cvfd1399 0 #1 October 18, 2004 (Ok I did a search, and did not come up with the numbers I wanted. The base guys had a excel on a website, but the link was bad) I have a <100 jump# F-111 36" non-collapse pilot chute. I am looking for drag in pounds for speeds including 100-200mph in 20 mph increments Ie 100mph=80lbs 120mph=90lbs ECT. I realize all the variables , and just need numbers to see what kind of loads that "could" be subjected to it at blank speeds. Thanks in advance Quote Share this post Link to post Share on other sites BartsDaddy 4 #2 October 18, 2004 Get you a big fish scale and a fast car. Attache the pilot chute to the scale and hold on to the other end of the scale and drive at the speeds you want then look at the scale reading and you have your answer--------------------------------------------------------------------------------------------------------- Handguns are only used to fight your way to a good rifle Quote Share this post Link to post Share on other sites diablopilot 2 #3 October 18, 2004 DUDE!!! You just CAN'T give someone advice like that!!!!!!!!!!!!!! You TOTALY forgot to tell them to get VIDEO!!---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites cvfd1399 0 #4 October 18, 2004 I read that on a base forum too. There was something about a dislocated shoulder somewhere in that post also.lol Quote Share this post Link to post Share on other sites MWGemini 0 #5 October 18, 2004 If you want to rig a setup like this, my suggestion is to do it from the back of a pickup truck, mount the scale to something firmly attached to the truck, and have somebody in the bed monitor the scale (and/or film it). Two way radios would aid in communication. Then you can have somebody in the passenger seat writing down the speed and forces. Should work. I'd be interested to read your results. Mike Quote Share this post Link to post Share on other sites sundevil777 93 #6 October 18, 2004 Or just get somebody with Dan Poynter's manual to look it up. It does at least have some data points as a starter for the curious.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites mjosparky 3 #7 October 18, 2004 QuoteIf you want to rig a setup like this, my suggestion is to do it from the back of a pickup truck, mount the scale to something firmly attached to the truck, and have somebody in the bed monitor the scale (and/or film it). Two way radios would aid in communication. Then you can have somebody in the passenger seat writing down the speed and forces. Should work. I'd be interested to read your results. Mike I would like to be there and watch when this P/U truck is driven at 100 to 200 mph with a PC in tow. The average hand deploy PC, at terminal, arould 120 +/- will produce over 100 pounds of drag. I not as detailed at you asked for but that is all I have tested to. SparkyMy idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites gus 1 #8 October 18, 2004 QuoteThe base guys had a excel on a website, but the link was bad Try this. If it doesn't work I can email it to you. GusOutpatientsOnline.com Quote Share this post Link to post Share on other sites billbooth 10 #9 October 18, 2004 I actually did the "pick-up truck" test about 30 years ago. The results are kinda' fuzzy, but did work out to about one pound, per mile per hour, on a 36" pilot chute. The drag on smaller sizes with be in proportion to the relative area of the pilot chute. For instance a 36" pilot chute has an area of 1017.36 square inches. A 27" pilot has an area of 572.265 square inches, or just more than half the area (56.25%) of a 36" chute. (Of course, these are "flat" areas, not inflated areas, but will do for the purpose of example.) Anyway, half the area equals half the drag. So if a 36"er pulls 120 lbs at 120 mph, the a 27"er should pull 67.5 lbs. at 120 mph. Quote Share this post Link to post Share on other sites cvfd1399 0 #10 October 18, 2004 Well the data in his book that I could find only had it at 35 mph. The other data was in a wind tunnel at 120 mph which at this point is the only number I have. Quote Share this post Link to post Share on other sites cvfd1399 0 #11 October 18, 2004 Thanks bill that is the ball park figures I was looking for. The reason for the season was to see how much pressure is applied to the bridle and pin at the attachment point. Quote Share this post Link to post Share on other sites pilotdave 0 #12 October 18, 2004 Keep in mind that real world factors complicate things a lot. I mean, you can probably get a decent ballpark figure which