CanuckInUSA 0 #2 January 3, 2006 It should depend on the ground speed of the aircraft as well as the size of the group ahead of you. Slower ground speed and bigger groups need longer seperation times. Try not to worry about the things you have no control over Quote Share this post Link to post Share on other sites
CrazyL 0 #3 January 3, 2006 Sure, separation should depend on some things. What is your norm? Is there any simple way of determining separation? Quote Share this post Link to post Share on other sites
billvon 2,379 #4 January 3, 2006 >Is there any simple way of determining separation? Always wait at least 7 seconds. If you are flying into strong upper winds, and you have a slow plane, divide the uppers by 2 and use that number of seconds (i.e. 30 kts = 15 seconds.) If you have a fast plane, divide the uppers by 3 and use that (i.e. 30kts = 10 seconds.) If you don't like counting, just look out the door at the ground. When the plane has covered 1000 feet (1/5 mile) exit. If you are following a large group, leave more time. Always put RW out first with a normal (into the wind) jump run. Quote Share this post Link to post Share on other sites
CrazyL 0 #5 January 3, 2006 I agree. Can this formula somehow be expressed to the DZ's and be ultimately used? Quote Share this post Link to post Share on other sites
CrazyL 0 #6 January 3, 2006 True story: As freefly was coming of age and exit order was being figured out freefliers were exiting first before RW. I was in the first out freefly group with an 8 way RW group next. Winds were high from approx. 2-3,000 on up to 13,000 similar direction. A/C flying straight into headwind. Upon opening facing up wind, i hear the whistling sound of bodies in freefall. Next I see someone tracking over the right corner of my canopy, then another and another. I was freaking the shit out! I was basically surrounded by the 8 way breaking off above me and tracking as if their lives depended on it.After much conversation skydivers at the DZ learned something that day. Q: What would be the best scenario for jumprun? If the A/C was flying crosswind in the high winds essentially crabbing each group drifts on it's own line, would this be the best scenario for jumprun. Quote Share this post Link to post Share on other sites
billvon 2,379 #7 January 3, 2006 >Can this formula somehow be expressed to the DZ's and be ultimately used? I tried sending an article in to PARACHUTIST on the issue. They declined to print it. I sent it out to Skydiving magazine, and they said they might use it in the future. Beyond that, not sure how to get the info out there. Quote Share this post Link to post Share on other sites
billvon 2,379 #8 January 3, 2006 >If the A/C was flying crosswind in the high winds essentially crabbing >each group drifts on it's own line, would this be the best scenario for jumprun. Crosswind jump runs can work. However: 1. It is harder to get everyone out on one pass, since groundspeeds are similar to no-wind days 2. It is much harder to spot the load unless you're used to crosswind jump runs, or unless you have a GPS and a good pilot Quote Share this post Link to post Share on other sites
CrazyL 0 #9 January 3, 2006 Well you seem to have tried the most appropriate places to get the word to the masses. You know, 45 degree rule = 3 words = simple/stupid. Can your way of explaining separation be so simplified? I'm trying! Quote Share this post Link to post Share on other sites
JeepDiver 0 #10 January 4, 2006 I like 8 seconds. I've been told 8 seconds, my instructors said 8 seconds. What do I know. Quote Share this post Link to post Share on other sites
LouDiamond 1 #11 January 4, 2006 QuoteCan this formula somehow be expressed to the DZ's and be ultimately used? YES! See the attached excel sheet. Post it by the door of the aircraft by the lights. In order for it to work the pilot must pass the ground speed back to the jumpers while on jump run. It gets no simpler than this and it works."It's just skydiving..additional drama is not required" Some people dream about flying, I live my dream SKYMONKEY PUBLISHING Quote Share this post Link to post Share on other sites
CrazyL 0 #12 January 4, 2006 Quote What do I know. Be observant of the threads concerning separation and you may know even more! I've been an avid jumper for many years,seen changes in skydivers school of thought and SIM over time concerning many parts of skydiving. When on the A/C looking back at the young jumper, what they do for separation has scared the living crap out of me. Having assessed the things about skydivers that scare me most, separation takes top honors. Quote Share this post Link to post Share on other sites
