# Is it possible to parachute safely to earth from a tall building using a bedsheet? **URL:** \ **Category:** Factual Questions\ **Created:** [August 18, 2012, 12:56am UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834 "2012-08-18T00:56:52Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 18, 2012, 10:09pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/21 "2012-08-18T22:09:43Z")
> [@Dr.Strangelove](#): > > That doesn’t make much sense. Unless you’re actually being accelerated upward, you’ll never experience a force beyond your own weight. If you can hang from a static piece of plywood, then you can use one as a parachute. A sheet of plywood is likely to ‘flutter’ though - and this would probably exert sudden forces on your hands. ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [August 18, 2012, 10:10pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/22 "2012-08-18T22:10:19Z")
> [@njtt](#): > > I do not see how two corners could possibly work, even if you were somehow able to hold on (and even if a bed sheet were big enough); you would need to hold at least three, and preferably four, to catch any air. The O.P. said > [@Dickie.and.his.cat](#): > > I mean by holding two corners of the sheet in either hand. If you hold two corners in each hand, you are holding all four corners. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 18, 2012, 10:12pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/23 "2012-08-18T22:12:58Z")
> [@Peanuthead](#): > > What if you tied the four corners together? Tie the corners criss cross under your crotch and you’d have a sort of harness or saddle. By the time you’ve knotted the corners securely under your crotch, what you’ve got left is little more than a sack, and you’re inside it. ---
**Author:** ![Hail\_Ants](https://avatars.discourse-cdn.com/v4/letter/h/dc4da7/32.png) [@Hail\_Ants](https://boards.straightdope.com/u/Hail_Ants)\ **Post date:** [August 18, 2012, 10:26pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/24 "2012-08-18T22:26:43Z")
> [@Fubaya](#): > > Most parachutes for an average adult\* need to 100-200 square feet. A king size bed is about 42 square feet. Parachutes are made of materials that catch the wind like silk or nylon while bed sheets are made of cotton that wouldn’t slow the air down as much. > > - using old timey average American adult size of about 150 lbs. To add to this, the very smallest parachutes, the high-performance square ones, are specifically designed to not just create drag but to act as an airfoil or wing (IOW convert downward vertical motion into survivable & controllable horizontal motion). Also if you had a bed sheet approaching sufficient size to generate sufficient drag, the forces on it would instantly cause bed sheet fabric to shred. Lesson: Don’t use a parachute from the **Acme** ™ Corporation… ---
**Author:** ![Bumbershoot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bumbershoot/32/3428_2.png) [@Bumbershoot](https://boards.straightdope.com/u/Bumbershoot)\ **Post date:** [August 18, 2012, 11:14pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/25 "2012-08-18T23:14:20Z")
Nope. The inflation of the sheet when it catches air will rip it right out of your hands. You’ll have to reach a certain speed for the sheet to inflate and opening shock will be significant. I don’t know if anyone has the hand or arm strength to hold on. Plus as others have pointed out a bedsheet is too small. **Fubaya** was right, a lot of experienced skydivers use parachutes in the 100-200 sq. ft. range (When I was an active skydiver, my main canopy was 190 sq. ft.). A bedsheet would have to be quite a bit larger than it is, and made out of something strong like nylon to survive opening shock. ---
**Author:** ![Siam\_Sam](https://avatars.discourse-cdn.com/v4/letter/s/d78d45/32.png) [@Siam\_Sam](https://boards.straightdope.com/u/Siam_Sam)\ **Post date:** [August 19, 2012, 2:06am UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/26 "2012-08-19T02:06:31Z")
> [@aldiboronti](#): > > I’m sure an umbrella would work. > > [Oh, wait a minute …](http://www.abs-cbnnews.com/global-filipino/09/02/10/maid-uses-umbrella-parachute-dies-report) > > Back to the drawing board! > > BTW thinking about how the Saudis treat their domestics I’m inclined to put this down to sheer desperation rather than stupidity. I could see this happening too in Singapore with an Indonesian maid. ---
