chuckakers 370 #26 January 30, 2009 QuoteAnother problem is that the winds aloft forecast is just that, a forecast. It is calculated at various altitudes and is not always accurate. Plus, many drop zones have a small number of preferred jump run directions regardless of winds, perhaps because of landmarks, multi-airplane tracks, or avoidance of congested or unhealthy landing areas. Sometimes a DZ will even eliminate a full section of the compass from consideration for exits. In the civilian world we are always jumping over the same known location, so it makes more sense to identify the forecasted winds, build a paper and pencil spot, and compare actual aircraft track with the proposed jumprun. Then real live humans can make the needed corrections based on all the things computers don't quite grasp. Yeah, yeah - whatever. I get all that. I just want a quick way to let an application do what we already do. Even if the forecast winds aren't accurate, it's still what we us as a starting point now. The application just makes it easier to arrive at the answer. Also, the winds can be determined accurately by the pilot using GPS. Jump run direction doesn't matter as it relates to this thread. All I want is a "the spot" as determined by the best available data, without respect to other factors.Chuck Akers D-10855 Houston, TX Quote Share this post Link to post Share on other sites
el6uapo 0 #27 January 30, 2009 Hmm, is the averaging method so bad? I think there are so many variables involved that the use of a simple and consistent method will produce the most consistent results in an environment with so many uncontrollable variables. Quote Share this post Link to post Share on other sites
chuckakers 370 #28 January 30, 2009 Quote If you design and construct an idiot-proof spotting calculator then someone will just invent a better idiot. I doubt the consistency of even a well designed spotting calculator would improve upon that of an experienced spotter. -Michael That's one of the issues of the day. Many (most?) jumpers hardly know how to spot because we (as an industry) teach them when they have a dozen jumps and then when they get off student status we tell them to watch for a green light, check for traffic, and exit.Chuck Akers D-10855 Houston, TX Quote Share this post Link to post Share on other sites
chuckakers 370 #29 January 30, 2009 Quotehttp://www.digiacom.com/prod_harp/HARP_Home.htm This is what we use at our dz and it works good. Well it took a few replies from the naysayers and complexity gurus, but I finally got my answer - yes!Chuck Akers D-10855 Houston, TX Quote Share this post Link to post Share on other sites
LouDiamond 1 #30 January 30, 2009 QuoteAll I want is a "the spot" as determined by the best available data, without respect to other factors. Point of clarification, this is for ROUND canopies?"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
chuckakers 370 #31 January 30, 2009 Quote Quote All I want is a "the spot" as determined by the best available data, without respect to other factors. Point of clarification, this is for ROUND canopies? You wrote: Part of the formula requires that you know the "K" factor for the canopies being used. In skydiving operations canopies vary drastically in some instances. This "K" factor can be adjusted for but it further complicates and increases the likely hood of some people landing off a lot more than what we see now in civilian operations. I used round, non-steerable canopies in my example to take the canopy variable out of the equation (you know, the way a WDI just accounts for wind drift - not canopy flight variables). Your reply, while quite intelligent, went overboard relative to what I'm talking about. I was referring to a program that can simply say the spot is *approximately* X distance from the target at this heading, all based on some very general wind, exit & deployment, and sport discipline data. I'm not tryin' to knock a flea off dog's butt.Chuck Akers D-10855 Houston, TX Quote Share this post Link to post Share on other sites
councilman24 36 #32 January 30, 2009 Doesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy. Squares just let you be on the wrong side of the airport most of the time.But climbout, exit, opening spot? All different. I'm up for the crepe paper for sport jumpers. I'm old for my age. Terry Urban D-8631 FAA DPRE Quote Share this post Link to post Share on other sites
LouDiamond 1 #33 January 30, 2009 QuoteChuck akers wrote: I was referring to a program that can simply say the spot is *approximately* X distance from the target at this heading, all based on some very general wind, exit & deployment, and sport discipline data. OK, but the way you described it by averaging wind direction and speed will give you what I described. Edit: I never said that this couldn't be done, like I said, it already exists. However, I use this method A LOT for military jumps and I also am very familiar with how most skydiving flight operations operate. Which is why I don't recommend it. Tombuch's comments are another reason why it isn't applicable or feasible for most skydiving operations. His recommendation is pretty good and is what most DZ do in one form or another. Quotecouncilman24 