Jonsmann 0 #1 September 2, 2002 Anyone know the normal range of pilot chute pull force? (assuming normal fall rate and deployment altitude etc.). Guesses are fine, but I would prefer to hear from people who actually know! - Jacques Quote Share this post Link to post Share on other sites
Viking 0 #2 September 2, 2002 Enough to pull your pin and main bag off your back.........I swear you must have footprints on the back of your helmet - chicagoskydiver My God has a bigger dick than your god -George Carlin Quote Share this post Link to post Share on other sites
billvon 3,090 #3 September 2, 2002 >Anyone know the normal range of pilot chute pull force? (assuming > normal fall rate and deployment altitude etc.). There are a lot more than that, like jumpsuit type, jumper size, type of pilot chute etc. I don't have any hard numbers for freefall speeds, but here are some for some reserve PC's at lower speeds: racer RPC drag at 35 mph: 18 lbs reflex RPC drag at 35 mph: 15 lbs reflex RPC and CPC drag at 35 mph: 22 lbs 36" F111 PC drag at 35 mph: 15 lbs 46" zero-P PC drag at 35 mph: 27 lbs (note: RPC and CPC refer to reserve pilot chute and catapult pilot chute) Quote Share this post Link to post Share on other sites
alan 1 #4 September 3, 2002 As has been stated, many variables will affect the drag of a PC. Generally speaking, the most common rule of thumb number I have seen is about 80# at terminal. Just for fun, get a spring scale and attach a PC to it then hang onto the scale outside of a car window. SLOWLY accellerate and observe the scale for as long as you can hang on. I'd bet you'll never get to 120 mph. OK, OK, so this isn't very scientific and you'll most likely dislocate your shoulder, but hey, "guesses are fine" and it will make a good bonfire story.alan Quote Share this post Link to post Share on other sites
riggerrob 643 #5 September 3, 2002 Relative Workshop expects main pilotchutes to provide about 80 pounds of drag at terminal velocity. Quote Share this post Link to post Share on other sites
CanEHdian 0 #6 September 4, 2002 Been wanting to bring this up... With the amount of drag (whatever the exact number, we can agree that it's a lot) that a PC provides - why do some folks still list a short closing loop/too tight pin as a possible cause for PC in tow?Time's flying, and so am I... (69-way, 108-way and 138/142-way Freefly World Records) Quote Share this post Link to post Share on other sites
skymedic 0 #7 September 4, 2002 Cause you can make it too tight.... Marc otherwise known as Mr.Fallinwoman.... Quote Share this post Link to post Share on other sites
Jimbo 0 #8 September 4, 2002 QuoteCause you can make it too tight.... Really, how tight would it have to be to prevent the pilot chute from extracting the pin? I can't imagine a situation where the pilot chute was functioning correctly and couldn't extract the pin. Anyone have a real case where they've actually seen this happen? - Jim"Like" - The modern day comma Good bye, my friends. You are missed. Quote Share this post Link to post Share on other sites
kallend 2,117 #9 September 4, 2002 Quote QuoteCause you can make it too tight.... Really, how tight would it have to be to prevent the pilot chute from extracting the pin? I can't imagine a situation where the pilot chute was functioning correctly and couldn't extract the pin. Anyone have a real case where they've actually seen this happen? - Well, real data would spoil all the fun, wouldn't it? Quote Share this post Link to post Share on other sites
indyz 1 #10 September 4, 2002 QuoteReally, how tight would it have to be to prevent the pilot chute from extracting the pin? I can't imagine a situation where the pilot chute was functioning correctly and couldn't extract the pin. I am not an expert by any means, but... Right now my closing loop is very tight. If I do a loose (bulky) pack job, I am at the end of my strength to get the pin in with just a pull-up cord. The pin is secure in that it doesn't move around easily, but I can still extract the pin with my fingers, using nowhere near 80 pounds, or even 20 pounds, of force. The pin still comes out if I grab the bridle and lift straight up, without lifting the rig off of the ground at all. All of that with the loop so tight that if I shortened it any more, I wouldn't be able to close it without some sort of mechanical assistance. Quote Share this post Link to post Share on other sites
Jimbo 0 #11 September 4, 2002 QuoteRight now my closing loop is very tight. If I do a loose (bulky) pack job, I am at the end of my strength to get the pin in with just a pull-up cord. The pin is secure in that it doesn't move around easily, but I can still extract the pin with my fingers, using nowhere near 80 pounds, or even 20 pounds, of force. The pin still comes out if I grab the bridle and lift straight up, without lifting the rig off of the ground at all. All of that with the loop so tight that if I shortened it any more, I wouldn't be able to close it without some sort of mechanical assistance. My point exactly. I suspect that one might be able to induce a pilot chute in tow with an extraordinarily tight closing loop and a damaged pin (think a rough spot or gouged area in the pin or maybe a severely bent pin.) This of course can be prevented with proper gear inspection/maintenance. - Jim"Like" - The modern day comma Good bye, my friends. You are missed. Quote Share this post Link to post Share on other sites
billvon 3,090 #12 September 4, 2002 > I can't imagine a situation where the pilot chute was functioning > correctly and couldn't extract the pin. Neither can I. However, with the number of incorrectly assembled and maintained PC's that I've seen (shrunken kill lines, reinforcements in the wrong place, ancient F111 material) it may not be prudent to assume a perfectly functioning PC. Add a nicked pin and a tight pack job and you could have a problem. I think any serious problem in skydiving is the result of several small problems adding up to a big one. The trick is not letting all of them come together at the same time. Quote Share this post Link to post Share on other sites
ernokaikkonen 0 #13 September 4, 2002 QuoteI think any serious problem in skydiving is the result of several small problems adding up to a big one. The trick is not letting all of them come together at the same time. I don't think a tight closing loop should be classified as a problem. The problems would be a worn out pilot chute and/or nicked pin. Seriously, you are not suggesting a loose closing loop to prevent a PC in tow? Erno Quote Share this post Link to post Share on other sites
Jimbo 0 #14 September 4, 2002 QuoteSeriously, you are not suggesting a loose closing loop to prevent a PC in tow? I understood Bill's comment to mean keep your gear in top condition to prevent a pilot chute in tow. A loose closing pin is just asking for a whole new set of problems. - Jim"Like" - The modern day comma Good bye, my friends. You are missed. Quote Share this post Link to post Share on other sites
jurgencamps 0 #15 September 6, 2002 "Relative Workshop expects main pilotchutes to provide about 80 pounds of drag at terminal velocity" In the same test they found that the force needed to extract the pin from the closing loop never exceeds 10 pound (article in an US skydiving magazine) Quote Share this post Link to post Share on other sites