**Author:** ![Dickie.and.his.cat](https://avatars.discourse-cdn.com/v4/letter/d/f0a364/32.png) [@Dickie.and.his.cat](https://boards.straightdope.com/u/Dickie.and.his.cat)\ **Post date:** [August 19, 2012, 12:50pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/27 "2012-08-19T12:50:09Z")
> [@Bumbershoot](#): > > Nope. The inflation of the sheet when it catches air will rip it right out of your hands. You’ll have to reach a certain speed for the sheet to inflate and opening shock will be significant. I don’t know if anyone has the hand or arm strength to hold on. I’m sure I remember seeing a video of someone jumping from one of the ‘twin towers’ holding onto something ‘sheet like’? Anyway it happened the way you say, in that it got ripped out of their hands almost immediately. ---
**Author:** ![clairobscur](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@clairobscur](https://boards.straightdope.com/u/clairobscur)\ **Post date:** [August 19, 2012, 1:20pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/28 "2012-08-19T13:20:45Z")
> [@aldiboronti](#): > > I’m sure an umbrella would work. > . Tested that as a kid. Doesn’t work. ☹ ---
**Author:** ![simster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/simster/32/1047_2.png) [@simster](https://boards.straightdope.com/u/simster)\ **Post date:** [August 19, 2012, 1:35pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/29 "2012-08-19T13:35:01Z")
> [@Mangetout](#): > > By the time you’ve knotted the corners securely under your crotch, what you’ve got left is little more than a sack, and you’re inside it. aids in the cleanup - ---
**Author:** ![Jake](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@Jake](https://boards.straightdope.com/u/Jake)\ **Post date:** [August 21, 2012, 6:33pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/30 "2012-08-21T18:33:23Z")
> [@Tom\_Tildrum](#): > > Superman and Jimmy Olsen used S’s cape as a parachute in Kandor one time, but the atmosphere there is denser. Not as dense as those two! 😛 ---
**Author:** ![Valgard](https://avatars.discourse-cdn.com/v4/letter/v/7feea3/32.png) [@Valgard](https://boards.straightdope.com/u/Valgard)\ **Post date:** [August 21, 2012, 9:26pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/31 "2012-08-21T21:26:52Z")
> [@Leo\_Bloom](#): > > How did you arrive at this figure? I used to skydive a lot and that’s a pretty accurate range - with older uncoated F111 nylon you’d go for a loading of around 1psf for the average jumper. When coated zero-porosity fabrics hit the market and canopies could handle much higher wing loadings, manufacturers began moving to elliptical and semi-elliptical wings that were loaded up around 1.5psf (and probably higher nowadays with very experienced canopy flyers). The smallest main canopy on the market when I stopped jumping (years ago) was 77 square feet which is incredibly tiny. As noted above, ram-air canopies are actually inflatable wings - lots of forward speed and plenty of lift (compared to older rounds and the like) - so you’re not just dropping straight down. ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [August 21, 2012, 9:37pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/32 "2012-08-21T21:37:29Z")
> [@Dickie.and.his.cat](#): > > I’m sure I remember seeing a video of someone jumping from one of the ‘twin towers’ holding onto something ‘sheet like’? > Anyway it happened the way you say, in that it got ripped out of their hands almost immediately. I saw that too. Within seconds it was ripped from his hands. Probably a table cloth. ---
**Author:** ![Kenm](https://avatars.discourse-cdn.com/v4/letter/k/bc79bd/32.png) [@Kenm](https://boards.straightdope.com/u/Kenm)\ **Post date:** [August 21, 2012, 9:41pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/33 "2012-08-21T21:41:53Z")
> [@Tom\_Tildrum](#): > > Superman and Jimmy Olsen used S’s cape as a parachute in Kandor one time, but the atmosphere there is denser. And property values are sky high. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [August 21, 2012, 10:10pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/34 "2012-08-21T22:10:45Z")
> [@aldiboronti](#): > > I’m sure an umbrella would work. > > [Oh, wait a minute …](http://www.abs-cbnnews.com/global-filipino/09/02/10/maid-uses-umbrella-parachute-dies-report) > > Back to the drawing board! > > BTW thinking about how the Saudis treat their domestics I’m inclined to put this down to sheer desperation rather than stupidity. It didn’t work out for her because she was a housemaid, not [a nanny](http://en.wikipedia.org/wiki/Mary_poppins). :smack: Yeah, it’s insensitive, but I couldn’t possibly be the only one who thought of it. ---
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [August 22, 2012, 6:50pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/35 "2012-08-22T18:50:11Z")