wrote:Doesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy.Quote Actually, it does matter. What I described is for HALO or freefall drops aka skydiving. For HAHOs or standoff drops aka cross country jumps the same applies but the formula is a bit different. Regardless, HALO/HAHO and the calculations for round canopies will all put you in the "wind cone" if jumpers leave the A/C at the correct spot. The spot for a square canopy using the method I described is no where close to where a spot would be for a static line round canopy. FM 3-21.220 explains how winds are calculated for round canopies. Take a look at the PPT shows I posted in the "do bad spots really exist" thread to see how it is done for square canopies. The HALO calculations would be the same even if for some reason you were jumping an old freefall rig with a round main canopy in it, like a paracommander. The only difference is that the "K" factor would be 3 instead of 25 in the formula(D=KAV)."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 councilman24 36 #34 January 30, 2009 I only had a few minutes to look at your ppt and correct me if I'm reading it wrong, but.... Your ram air K values assume the parachute will be pointing at the target the entire descent. Skydivers assume that there will be an equal amount of holding crabing and running. That the skydiver will manuver.For a round canopy the k and a ram air, not taking into account the glide of the ram air would be 25, which essentially represents the time that the canopy is exposed to the wind to be able drift for each 1000'. Freefall is 3, a round main would be 25. Yes, your higher k vaues are correct for someone only running after opening. I'm old for my age. Terry Urban D-8631 FAA DPRE Quote Share this post Link to post Share on other sites LouDiamond 1 #35 January 30, 2009 Quote I only had a few minutes to look at your ppt and correct me if I'm reading it wrong, but.... Your ram air K values assume the parachute will be pointing at the target the entire descent. Skydivers assume that there will be an equal amount of holding crabing and running. That the skydiver will manuver. No, because thats not how it happens in the real world. What you described would be necessary if the safety factor was 0 in the formula. Quote a round main would be 25. How do you figure?"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 chuckakers 370 #36 January 31, 2009 QuoteDoesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy. Exactly, Councilman. It's a concept thing.Chuck Akers D-10855 Houston, TX Quote Share this post Link to post Share on other sites LouDiamond 1 #37 January 31, 2009 QuoteQuoteDoesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy. Exactly, Councilman. It's a concept thing. I'm not an Excel guru by any means but I am fairly certain that there isn't a formula for "concepts". If you want concepts then keep doing what most skydiving operations have been doing for years or invest in a magic 8 ball and ask it where your spot should be. If you want a mathematical derived explanation based on real world conditions(like you asked for) to be expressed in an excel chart then you already have your answer."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 JohnMitchell 14 #38 January 31, 2009 Winds aloft "forecasts" are now more like winds aloft reports, with wind info being downloaded in real time from hundreds of a/c in flight. Even so, I'd never bet my life on the reports. I really don't care about the spot for me too much. I can always fly my canopy to the landing area. I just want somebody to spot for my free bag and cutaway to land in the open, not in the damn trees. Seriously. On really windy days, a spot that puts the wind streamer on target will put your baglock in the woods. Also, big turbine DZ's usually have numerous groups per pass. Only the folks in the middle get the perfect spot. Quote Share this post Link to post Share on other sites pchapman 261 #39 January 31, 2009 Lou: There's clearly still some confusion over what the K value represents and how round vs. square has anything to do with it. And that seems to include those who have checked out the .ppt slides in the other thread, which I'll have a look at soon. The K value represents a units conversion factor (due to mixed units being used in the D=KAV formula) and a descent rate factor to account for how long the parachute is exposed to the wind? But what's with the big round vs. square differences? Quote Share this post Link to post Share on other sites Andy9o8 0 #40 January 31, 2009 Fuck all that. Just fly directly over the peas, wait til it's 45 degrees past the door, then Go. Quote Share this post Link to post Share on other sites chuckakers 370 #41 January 31, 2009 Quote Quote Quote Doesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy. Exactly, Councilman. It's a concept thing. I'm not an Excel guru by any means but I am fairly certain that there isn't a formula for "concepts". If you want concepts then keep doing what most skydiving operations have been doing for years or invest in a magic 8 ball and ask it where your spot should be. If you want a mathematical derived explanation based on real world conditions(like you asked for) to be expressed in an excel chart then you already