I'm sure is all you need, but actual forces get very tricky. I mean, just because the PC develops X pounds of drag doesn't mean that X pounds of force gets transmitted to the pin. It's also a dynamic situation vs. static... assuming you don't have a PC in tow. But if you were looking for a realistic number, you'd need to know a lot more than just the drag that the PC can generate. Dave Quote Share this post Link to post Share on other sites mjosparky 3 #13 October 18, 2004 QuoteI actually did the "pick-up truck" test about 30 years ago. The results are kinda' fuzzy, but did work out to about one pound, per mile per hour, on a 36" pilot chute. The drag on smaller sizes with be in proportion to the relative area of the pilot chute. For instance a 36" pilot chute has an area of 1017.36 square inches. A 27" pilot has an area of 572.265 square inches, or just more than half the area (56.25%) of a 36" chute. (Of course, these are "flat" areas, not inflated areas, but will do for the purpose of example.) Anyway, half the area equals half the drag. So if a 36"er pulls 120 lbs at 120 mph, the a 27"er should pull 67.5 lbs. at 120 mph. Bill, I take it you were using a PC made of a lopo type material? With a 27" ZP PC, I maxed out a 100 pound scale at just over 95 mph. SparkyMy idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites billbooth 10 #14 October 18, 2004 Back then it probably was very porous fabric. ZP fabric would obviously pull more. Quote Share this post Link to post Share on other sites cvfd1399 0 #15 October 18, 2004 You would know why I am asking this sparky. My MT1-XXagve me 2 floating ripcords(both I reached and found) this weekend so I had it changed to BOC. My rigger sewed a spandex pouch on the bottom of the rig, a 3 inch piece of velcro that leads from the mouth of the pouch to under the flap that the bridle goes on. Then we installed a approx7' bridle and a 36'' pilot chute. I have yet to jump it. You think the 36'' is good enough. I have already jumped the DZ's MT1-XX that has been converted this way, and I love it. A little more about the floting ripcords. The main deployment ripcord fits outboard on the right MLW. It fits sung in the pocket, but on 2 consecutive RW jumps it came out in my track near pull time. I just looked over at it and deployed like normal. Quote Share this post Link to post Share on other sites mjosparky 3 #16 October 18, 2004 PM sent. SparkyMy idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites 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. 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BartsDaddy 4 #2 October 18, 2004 Get you a big fish scale and a fast car. Attache the pilot chute to the scale and hold on to the other end of the scale and drive at the speeds you want then look at the scale reading and you have your answer--------------------------------------------------------------------------------------------------------- Handguns are only used to fight your way to a good rifle Quote Share this post Link to post Share on other sites
diablopilot 2 #3 October 18, 2004 DUDE!!! You just CAN'T give someone advice like that!!!!!!!!!!!!!! You TOTALY forgot to tell them to get VIDEO!!---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
cvfd1399 0 #4 October 18, 2004 I read that on a base forum too. There was something about a dislocated shoulder somewhere in that post also.lol Quote Share this post Link to post Share on other sites
MWGemini 0 #5 October 18, 2004 If you want to rig a setup like this, my suggestion is to do it from the back of a pickup truck, mount the scale to something firmly attached to the truck, and have somebody in the bed monitor the scale (and/or film it). Two way radios would aid in communication. Then you can have somebody in the passenger seat writing down the speed and forces. Should work. I'd be interested to read your results. Mike Quote Share this post Link to post Share on other sites
sundevil777 93 #6 October 18, 2004 Or just get somebody with Dan Poynter's manual to look it up. It does at least have some data points as a starter for the curious.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