> [@Fubaya](#): > > Parachutes are made of materials that catch the wind like silk or nylon while bed sheets are made of cotton that wouldn’t slow the air down as much. I’m not sure what that means. I think the reason silk and later nylon were chosen is the strength to weight ratio is much higher. Cotton has to be fairly thick and thus heavy to hold together, meaning a much larger parachute for the overall product. A canvas sail would be strong enough, but weigh more than the person it is holding. And folded would be bigger than the person trying to carry it. > [@njtt](#): > > I do not see how two corners could possibly work, even if you were somehow able to hold on (and even if a bed sheet were big enough); you would need to hold at least three, and preferably four, to catch any air. 2 corners each hand = 4 corners. [QUOTE=Valgard] I used to skydive a lot and that’s a pretty accurate range - with older uncoated F111 nylon you’d go for a loading of around 1psf for the average jumper. When coated zero-porosity fabrics hit the market and canopies could handle much higher wing loadings, manufacturers began moving to elliptical and semi-elliptical wings that were loaded up around 1.5psf (and probably higher nowadays with very experienced canopy flyers). The smallest main canopy on the market when I stopped jumping (years ago) was 77 square feet which is incredibly tiny. [/QUOTE] Thanks. So what I gather is material coatings reduces the airflow through the material, thus increasing the drag per surface area. Combine material improvements (i.e. more drag per area for less weight) with geometry design improvements (airfoils vs round) lead to the performance increases in parachutes. And the eventual design of the “flying squirrel” suits. ---
**Author:** ![Zebra](https://avatars.discourse-cdn.com/v4/letter/z/c0e974/32.png) [@Zebra](https://boards.straightdope.com/u/Zebra)\ **Post date:** [August 22, 2012, 9:22pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/36 "2012-08-22T21:22:27Z")
If you hold 2 corners in each hand the sheet can not expand enough above you. You won’t have enough surface area of the sheet catching the wind. A parachute has a harness and lines so the chute can open to its maxim size. The bed sheet is already too small and if you hold the corners it is much smaller. ---
**Author:** ![Siam\_Sam](https://avatars.discourse-cdn.com/v4/letter/s/d78d45/32.png) [@Siam\_Sam](https://boards.straightdope.com/u/Siam_Sam)\ **Post date:** [August 23, 2012, 3:21am UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/37 "2012-08-23T03:21:23Z")
So, assuming a sheet _would_ work, which thread count(s) would be best? ---
**Author:** ![j\_sum1](https://avatars.discourse-cdn.com/v4/letter/j/8baadc/32.png) [@j\_sum1](https://boards.straightdope.com/u/j_sum1)\ **Post date:** [August 24, 2012, 5:18am UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/38 "2012-08-24T05:18:05Z")
Related question… I have occasionally wondered, if a person had jumped from the twin towers on 911 using a door in a kind of a surfboard fashion, would they have had a reasonable chance of survival? ---
**Author:** ![Lukeinva](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lukeinva/32/17872_2.png) [@Lukeinva](https://boards.straightdope.com/u/Lukeinva)\ **Post date:** [August 24, 2012, 5:31am UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/39 "2012-08-24T05:31:59Z")
> [@Zebra](#): > > If you hold 2 corners in each hand the sheet can not expand enough above you. You won’t have enough surface area of the sheet catching the wind. A parachute has a harness and lines so the chute can open to its maxim size. The bed sheet is already too small and if you hold the corners it is much smaller. I was thinking of tying all four corners together and holding on to the knot. ---
**Author:** ![Valgard](https://avatars.discourse-cdn.com/v4/letter/v/7feea3/32.png) [@Valgard](https://boards.straightdope.com/u/Valgard)\ **Post date:** [August 24, 2012, 3:12pm UTC](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834/40 "2012-08-24T15:12:07Z")
> [@j\_sum1](#): > > Related question… > I have occasionally wondered, if a person had jumped from the twin towers on 911 using a door in a kind of a surfboard fashion, would they have had a reasonable chance of survival? No. However they wouldn’t have had a better chance of survival if they stayed in the building. [Previous page](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834.md?page=1) [Next page](https://boards.straightdope.com/t/is-it-possible-to-parachute-safely-to-earth-from-a-tall-building-using-a-bedsheet/631834.md?page=3)