have your answer. There's one at every DZ. I guess Lou is the one at his.Chuck Akers D-10855 Houston, TX Quote Share this post Link to post Share on other sites LouDiamond 1 #42 January 31, 2009 Quote Quote Quote Quote Doesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy. Exactly, Councilman. It's a concept thing. I'm not an Excel guru by any means but I am fairly certain that there isn't a formula for "concepts". If you want concepts then keep doing what most skydiving operations have been doing for years or invest in a magic 8 ball and ask it where your spot should be. If you want a mathematical derived explanation based on real world conditions(like you asked for) to be expressed in an excel chart then you already have your answer. There's one at every DZ. I guess Lou is the one at his. If you took offense to my statement ,you took it the wrong way. Despite what you may think, I was not trying to be a dick when I wrote the above statement.I was simply being direct in answering your question, which was asking for a way to use a mathematical formula to determine the spot. You then later post and contradict yourself by saying that it's a concept thing. The simple answer is it can't be both without being half assed one way or the other. Do you want a concept or do you want an excel sheet that uses math to average the winds? Unless of course I misunderstood your post and you meant that I was the good looking one at my DZ? You can use which ever method you choose. However as I stated , I don't recommend using the described military excel/math formula for civilian skydiving for a plethora of reasons. Looking at the formulas, I think you could probably accomplish close to what you want by just setting up an excel sheet that averages the winds from exit altitude to 1000 feet and the wind velocities. Plug those sums into the canopy drift formula only D= 25(constant) x 3(opening altitude) x averaged wind velocity= XXXX kilometers on a XXX degree magnetic heading (averaged wind direction) . This eliminates the freefall drift calculations which would put you further away from the DZ. This method would put you in the ball park. However, if the winds at altitude are railing you could end up with people opening up downwind a good deal and or directly over the DZ with lots of altitude, creating traffic issues. My gut feeling is that using this method will always create a short spot that will need to be extended further up wind. But that's where the "concept" method could be applied and the 2nd load could be adjusted further up wind the guesstimated needed amount so that everyone landed on . This would also probably ensure cutaways landed on/around the DZ as well (Hmmm, this sounds very familiar). My guess is that using this method will probably put you in an aircraft flight pattern close to what most DZ already routinely fly as it is. This is just my SWAG, so no guarantees, but give it a try and see if it does what you are looking for."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 kallend 1,623 #43 January 31, 2009 QuoteI've been thinking about doing something like that for a while, just haven't had the time or motivation. I'll bet Kallend could modify his separation program to do what you want quite easily. For a short time we had an online version that did exactly that. Took it offline because the 3-d graphics package we used became unavailable. It's a pretty straightforward physics problem. Not sure if it would be really practical in real time but it might be useful before the wind dummy load.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites Andy9o8 0 #44 January 31, 2009 Quotethe wind dummy load. Back In The Day, we used to refer to that as the first load of S/L students. Quote Share this post Link to post Share on other sites hackish 8 #45 February 1, 2009 A lot of the older jumpers grumble about the light watchers on a load... well back in my day we.... This really depends on what sort of DZ you're at. At a small cessna dropzone you must have and use your spotting skills. Some of our pilots are good at putting us up the right place but others are good only at getting us to 10,500. At the larger DZ's on the larger planes I can understand how the skill of spotting is lost, but many of us still know how and regularly practice spotting. I snicker to myself reading the ideas here. It's like a business student running fomulas versus an old businessman who just knows from experience what to sell a product for. The engineering types can build a complex system that's difficult to use and accomplishes pretty much the same thing as an experienced spotter. -Michael Quote Share this post Link to post Share on other sites BIGUN 1,053 #46 February 1, 2009 Spotting .PPT Your two word documents are just two threads above this .ppt.Nobody has time to listen; because they're desperately chasing the need of being heard. Quote Share this post Link to post Share on other sites chuckakers 370 #47 February 1, 2009 Quote Quote Quote Quote Quote Doesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy. Exactly, Councilman. It's a concept thing. I'm not an Excel guru by any means but I am fairly certain that there isn't a formula for "concepts". If you want concepts then keep doing what