jraylitt 0 #1 May 15, 2011 Whats the average speed of a skydiver in the belly to earth position? Expressed in feet per second. How long does it take to reach terminal? (belly to earth) How long does it take fall 1k feet? (belly to earth) thanks for any reply's Quote Share this post Link to post Share on other sites
Remster 24 #2 May 15, 2011 You want exact numbers, or what people use as rough every day approximations? Exact numbers will vary on every jump. Approximations: - 115 to 125 mph typical terminal velocity in belly to earth - About 12 seconds to reach that speed - About 5 seconds per 1000 feet at that speed.Remster Quote Share this post Link to post Share on other sites
jraylitt 0 #3 May 15, 2011 that's pretty much what I was going after....roughly. Quote Share this post Link to post Share on other sites
grannyinthesky 0 #4 May 15, 2011 I regularly have my math classes do the conversion. 120mph is equal to 176 feet per second. "safety first... and What the hell..... safety second, Too!!! " ~~jmy POPS #10490 Quote Share this post Link to post Share on other sites
ryoder 1,381 #5 May 15, 2011 Laden, or unladen?"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones. Quote Share this post Link to post Share on other sites
Remster 24 #6 May 15, 2011 European or African?Remster Quote Share this post Link to post Share on other sites
theonlyski 3 #7 May 15, 2011 QuoteEuropean or African? Don't forget, it depends which hemisphere you're in, as the toilets flushing a different way have an effect on the amount of gravity pulling."I may be a dirty pirate hooker...but I'm not about to go stand on the corner." iluvtofly DPH -7, TDS 578, Muff 5153, SCR 14890 I'm an asshole, and I approve this message Quote Share this post Link to post Share on other sites
PiLFy 0 #8 May 15, 2011 You've got 37 jumps, & they didn't teach you this? Average belly-to-earth freefall speed is 120MPH. 120MPH = 176 feet per second. It takes about ten seconds to reach terminal. @176FPS, 1K' is a hair over five seconds. I'd love to give you a personal demonstration. Trouble is, it's been raining every F'ing weekend x at least six weeks. It's supposed to rain for the next seven days straight around here, as well. Quote Share this post Link to post Share on other sites
godfrog 2 #9 May 16, 2011 QuoteQuoteEuropean or African? Don't forget, it depends which hemisphere you're in, as the toilets flushing a different way have an effect on the amount of gravity pulling.[/reply __________________________________________________ It will also dictate which way you will spin, due to the corealis effect, if you spin to the right in the northern hemisphere you will spin to the left in the southern hemisphere!Experience is a difficult teacher, she gives you the test first and the lesson afterward Quote Share this post Link to post Share on other sites danielcroft 2 #10 May 16, 2011 What if they griped it by the husk? Quote Share this post Link to post Share on other sites jumpsalot-2 2 #11 May 16, 2011 With a helmet or without ?Life is short ... jump often. Quote Share this post Link to post Share on other sites sundevil777 93 #12 May 16, 2011 QuoteEuropean or African? To get back to serious considerations... L&B products allow the choice of TAS-true airspeed or SAS-skydiver airspeed (SAS provides the choice to "normalize" the speed to what it would be at a std air density). The normalized (SAS) speed is better to use when discussing fall rates. It is regrettable that the Neptune doesn't seem to offer a similar normalized speed (the manual doesn't seem to have a choice). I don't know about other mfgs dataloggers. To not use SAS means there will always be some error in the comparison due to the altitude at which the speed was measured.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 GLIDEANGLE 1 #13 May 16, 2011 I know you Asked for typical. However, I thought you might find it interesting that I had two big AFF students this weekend who fell at ~143 mph in stable belly flight. On the other hand I have heard of large, dense belly formations slow to almost 100 mph.The choices we make have consequences, for us & for others! Quote Share this post Link to post Share on other sites jraylitt 0 #14 May 16, 2011 So If I have an altitrack have it set to SAS.??? Quote Share this post Link to post Share on other sites sundevil777 93 #15 May 16, 2011 QuoteSo If I have an altitrack have it set to SAS.??? If everyone had instruments that had the choice to show a normalized speed, then it would be more valid to make comparisons. It would be better if everyone realized that there is a difference, and when using fall rate numbers specified whether it was SAS, or TAS. From L&B manual: "TAS/SAS Definitions True Airspeed (TAS) and Skydiver’s Airspeed (SAS) are two methods of calculating the airspeed of a moving/flying/falling object. TAS is a term used in aviation: It is the speed of an object relative to the surrounding air, regardless of the altitude. SAS is a new concept developed by LARSEN & BRUSGAARD: SAS is the speed of a skydiver calculated from measurements of air pressure and temperature and converted to a fixed air pressure (875.3 mb) and a fixed temperature (+7.080C) which corresponds to 4,000 feet ASL. TAS A skydiver’s True Airspeed (TAS) relative to the ground changes as a function of the altitude (air pressure) and temperature which makes it difficult to compare fall-rates. Example: A skydiver (in a fixed freefall position) who has a terminal fallrate of 62 meters/sec at 10,000 feet will have a terminal fallrate of 50 meters/sec at 3,000 feet. It will be seen that the difference in altitude (air pressure) makes it difficult to compare the fall-rates when measured using TAS. SAS The SAS formula calculates airspeed (using the same metrics used with TAS) as though the complete skydive had been performed at a fixed air pressure and a fixed temperature which corresponds to 4,000 feet ASL. 4,000 feet is chosen as the reference altitude by LARSEN & BRUSGAARD since this is the average altitude at which the working time of a skydive is normally ended. Conclusion Using SAS, skydivers in any body position can express their vertical speed by a number (SAS). This number remains virtually constant regardless of altitude with little or no variance due to temperature differences and can be compared with the airspeeds of other skydivers. This means that regardless of the elevation of the DZ you are jumping at, SKYDIVER’S AIRSPEED (SAS) will be the same for the same body position. SAS is very useful when doing big formation skydiving. If using TAS, it will seem like the base is slowing down the fall rate during the entire skydive."