CrazyL 0 #13 January 4, 2006 Argh! security settings won't allow the spreadsheet, can you email it to me please? Quote Share this post Link to post Share on other sites
billvon 2,379 #14 January 4, 2006 Here's the text version of the spreadsheet; hopefully this will work for you. Note that .1 miles is only 500 feet - most groups (2-4 ways) should aim for 1000 feet (.2 miles.) ----------------------------------------------------------- We have GPS, yet you should still spot for clouds and other aircraft yourself !! ASK THE PILOT FOR YOUR JUMP RUN GROUND SPEED !! USE THE TABLE AND BE RESPONSIBLE !! HAVE FUN!! Time between exits should INCLUDE the exit count !!!!! This is all dependent, of course, on the number of groups (Use 0.2 Miles as Default) GROUND SECONDS BETWEEN EXITS SPEED IF DESIRED SEPARATION IS (KNOTS) 0.1 MILES 0.2 MILES 0.3 MILES 125 3 5 8 115 3 5 8 105 3 6 9 95 3 7 10 85 4 7 11 75 4 8 12 65 5 10 14 55 6 11 17 45 7 14 21 35 9 18 26 25 12 25 37 Quote Share this post Link to post Share on other sites
CrazyL 0 #15 January 4, 2006 Taking the first line 125 3 5 8. Is 125 ground speed? 3 5 8 being the .3mi next group .5mi next group .8mi.? Quote Share this post Link to post Share on other sites
billvon 2,379 #16 January 4, 2006 >Is 125 ground speed? 3 5 8 being the .3mi next group .5mi next group .8mi.? No. There are four columns: Groundspeed as shown on the pilot's GPS How long to wait to get .1 mile separation How long to wait to get .2 mile separation How long to wait to get .3 mile separation (.2 miles, or ~1000 feet, is a good normal separation to use) So the first line would tell you to wait 5 seconds for 1000 feet separation. Quote Share this post Link to post Share on other sites
LouDiamond 1 #17 January 4, 2006 E-mail sent with the chart. Be sure you use 0.2 miles as the default.here it is as a picture as well"It's just skydiving..additional drama is not required" Some people dream about flying, I live my dream SKYMONKEY PUBLISHING Quote Share this post Link to post Share on other sites
CrazyL 0 #18 January 4, 2006 125 gps ground speed 3 sec for .1 mi sep, 5 sec for.2mi sep. etc. Quote Share this post Link to post Share on other sites
Lindsey 0 #19 January 4, 2006 Our norm is as follows: We all sardine into Rick's plane (we have leg placement down to an art). We jump. After the plane lands and we pack, we go up and jump again!!!! WEEEEEE! linz-- A conservative is just a liberal who's been mugged. A liberal is just a conservative who's been to jail Quote Share this post Link to post Share on other sites
Miami 0 #20 January 4, 2006 The norm for me is: More wind, wait longer. Less wind, wait less. This past weekend had a jumprun where the pilots gps indicated a steady 17 knts ground speed...I got out somewhere in the neighborhood of a minute and a half after the group before me. The winds at jump run alt are not the only factor...winds all the way down and on the surface play a part in how long I wait as well.Miami Quote Share this post Link to post Share on other sites
CrazyL 0 #21 January 4, 2006 Birman? 1 and half minutes is a very long time between groups. Balloon jump? what A/C? Quote Share this post Link to post Share on other sites
CrazyL 0 #22 January 4, 2006 Thanks, I figured there was a well thought reason for not doing crosswind jumpruns. Quote Share this post Link to post Share on other sites
Miami 0 #23 January 4, 2006 pac750...very high winds all the way down to about 1k'...crawling across the ground and a very significant amount of drift in freefall.Miami Quote Share this post Link to post Share on other sites
CrazyL 0 #24 January 4, 2006 Sounds like a fun 182 DZ! Do you really wait for the plane to land before you start packing? Quote Share this post Link to post Share on other sites
CrazyL 0 #25 January 4, 2006 No kidding. What approx. were the winds aloft? Consitent direction? I'd assume the PAC 750's drag is similar to a Pilatus Porter. Jumped Porter not PAC in similar scenario long ago. Airspeed high, groundspeed sooo slow almost setting still over the ground.So you pretty much waited till 1st group opened and flew out from under your opening area, is that close to right? Quote Share this post Link to post Share on other sites