most skydiving operations have been doing for years or invest in a magic 8 ball and ask it where your spot should be. If you want a mathematical derived explanation based on real world conditions(like you asked for) to be expressed in an excel chart then you already have your answer. There's one at every DZ. I guess Lou is the one at his. If you took offense to my statement ,you took it the wrong way. Despite what you may think, I was not trying to be a dick when I wrote the above statement.I was simply being direct in answering your question, which was asking for a way to use a mathematical formula to determine the spot. You then later post and contradict yourself by saying that it's a concept thing. The simple answer is it can't be both without being half assed one way or the other. Do you want a concept or do you want an excel sheet that uses math to average the winds? Unless of course I misunderstood your post and you meant that I was the good looking one at my DZ? You can use which ever method you choose. However as I stated , I don't recommend using the described military excel/math formula for civilian skydiving for a plethora of reasons. Looking at the formulas, I think you could probably accomplish close to what you want by just setting up an excel sheet that averages the winds from exit altitude to 1000 feet and the wind velocities. Plug those sums into the canopy drift formula only D= 25(constant) x 3(opening altitude) x averaged wind velocity= XXXX kilometers on a XXX degree magnetic heading (averaged wind direction) . This eliminates the freefall drift calculations which would put you further away from the DZ. This method would put you in the ball park. However, if the winds at altitude are railing you could end up with people opening up downwind a good deal and or directly over the DZ with lots of altitude, creating traffic issues. My gut feeling is that using this method will always create a short spot that will need to be extended further up wind. But that's where the "concept" method could be applied and the 2nd load could be adjusted further up wind the guesstimated needed amount so that everyone landed on . This would also probably ensure cutaways landed on/around the DZ as well (Hmmm, this sounds very familiar). My guess is that using this method will probably put you in an aircraft flight pattern close to what most DZ already routinely fly as it is. This is just my SWAG, so no guarantees, but give it a try and see if it does what you are looking for. You still don't get it. My whole point is and has been that your replies are way over complicated. Why is it so tough to get you to understand that all I was looking for was a simple spot calculator? All the crap about different canopies and K, X, and whatever factors are irrelevant. As I said, I'm not trying to knock a flea off a dog's butt. Re-read Councilman's post. He hit it right on the head. I'm glad you're good at math and formulas, but demonstrating you know what you're talking about still hasn't produced anything. I hope you don't act like this at your DZ. If you do, your are the one I was referring to. If you choose to reply, please just type "blah, blah, blah". It will just as relevent as anything else you may type.Chuck Akers D-10855 Houston, TX Quote Share this post Link to post Share on other sites BIGUN 1,053 #48 February 1, 2009 QuoteIt's like a business student running fomulas versus an old businessman who just knows from experience what to sell a product for. But, let's not forget, the older experienced businessman once had to do the formulas on paper, before his experience allowed him to do them in his head. Several former Jumpmasters and Pathfinders in this thread... we started out doing the the formulas on paper long before we had the experience or confidence to do them in our head.Nobody has time to listen; because they're desperately chasing the need of being heard. Quote Share this post Link to post Share on other sites BIGUN 1,053 #49 February 1, 2009 QuoteWhy is it so tough to get you to understand that all I was looking for was a simple spot calculator? Simple != Spot Calculator. If you want simple - go on Green and takes your chances.Nobody has time to listen; because they're desperately chasing the need of being heard. Quote Share this post Link to post Share on other sites LouDiamond 1 #50 February 1, 2009 QuoteYou still don't get it. My whole point is and has been that your replies are way over complicated. Why is it so tough to get you to understand that all I was looking for was a simple spot calculator? All the crap about different canopies and K, X, and whatever factors are irrelevant. Oh, I get it. But I was attempting to explain to you and anyone else who is interested in how to go about building a simple spot calculator. In order to do that you do need a modicum of understanding of how to do it. Otherwise you'd be better off asking the magic 8 ball where the spot should be each day. Here, I'll make it as easy as possible, do the following: D=KAV. You can do that with a pencil, scrap of paper and wind data. If you want to go high tech, put the formulas in an excel sheet. QuoteI hope you don't act like this at your DZ. If you do, your are the one I was referring to If you mean the one who takes the time to try and help and educate people and answer their questions then yes, that is me. I have provided you with an answer to your question on how to obtain what you want. Do you also want me to build you an excel sheet that does what I explained?"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 Prev 1 2 3 4 Next Page 2 of 4 Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. Insert image from URL × Desktop Tablet Phone Submit Reply 0 Go To Topic Listing
