Is it possible to parachute safely to earth from a tall building using a bedsheet?

[Dickie.and.his.cat]

I mean by holding two corners of the sheet in either hand.

[Siam Sam]

No.

[aceplace57]

Mythbusters tried it with plywood. iirc they couldn't hold on.

I'm pretty sure a sheet would have the same problem. Can't hold on.
http://mythbustersresults.com/episode38

After testing the speed of updrafts with a special rig on Tory’s truck it was proven that you could not hold on to the piece of plywood if you were in free fall. A mere 45mph gust knocked it out of Tory’s hands; updrafts from skyscrapers reach upwards of 90mph.

[aceplace57]

OTHO Mythbusters did prove a sheet can be used as a rope.

http://mythbustersresults.com/motorcycle-flip

While escaping prison, you could climb down a wall using a rope made of bedsheets.

confirmed

Grant found that making his bedsheet rope was very easy and quick in comparison to the toilet paper and hair ropes. During the test, the rope held Grant’s weight and he successfully descended to the ground.

[JohnT]

Originally Posted by Dickie.and.his.cat

I mean by holding two corners of the sheet in either hand.

In my brothers experience, this results in broken bones.

It is said God protects drunks and little kids, but I think he made an exception in my brothers case (he was 8).

[Dr. Strangelove]

Originally Posted by aceplace57

Mythbusters tried it with plywood. iirc they couldn't hold on.

I'm pretty sure a sheet would have the same problem. Can't hold on.
http://mythbustersresults.com/episode38

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.

That said:
- Your terminal velocity is still probably way too high to come out alive, let alone unscathed.
- A sustained 90 mph gust is probably enough to accelerate you upwards--in which case you have different problems.

[Tom Tildrum]

Superman and Jimmy Olsen used S's cape as a parachute in Kandor one time, but the atmosphere there is denser.

[Airman Doors, USAF]

Originally Posted by JohnT

In my brothers experience, this results in broken bones.

It is said God protects drunks and little kids, but I think he made an exception in my brothers case (he was 8).

He did protect your brother. He went to the doctor, not the coroner.

[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.

[digs]

Originally Posted by 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.

Okay!

We'll wait right here.


(Unfortunately, God seems much more interested in "teaching me a lesson" than in any kind of "protecting"...)

[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.

[Leo Bloom]

Originally Posted by Fubaya

Most parachutes for an average adult* need to 100-200 square feet.....

How did you arrive at this figure?

[Guinastasia]

Why don't you try it and then come back and tell us the results?

[clairobscur]

Originally Posted by aceplace57

OTHO Mythbusters did prove a sheet can be used as a rope.

I knew that. I used to organize live action role-playing game. In one of those, that was taking place in a small castle, some players who had been jailed in a tower did exactly that

One of them came to the "organization room" to tell us, so that we wouldn't be surprised. We immediatly went there, and sure enough another was climbing down the tower with tied sheets We left those remaining going out by the door, telling them they all had successfully escaped by the window.

What the need for Mythbusters when you have Darwin awards candidates willing to test it for real?

[aldiboronti]

I'm sure an umbrella would work.

Oh, wait a minute .......

Online news provider The Saudi Gazette reported on Wednesday that a housemaid jumped from the window of her employer’s unit on the 7th floor of a building.

The report said the victim used an umbrella as parachute to escape. The victim fell on the pavement and died.

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.

[zoid]

Originally Posted by aldiboronti

I'm sure an umbrella would work.

Oh, wait a minute .......



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 know this outs me as a horrible person but that made me laugh.

[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.

[Frylock]

Originally Posted by 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.

If the updraft varies, then you will be accelerated upwards when the rate of updraft increases.

[Dickie.and.his.cat]

As a kid and probably only about 7 stone in weight I tried jumping off the garage roof holding on to a really big fishing umbrella (much bigger than a golf umbrella). I was really surprised how little drag it produced and I hit the floor with a resounding thud. I'm not sure if this adds to the coversation, probably not!

[aldiboronti]

Originally Posted by zoid

I know this outs me as a horrible person but that made me laugh.

Me too. That afterthought of a final sentence in my post was pure guilt.

[Mangetout]

Originally Posted by 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.

[cochrane]

Originally Posted by 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

Originally Posted by 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.

[Mangetout]

Originally Posted by 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.

[Hail Ants]

Originally Posted by 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...

[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.

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.

[Siam Sam]

Originally Posted by aldiboronti

I'm sure an umbrella would work.

Oh, wait a minute .......



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.

[Dickie.and.his.cat]

Originally Posted by 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.

[clairobscur]

Originally Posted by aldiboronti

I'm sure an umbrella would work.
.

Tested that as a kid. Doesn't work.

[simster]

Originally Posted by 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 -

[Jake]

Originally Posted by 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!

[Valgard]

Originally Posted by 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.

[Leaffan]

Originally Posted by 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.

[Kenm]

Originally Posted by 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.

