instructor's instructors.Of course there were lessons learned.. that doesn't mean it isn't a good bonfire story, especially as it happened at a boogie almost a decade ago."That formation-stuff in freefall is just fun and games but with an open parachute it's starting to sound like, you know, an extreme sport." ~mom Quote Share this post Link to post Share on other sites