councilman24 36 #34 January 30, 2009 I only had a few minutes to look at your ppt and correct me if I'm reading it wrong, but.... Your ram air K values assume the parachute will be pointing at the target the entire descent. Skydivers assume that there will be an equal amount of holding crabing and running. That the skydiver will manuver.For a round canopy the k and a ram air, not taking into account the glide of the ram air would be 25, which essentially represents the time that the canopy is exposed to the wind to be able drift for each 1000'. Freefall is 3, a round main would be 25. Yes, your higher k vaues are correct for someone only running after opening. I'm old for my age. Terry Urban D-8631 FAA DPRE Quote Share this post Link to post Share on other sites
LouDiamond 1 #35 January 30, 2009 Quote I only had a few minutes to look at your ppt and correct me if I'm reading it wrong, but.... Your ram air K values assume the parachute will be pointing at the target the entire descent. Skydivers assume that there will be an equal amount of holding crabing and running. That the skydiver will manuver. No, because thats not how it happens in the real world. What you described would be necessary if the safety factor was 0 in the formula. Quote a round main would be 25. How do you figure?"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
chuckakers 370 #36 January 31, 2009 QuoteDoesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy. Exactly, Councilman. It's a concept thing.Chuck Akers D-10855 Houston, TX Quote Share this post Link to post Share on other sites
LouDiamond 1 #37 January 31, 2009 QuoteQuoteDoesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy. Exactly, Councilman. It's a concept thing. I'm not an Excel guru by any means but I am fairly certain that there isn't a formula for "concepts". If you want concepts then keep doing what most skydiving operations have been doing for years or invest in a magic 8 ball and ask it where your spot should be. If you want a mathematical derived explanation based on real world conditions(like you asked for) to be expressed in an excel chart then you already have your answer."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
JohnMitchell 14 #38 January 31, 2009 Winds aloft "forecasts" are now more like winds aloft reports, with wind info being downloaded in real time from hundreds of a/c in flight. Even so, I'd never bet my life on the reports. I really don't care about the spot for me too much. I can always fly my canopy to the landing area. I just want somebody to spot for my free bag and cutaway to land in the open, not in the damn trees. Seriously. On really windy days, a spot that puts the wind streamer on target will put your baglock in the woods. Also, big turbine DZ's usually have numerous groups per pass. Only the folks in the middle get the perfect spot. Quote Share this post Link to post Share on other sites
pchapman 261 #39 January 31, 2009 Lou: There's clearly still some confusion over what the K value represents and how round vs. square has anything to do with it. And that seems to include those who have checked out the .ppt slides in the other thread, which I'll have a look at soon. The K value represents a units conversion factor (due to mixed units being used in the D=KAV formula) and a descent rate factor to account for how long the parachute is exposed to the wind? But what's with the big round vs. square differences? Quote Share this post Link to post Share on other sites
Andy9o8 0 #40 January 31, 2009 Fuck all that. Just fly directly over the peas, wait til it's 45 degrees past the door, then Go. Quote Share this post Link to post Share on other sites
chuckakers 370 #41 January 31, 2009 Quote Quote Quote Doesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy. Exactly, Councilman. It's a concept thing. I'm not an Excel guru by any means but I am fairly certain that there isn't a formula for "concepts". If you want concepts then keep doing what most skydiving operations have been doing for years or invest in a magic 8 ball and ask it where your spot should be. If you want a mathematical derived explanation based on real world conditions(like you asked for) to be expressed in an excel chart then you already have your answer. There's one at every DZ. I guess Lou is the one at his.Chuck Akers D-10855 Houston, TX Quote Share this post Link to post Share on other sites