mjosparky 3 #7 October 18, 2004 QuoteIf you want to rig a setup like this, my suggestion is to do it from the back of a pickup truck, mount the scale to something firmly attached to the truck, and have somebody in the bed monitor the scale (and/or film it). Two way radios would aid in communication. Then you can have somebody in the passenger seat writing down the speed and forces. Should work. I'd be interested to read your results. Mike I would like to be there and watch when this P/U truck is driven at 100 to 200 mph with a PC in tow. The average hand deploy PC, at terminal, arould 120 +/- will produce over 100 pounds of drag. I not as detailed at you asked for but that is all I have tested to. SparkyMy idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites
gus 1 #8 October 18, 2004 QuoteThe base guys had a excel on a website, but the link was bad Try this. If it doesn't work I can email it to you. GusOutpatientsOnline.com Quote Share this post Link to post Share on other sites
billbooth 10 #9 October 18, 2004 I actually did the "pick-up truck" test about 30 years ago. The results are kinda' fuzzy, but did work out to about one pound, per mile per hour, on a 36" pilot chute. The drag on smaller sizes with be in proportion to the relative area of the pilot chute. For instance a 36" pilot chute has an area of 1017.36 square inches. A 27" pilot has an area of 572.265 square inches, or just more than half the area (56.25%) of a 36" chute. (Of course, these are "flat" areas, not inflated areas, but will do for the purpose of example.) Anyway, half the area equals half the drag. So if a 36"er pulls 120 lbs at 120 mph, the a 27"er should pull 67.5 lbs. at 120 mph. Quote Share this post Link to post Share on other sites
cvfd1399 0 #10 October 18, 2004 Well the data in his book that I could find only had it at 35 mph. The other data was in a wind tunnel at 120 mph which at this point is the only number I have. Quote Share this post Link to post Share on other sites
cvfd1399 0 #11 October 18, 2004 Thanks bill that is the ball park figures I was looking for. The reason for the season was to see how much pressure is applied to the bridle and pin at the attachment point. Quote Share this post Link to post Share on other sites
pilotdave 0 #12 October 18, 2004 Keep in mind that real world factors complicate things a lot. I mean, you can probably get a decent ballpark figure which I'm sure is all you need, but actual forces get very tricky. I mean, just because the PC develops X pounds of drag doesn't mean that X pounds of force gets transmitted to the pin. It's also a dynamic situation vs. static... assuming you don't have a PC in tow. But if you were looking for a realistic number, you'd need to know a lot more than just the drag that the PC can generate. Dave Quote Share this post Link to post Share on other sites
mjosparky 3 #13 October 18, 2004 QuoteI actually did the "pick-up truck" test about 30 years ago. The results are kinda' fuzzy, but did work out to about one pound, per mile per hour, on a 36" pilot chute. The drag on smaller sizes with be in proportion to the relative area of the pilot chute. For instance a 36" pilot chute has an area of 1017.36 square inches. A 27" pilot has an area of 572.265 square inches, or just more than half the area (56.25%) of a 36" chute. (Of course, these are "flat" areas, not inflated areas, but will do for the purpose of example.) Anyway, half the area equals half the drag. So if a 36"er pulls 120 lbs at 120 mph, the a 27"er should pull 67.5 lbs. at 120 mph. Bill, I take it you were using a PC made of a lopo type material? With a 27" ZP PC, I maxed out a 100 pound scale at just over 95 mph. SparkyMy idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites
billbooth 10 #14 October 18, 2004 Back then it probably was very porous fabric. ZP fabric would obviously pull more. Quote Share this post Link to post Share on other sites
cvfd1399 0 #15 October 18, 2004 You would know why I am asking this sparky. My MT1-XXagve me 2 floating ripcords(both I reached and found) this weekend so I had it changed to BOC. My rigger sewed a spandex pouch on the bottom of the rig, a 3 inch piece of velcro that leads from the mouth of the pouch to under the flap that the bridle goes on. Then we installed a approx7' bridle and a 36'' pilot chute. I have yet to jump it. You think the 36'' is good enough. I have already jumped the DZ's MT1-XX that has been converted this way, and I love it. A little more about the floting ripcords. The main deployment ripcord fits outboard on the right MLW. It fits sung in the pocket, but on 2 consecutive RW jumps it came out in my track near pull time. I just looked over at it and deployed like normal. Quote Share this post Link to post Share on other sites
mjosparky 3 #16 October 18, 2004 PM sent. SparkyMy idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites
