A101080 0 #1 November 7, 2001 I was wondering if any of you could help me with working out my free-fall times. What would be the average decent rate for someone (ie: me) who weighs approximately 165 llb / 75 kg without rig and how long would it take to reach this speed after exiting from 13k?I understand that a some log books have this sort of info contained in tables at the back - but mine doesn't.Any ideas would be greatly appreciated.Alex.Be gentle with me..... it's my first time! Quote Share this post Link to post Share on other sites
jfields 0 #2 November 7, 2001 Quoteit's my first time!Beer!From my understanding, it takes about 10 seconds to reach terminal, which is generally about 110 mph or so. It can vary based on your body type (skinny, dense, tall, short, etc.) and your body position (arched, flat, cupping, sit, etc.).I think the USPA says approximately 5.5 seconds per 1000 feet of belly-flying. So about 10 seconds for the first 1000, plus 5.5 per thousand thereafter. Ballpark estimate, of course.Someone will probably post more specific data, but that is the general idea.JustinMy Homepage Quote Share this post Link to post Share on other sites
SkymonkeyONE 4 #3 November 7, 2001 The old school says that that you accelerate at a rate of 32 feet per second until reaching your terminal velocity at 12 seconds of freefall. Today, with all the varying methods of freefall, a person might average from 35mph (birdman flight) to over 240mph (speed skydiving). The Protrack is a neat tool to get fairly precise freefall times, though I am not about to spend $350 on one. ChuckMy webpage HERE Quote Share this post Link to post Share on other sites
skreamer 1 #4 November 7, 2001 Quotesomeone (ie: me) who weighs approximately 165 llb / 75 kg without rig and how long would it take to reach this speed after exiting from 13kUhh, dude, I have to tell you skydiving is a hazardous activity and could result in injury or death HOWEVER wearing a skydiving rig will greatly reduce the chance of your dying!!! Just kidding man, I was just curious about why you wanted to know about reaching termincal velocity without a rig. Quote Share this post Link to post Share on other sites
mountainman 0 #5 November 7, 2001 QuoteI am not about to spend $350 on oneWow!! Where do you shop, smONE?? Nieman Marcus?? I ordered mine for $240 during the boogie and you can get them for $250 from ParaQuip anytime.--------------click me for a good time Quote Share this post Link to post Share on other sites
jfields 0 #6 November 7, 2001 Brandon,ParaQuip actually sells them for $285 now. About the same as Square1 and Paragear. Expensive little boogers!JustinMy Homepage Quote Share this post Link to post Share on other sites
mountainman 0 #7 November 7, 2001 Oops......my fault. Last time I looked, they were $250 and we got ours for $10 cheaper cuz they were our at the time. Still, it's cheaper than $350!!!Umm.....I think you can get them from ParaGear for $260.96. They are on sale there, so get it now!--------------click me for a good time Quote Share this post Link to post Share on other sites
174fps 1 #8 November 7, 2001 CSPA uses 1500' in 12sec to terminal then 5s per 1000'13000' to pull at 3500 equals 9500' free fall. 1500' 12s 8000' 40s equals 52sfffor the detailed calculation 1483' in 12s then 174fps thereafter.this is for belly flying , sit or headdown will be faster.174fps Quote Share this post Link to post Share on other sites
SkymonkeyONE 4 #9 November 7, 2001 Quotewhere do you shop?Actually, that was just a guess as I have never considered buying one of those things. A regular old dytter is what I use.ChuckMy webpage HERE Quote Share this post Link to post Share on other sites
Donna 0 #10 November 7, 2001 Here is a chart from a logbook with average times based on a deployment altitude of 2500 feet.Exit Altitude / Relative Work (109 mph) / Freestyle (120 mph)2500 / 0 / 03000 / 6 / 63500 / 10 / 94000 / 13 / 124500 / 16 / 155000 / 20 / 185500 / 23 / 216000 / 26 / 246500 / 29 / 267000 / 32 / 297500 / 35 / 328000 / 39 / 358500 / 42 / 389000 / 45 / 419500 / 48 / 4310000 / 51 / 4610500 / 54 / 4911000 / 57 / 5211500 / 61 / 5512000 / 64 / 5812500 / 67 / 6013000 / 70 / 6313500 / 73 / 6614000 / 76 / 69The use of freestyle was the logbooks choice, not mine. Notice it says freestyle, not freefly. Freeflyers typically go much faster than that. I do have a protrack (which I paid $240 for) and it usually gives me an average speed in the 120s while doing small rw work. I'm not sure how accurate that is. I wear it in my helmet because I use it as an audible altimeter and for more accurate readings on speed you should wear it on your leg. Or you can do what my husband does which is just put 60 seconds for a typical jump. Skies,D Quote Share this post Link to post Share on other sites
SkymonkeyONE 4 #11 November 7, 2001 And I normally log 72 seconds for jumps from altitude. My webpage HERE Quote Share this post Link to post Share on other sites