LouDiamond 1 #42 January 31, 2009 Quote Quote Quote Quote Doesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy. Exactly, Councilman. It's a concept thing. I'm not an Excel guru by any means but I am fairly certain that there isn't a formula for "concepts". If you want concepts then keep doing what most skydiving operations have been doing for years or invest in a magic 8 ball and ask it where your spot should be. If you want a mathematical derived explanation based on real world conditions(like you asked for) to be expressed in an excel chart then you already have your answer. There's one at every DZ. I guess Lou is the one at his. If you took offense to my statement ,you took it the wrong way. Despite what you may think, I was not trying to be a dick when I wrote the above statement.I was simply being direct in answering your question, which was asking for a way to use a mathematical formula to determine the spot. You then later post and contradict yourself by saying that it's a concept thing. The simple answer is it can't be both without being half assed one way or the other. Do you want a concept or do you want an excel sheet that uses math to average the winds? Unless of course I misunderstood your post and you meant that I was the good looking one at my DZ? You can use which ever method you choose. However as I stated , I don't recommend using the described military excel/math formula for civilian skydiving for a plethora of reasons. Looking at the formulas, I think you could probably accomplish close to what you want by just setting up an excel sheet that averages the winds from exit altitude to 1000 feet and the wind velocities. Plug those sums into the canopy drift formula only D= 25(constant) x 3(opening altitude) x averaged wind velocity= XXXX kilometers on a XXX degree magnetic heading (averaged wind direction) . This eliminates the freefall drift calculations which would put you further away from the DZ. This method would put you in the ball park. However, if the winds at altitude are railing you could end up with people opening up downwind a good deal and or directly over the DZ with lots of altitude, creating traffic issues. My gut feeling is that using this method will always create a short spot that will need to be extended further up wind. But that's where the "concept" method could be applied and the 2nd load could be adjusted further up wind the guesstimated needed amount so that everyone landed on . This would also probably ensure cutaways landed on/around the DZ as well (Hmmm, this sounds very familiar). My guess is that using this method will probably put you in an aircraft flight pattern close to what most DZ already routinely fly as it is. This is just my SWAG, so no guarantees, but give it a try and see if it does what you are looking for."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
kallend 1,623 #43 January 31, 2009 QuoteI've been thinking about doing something like that for a while, just haven't had the time or motivation. I'll bet Kallend could modify his separation program to do what you want quite easily. For a short time we had an online version that did exactly that. Took it offline because the 3-d graphics package we used became unavailable. It's a pretty straightforward physics problem. Not sure if it would be really practical in real time but it might be useful before the wind dummy load.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
Andy9o8 0 #44 January 31, 2009 Quotethe wind dummy load. Back In The Day, we used to refer to that as the first load of S/L students. Quote Share this post Link to post Share on other sites
hackish 8 #45 February 1, 2009 A lot of the older jumpers grumble about the light watchers on a load... well back in my day we.... This really depends on what sort of DZ you're at. At a small cessna dropzone you must have and use your spotting skills. Some of our pilots are good at putting us up the right place but others are good only at getting us to 10,500. At the larger DZ's on the larger planes I can understand how the skill of spotting is lost, but many of us still know how and regularly practice spotting. I snicker to myself reading the ideas here. It's like a business student running fomulas versus an old businessman who just knows from experience what to sell a product for. The engineering types can build a complex system that's difficult to use and accomplishes pretty much the same thing as an experienced spotter. -Michael Quote Share this post Link to post Share on other sites
BIGUN 1,053 #46 February 1, 2009 Spotting .PPT Your two word documents are just two threads above this .ppt.Nobody has time to listen; because they're desperately chasing the need of being heard. Quote Share this post Link to post Share on other sites
chuckakers 370 #47 February 1, 2009 Quote Quote Quote Quote Quote Doesn't matter. We're not doing stand off drops and flying one direction to the landing zone. We want the center of the cone of controllability (or what ever you want to call it). The spot for a square IS the spot for an unmodified round canopy. Exactly, Councilman. It's a concept thing. I'm not an Excel guru by any means but I am fairly certain that there isn't a formula for "concepts". If you want concepts then keep doing what most skydiving operations have been doing for years or invest in a magic 8 ball and ask it where your spot should be. If you want a mathematical derived explanation based on real world conditions(like you asked for) to be expressed in an excel chart then you already have your answer. There's one at every DZ. I guess Lou is the