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 PiLFy 0 #16 May 16, 2011 "I had two big AFF students this weekend who fell at ~143 mph in stable belly flight." Daaaaaamn. How many pounds were they? Quote Share this post Link to post Share on other sites 3mpire 0 #17 May 17, 2011 I met a guy recently who must have barely weighed 100 pounds who told me he put on a huuuuuuuge baggy suit for fun and clocked in at 83 MPH. Quote Share this post Link to post Share on other sites jraylitt 0 #18 May 18, 2011 I weigh 205. My Altitrack had me at an average speed of 133 mph and 144 mph max speed on my last dive. Mostly belly flying with some tracking. Thats fast. Quote Share this post Link to post Share on other sites Remster 24 #19 May 18, 2011 How short are you?Remster 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. Insert image from URL × Desktop Tablet Phone Submit Reply 0
danielcroft 2 #10 May 16, 2011 What if they griped it by the husk? Quote Share this post Link to post Share on other sites
jumpsalot-2 2 #11 May 16, 2011 With a helmet or without ?Life is short ... jump often. Quote Share this post Link to post Share on other sites
sundevil777 93 #12 May 16, 2011 QuoteEuropean or African? To get back to serious considerations... L&B products allow the choice of TAS-true airspeed or SAS-skydiver airspeed (SAS provides the choice to "normalize" the speed to what it would be at a std air density). The normalized (SAS) speed is better to use when discussing fall rates. It is regrettable that the Neptune doesn't seem to offer a similar normalized speed (the manual doesn't seem to have a choice). I don't know about other mfgs dataloggers. To not use SAS means there will always be some error in the comparison due to the altitude at which the speed was measured.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
GLIDEANGLE 1 #13 May 16, 2011 I know you Asked for typical. However, I thought you might find it interesting that I had two big AFF students this weekend who fell at ~143 mph in stable belly flight. On the other hand I have heard of large, dense belly formations slow to almost 100 mph.The choices we make have consequences, for us & for others! Quote Share this post Link to post Share on other sites
jraylitt 0 #14 May 16, 2011 So If I have an altitrack have it set to SAS.??? Quote Share this post Link to post Share on other sites
sundevil777 93 #15 May 16, 2011 QuoteSo If I have an altitrack have it set to SAS.??? If everyone had instruments that had the choice to show a normalized speed, then it would be more valid to make comparisons. It would be better if everyone realized that there is a difference, and when using fall rate numbers specified whether it was SAS, or TAS. From L&B manual: "TAS/SAS Definitions True Airspeed (TAS) and Skydiver’s Airspeed (SAS) are two methods of calculating the airspeed of a moving/flying/falling object. TAS is a term used in aviation: It is the speed of an object relative to the surrounding air, regardless of the altitude. SAS is a new concept developed by LARSEN & BRUSGAARD: SAS is the speed of a skydiver calculated from measurements of air pressure and temperature and converted to a fixed air pressure (875.3 mb) and a fixed temperature (+7.080C) which corresponds to 4,000 feet ASL. TAS A skydiver’s True Airspeed (TAS) relative to the ground changes as a function of the altitude (air pressure) and temperature which makes it difficult to compare fall-rates. Example: A skydiver (in a fixed freefall position) who has a terminal fallrate of 62 meters/sec at 10,000 feet will have a terminal fallrate of 50 meters/sec at 3,000 feet. It will be seen that the difference in altitude (air pressure) makes it difficult to compare the fall-rates when measured using TAS. SAS The SAS formula calculates airspeed (using the same metrics used with TAS) as though the complete skydive had been performed at a fixed air pressure and a fixed temperature which corresponds to 4,000 feet ASL. 4,000 feet is chosen as the reference altitude by LARSEN & BRUSGAARD since this is the average altitude at which the working time of a skydive is normally ended. Conclusion Using SAS, skydivers in any body position can express their vertical speed by a number (SAS). This number remains virtually constant regardless of altitude with little or no variance due to temperature differences and can be compared with the airspeeds of other skydivers. This means that regardless of the elevation of the DZ you are jumping at, SKYDIVER’S AIRSPEED (SAS) will be the same for the same body position. SAS is very useful when doing big formation skydiving. If using TAS, it will seem like the base is slowing down the fall rate during the entire skydive."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
PiLFy 0 #16 May 16, 2011 "I had two big AFF students this weekend who fell at ~143 mph in stable belly flight." Daaaaaamn. How many pounds were they? Quote Share this post Link to post Share on other sites
3mpire 0 #17 May 17, 2011 I met a guy recently who must have barely weighed 100 pounds who told me he put on a huuuuuuuge baggy suit for fun and clocked in at 83 MPH. Quote Share this post Link to post Share on other sites
jraylitt 0 #18 May 18, 2011 I weigh 205. My Altitrack had me at an average speed of 133 mph and 144 mph max speed on my last dive. Mostly belly flying with some tracking. Thats fast. Quote Share this post Link to post Share on other sites
Remster 24 #19 May 18, 2011 How short are you?Remster Quote Share this post Link to post Share on other sites