[gnoitall]

Originally Posted by aldiboronti

I'm sure an umbrella would work.

Oh, wait a minute .......



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.

Yeah, it's insensitive, but I couldn't possibly be the only one who thought of it.

[Irishman]

Originally Posted by 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.

Originally Posted by 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.

Originally Posted by 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.

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.

[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.

[Siam Sam]

So, assuming a sheet would work, which thread count(s) would be best?

[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?

[Lukeinva]

Originally Posted by 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.

[Valgard]

Originally Posted by 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.

[MacdaddyC]

Need answer fast?

[Rachellelogram]

I know it still wouldn't work, but I think it would be better to knot the sheet under an armpit (or 2 corners under both armpits?) than under the crotch.

[Siam Sam]

Related question: If you're in a car or even house that is hurtling off a cliff, can you open the door and just step out a fraction of a second before impact?

[Irishman]

Originally Posted by j_sum1

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?

First off, being on top of the door instead of trying to hang on to it from underneath is marginally more effective. Mythbusters demonstrated that the grip factor would make holding on impossible. However, you'd almost immediately get some gust or instability and flip, and thereby be hanging under the door instead of surfing.

Even assuming a magical day, and you somehow stayed on top all the way down, and the board stayed level and didn't tip over, there's still not enough surface area to do much. Your terminal velocity will be a bit lower than ~200 mph for nominal human, spread wide, but not slow enough to prevent severe damage on impact.

[Irishman]

Now the question about bedsheets gets interesting if you propose that you have several sheets available. Could you jury rig a makeshift parachute by tying sheet corners together, then tying the end corners to a piece of rope, and, say, holding the rope under your arms? How many sheets would that take? 4 King size sheets? 12?

[cochrane]

Originally Posted by Siam Sam

Related question: If you're in a car or even house that is hurtling off a cliff, can you open the door and just step out a fraction of a second before impact?

Yes, but it would still kill you. This would be similar to being in a falling elevator and jumping into the air just before it hits the ground. You could not shed enough of your acceleration.

The Mythbusters tested the elevator theory by dropping an elevator in an abonded building eight stories with a dummy inside. The dummy was rigged so that it would be launched in the air a fraction of a second before the elevator hit the ground. They determined the elevator fell at a rate of 53 mph. The dummy was launched into the air at 2 mph. The dummy hit the ground at an effective speed of 51 mph. The dummy was destroyed. They used instruments to determine that the acceleration force of the dummy would have been fatal to a human being.

[TriPolar]

Originally Posted by Irishman

Now the question about bedsheets gets interesting if you propose that you have several sheets available. Could you jury rig a makeshift parachute by tying sheet corners together, then tying the end corners to a piece of rope, and, say, holding the rope under your arms? How many sheets would that take? 4 King size sheets? 12?

If you had rope for lines, and could connect the sheet in between the corners also, you should be in pretty good shape. You could make something that has around the same area of common parachutes, and you have lines for more points of attachment and something better to hold you and the chute together. Unless you stitched the sheets together you'll be venting more air through than a normal parachute, but it should be able to slow your descent sufficiently to live. That is if the sheets don't tear apart. If you have enough rope you could stitch a net together that goes over the top of the chute to distribute your weight better. So if you have four king size bed sheets, 300 - 400 feet of rope, a small knife to cut rope and make holes for stitching, a lot of time to construct the parachute before you are burned alive or shot by your arch enemy, not too many pointy things on the ground, fairly calm air, and a lot of luck, then you could parachute off the building and land safely, or maybe with a couple of minor fractures. Definitely not a splat though. Of course if you have enough time to prepare, you could just go and buy a parachute and use that. Or just not jump off a tall building, which is the simplest solution.

[TriPolar]

ETA: previous post: You might get 30 sq.ft. of effective area from a king size bedsheet, so 4 sheets would only handle a person who weighed 120 pounds. Experienced base jumpers do it with less than 1 sq.ft. per pound, but you don't have a real parachute and probably aren't an experienced base jumper (and if you were you'd never go the top of a tall building without your chute), so 1 sq.ft. per pound is probably the limit before you die.

[Irishman]

Yeah, if you have a lot of time to make an elaborate construction, you might have time to try other methods. That's why I limited the construction to tying corners together. I figure rope from the four outer corners gives you the most useful surface area, as tying ends together both takes up material in the knots, and reduces effectiveness by bunching the sheet ends inward. Rope allows to let the sides out as much as possible. But constructing a net or a harness would be too labor intensive.

I was just trying to back of envelope get a scale of what it would take. So 6 king sheets might get somewhere close, but you're relying on your knot skills and having some rope to allow as much spread as possible. Tying the outer corners to hold onto is going to significantly reduce effectiveness, but how much?

"Well, see, if you have 10 king size sheets and tie all the corners together...."

Um, yeah.

[Czarcasm]

Y'know, if the first response to the OP had been "Yes" we wouldn't be having this conversation.