one at his. If you took offense to my statement ,you took it the wrong way. Despite what you may think, I was not trying to be a dick when I wrote the above statement.I was simply being direct in answering your question, which was asking for a way to use a mathematical formula to determine the spot. You then later post and contradict yourself by saying that it's a concept thing. The simple answer is it can't be both without being half assed one way or the other. Do you want a concept or do you want an excel sheet that uses math to average the winds? Unless of course I misunderstood your post and you meant that I was the good looking one at my DZ? You can use which ever method you choose. However as I stated , I don't recommend using the described military excel/math formula for civilian skydiving for a plethora of reasons. Looking at the formulas, I think you could probably accomplish close to what you want by just setting up an excel sheet that averages the winds from exit altitude to 1000 feet and the wind velocities. Plug those sums into the canopy drift formula only D= 25(constant) x 3(opening altitude) x averaged wind velocity= XXXX kilometers on a XXX degree magnetic heading (averaged wind direction) . This eliminates the freefall drift calculations which would put you further away from the DZ. This method would put you in the ball park. However, if the winds at altitude are railing you could end up with people opening up downwind a good deal and or directly over the DZ with lots of altitude, creating traffic issues. My gut feeling is that using this method will always create a short spot that will need to be extended further up wind. But that's where the "concept" method could be applied and the 2nd load could be adjusted further up wind the guesstimated needed amount so that everyone landed on . This would also probably ensure cutaways landed on/around the DZ as well (Hmmm, this sounds very familiar). My guess is that using this method will probably put you in an aircraft flight pattern close to what most DZ already routinely fly as it is. This is just my SWAG, so no guarantees, but give it a try and see if it does what you are looking for. You still don't get it. My whole point is and has been that your replies are way over complicated. Why is it so tough to get you to understand that all I was looking for was a simple spot calculator? All the crap about different canopies and K, X, and whatever factors are irrelevant. As I said, I'm not trying to knock a flea off a dog's butt. Re-read Councilman's post. He hit it right on the head. I'm glad you're good at math and formulas, but demonstrating you know what you're talking about still hasn't produced anything. I hope you don't act like this at your DZ. If you do, your are the one I was referring to. If you choose to reply, please just type "blah, blah, blah". It will just as relevent as anything else you may type.Chuck Akers D-10855 Houston, TX Quote Share this post Link to post Share on other sites
BIGUN 1,053 #48 February 1, 2009 QuoteIt's like a business student running fomulas versus an old businessman who just knows from experience what to sell a product for. But, let's not forget, the older experienced businessman once had to do the formulas on paper, before his experience allowed him to do them in his head. Several former Jumpmasters and Pathfinders in this thread... we started out doing the the formulas on paper long before we had the experience or confidence to do them in our head.Nobody has time to listen; because they're desperately chasing the need of being heard. Quote Share this post Link to post Share on other sites
BIGUN 1,053 #49 February 1, 2009 QuoteWhy is it so tough to get you to understand that all I was looking for was a simple spot calculator? Simple != Spot Calculator. If you want simple - go on Green and takes your chances.Nobody has time to listen; because they're desperately chasing the need of being heard. Quote Share this post Link to post Share on other sites
LouDiamond 1 #50 February 1, 2009 QuoteYou still don't get it. My whole point is and has been that your replies are way over complicated. Why is it so tough to get you to understand that all I was looking for was a simple spot calculator? All the crap about different canopies and K, X, and whatever factors are irrelevant. Oh, I get it. But I was attempting to explain to you and anyone else who is interested in how to go about building a simple spot calculator. In order to do that you do need a modicum of understanding of how to do it. Otherwise you'd be better off asking the magic 8 ball where the spot should be each day. Here, I'll make it as easy as possible, do the following: D=KAV. You can do that with a pencil, scrap of paper and wind data. If you want to go high tech, put the formulas in an excel sheet. QuoteI hope you don't act like this at your DZ. If you do, your are the one I was referring to If you mean the one who takes the time to try and help and educate people and answer their questions then yes, that is me. I have provided you with an answer to your question on how to obtain what you want. Do you also want me to build you an excel sheet that does what I explained?"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