A101080 0 #12 November 7, 2001 skreamer,It's not that I planned to jump without a rig, it's just that as I don't own one (I have to rent), I don't know how much they weigh - I would guess that it would be about 20llbs(ish) / 10 kg, but it would only be a guess!I appreciate your concern for my safety though !Alex. Quote Share this post Link to post Share on other sites
VivaHeadDown 0 #13 November 7, 2001 120 seconds for RW work??? That's two minutes...something isn't right here. Quote Share this post Link to post Share on other sites
A101080 0 #14 November 7, 2001 All,Thanks for all the info so far. Is it me or does it seem a bit odd that different people / associations use different ways of calculating this stuff?Oh, and as I can't even afford a rig yet, I certainly won't be spending money on a Dyter - however much they cost - just to find out my exact fall rate! Alex.PS: I'm flying flat (or trying to)! Quote Share this post Link to post Share on other sites
rgoper 0 #15 November 7, 2001 Alex:if your not sure what a rig weighs, that tells me that maybe you might not have a handle on wing loading either, you've been provided a good chart here for fall rate, that should get you started there. but do some research into wing loading, if you haven't already. take care, be safe!RichardGravity Is My Firend Quote Share this post Link to post Share on other sites
SpeedRacer 1 #16 November 7, 2001 Quote120 seconds for RW work??? That's two minutes...something isn't right here Hey Viva I think that "average speed in the 120s" means in the 120-129 mph range. Not 120 seconds.Speed RacerThe problem with the world is that everyone is a few drinks behind-Bogart Quote Share this post Link to post Share on other sites
apoil 0 #17 November 7, 2001 QuoteThe old school says that that you accelerate at a rate of 32 feet per second until reaching your terminal velocity at 12 seconds of freefallThat's not quite the old school, because even then it would be wrong.First off, it's 32 feet per second per second. or feet per second squared.What does that mean? Well you are measuring accelleration which is a change in speed. Speed is in feet per second. So every second, your speed increases by 32 feet per second.. hence 32 (feet per second) per second.Now why is that wrong? Because you don't just suddently stop accellerating when you hit terminal velocity. That would hurt! The reason why you reach terminal velocity in the first place is because your acceleration decreases with wind resistance, which is a function of how fast you're going. Stay with me here, it's not hard even for those of you who hate math and physics.32f/s/s is the acceleration in a vacuum. No wind. You start out that way, so at the end of the first second, you will be falling at about 32 feet persecond, but after that wind resistance will kick in. It will get stronger the longer you fall, reducing your rate of accelleration until the force of gravity pulling down is equal to the force of wind resistance pushing up. When all forces are in balance you move at a constant speed. Thing is, terminal velocity depends on your weight and shape, hence the wide range of speeds for falling people. But in the basic belly fly position it's roughly between 105 - for a 6'5" guy weighing 140 pounds to around 130 or more - someone 5'8" weighing 230lbs. So you can't calculate exactly what your wind resistance is, and even if you could it would take some pretty advanced math to get it right. And even then, the differences in your calculations would only amount to a few seconds anyway.Just use the rule of thumb - 10-12 seconds to cover the first 1000 feet, assume you are terminal by then and take 5-6 seconds per thousand after that.Or get a protrack. Quote Share this post Link to post Share on other sites
jfields 0 #18 November 8, 2001 Damn scary edumukated answer, Apoil. JustinMy Homepage Quote Share this post Link to post Share on other sites
wingnut 0 #19 November 8, 2001 ow,, my head hurts now.... i just use the little chart in my log book..... works for me......... if i really cared i'd by a protrac.........but it's just one more thing to break or lose....."up my noooossseee"- wingnut, at first euro dz.com boogie Quote Share this post Link to post Share on other sites
SkymonkeyONE 4 #20 November 8, 2001 That bugs me tremendously....not really[grin]yeah, I forgot the other "per second", but then again I have been out of the engineering mindset for quite some time now. ChuckMy webpage HERE Quote Share this post Link to post Share on other sites
RemiAndKaren 0 #21 November 9, 2001 If you're keen on exactness, get a protrack... if you're happy with approximations, pick a number! I use 65 sec for 12,500 to 2,500 and add 5 sec for each 1K (RW)... close enough for government work...RemiMuff 914 Quote Share this post Link to post Share on other sites
