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reukkes

Parachute lift speed

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I am planning to tighten myself behind a car with a rope while standing on some sort of skateboard.B|
The rope is attached to one end of the car, and the other end to a kite-surf system on my body, which allows me to unleash the rope by a simple click.
Ofcourse, I will be wearing my unpacked skydive rig.
I want to exercise my flare skills, so I have to reach a height of minimum 10 metres. Now my question: can this be done in theory? How fast do I have to go in horizontal speed to generate lift in my Sabre 150? :SAm I stupid?:S

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sounds pretty dangerous to me... I knew a bunch of folks who have done it with round parachutes, but I would have thought if you get something wrong with your Sabre it's an instant dive into the ground...
[:/]

Sorry, got no idea on speeds needed. Be really careful if you do this - IMO it doesn't feel like a good idea. Stay safe....

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Longer Answer


I have seen a canopy kited with a golfcart (Standing on back of it) on a no wind day. Person never left the ground and it was STILL dangerous.
~D
Where troubles melt like lemon drops Away above the chimney tops That's where you'll find me.
Swooping is taking one last poke at the bear before escaping it's cave - davelepka

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Trying to "parasail" a wing-type parachute is nothing like towing a round behind a car/boat. Chances are that you will end up severely injured or dead. Any practice you could get with your flare would be minimal, and would not apply very well to an actual parachute landing. If this worked, you would see all of the accuracy competitors doing it.

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How fast do I have to go in horizontal speed to generate lift in my Sabre 150?



Effectively you won't - canopies are ground hungry, they're angled down as if they want to fly into the ground. How many times have you been able to actually climb back up during a normal parachute decent?

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This can be done safely ONLY IF YOU GET TRAINING. Winch launch is a common way to launch paragliders in flat areas, but you have to learn some things about how canopies fly under tow. Lockout is the biggest problem; it's an unrecoverable position, and the only way to avoid serious injury when that happens is to disconnect the tow rope.

Here are some places you can get training/info:

http://www.greendragons.co.uk/eppage.htm
http://home.pacifier.com/~ies/TowMe2.html

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Instead of re-inventing the wheel, why not do some research on those who have done it in the past. For one thing, the pitch trim on a towed parachute (round or square) needs to be different from a skydiving canopy. For another, the tow point needs to be located up on risers above the load so that the canopy trim dynamically changes while being towed. ParaFlite worked this out about 20 years ago on a product called BirdWing (IIRC).

Every person I knew who tried to tow an unmodified skydiving canopy either put themselves in the hospital or scared the hell out of themselves.
"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

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What if you wear a rig, get your canopy out, get someone to hold it and let it become fully inflated, and jump off a building? How dangerous (aside from the icky turbulence) would that be?

I know this is done regularly with the bigger canopies off cliffs...

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If you are trying this to practice your flare skills, then you dont have the skills to pull it off. Put the ascender down!

Stick to planes and maybe you wont have to eat through a straw tomorrow.

Johnny
--"This ain't no book club, we're all gonna die!"
Mike Rome

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What if you wear a rig, get your canopy out, get someone to hold it and let it become fully inflated, and jump off a building? How dangerous (aside from the icky turbulence) would that be?

I know this is done regularly with the bigger canopies off cliffs...




If you're an experienced BASE jumper, it's pretty dangerous (and most wouldn't do it except under specific circumstances (distance to obstacles, landing areas, etc.).

If you're not, it's probably suicidal.
7CP#1 | BTR#2 | Payaso en fuego Rodriguez
"I want hot chicks in my boobies!"- McBeth

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A towed canopy is unstable - think of it as trying to balance a ball bearing on tennis ball. If the canopy direction veers slightly to one side the pull from the tow line will try to pull you into a dive. If you react fast enough you can recover but once it goes over if the load is not released you dead.

In paragliding tows you have a release and the operator winching you up can pay out line to prevent the power dive. You wouldnt want to be trying this with less than 200 yards of line. Infact, you wouldnt want to be trying this at all.


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How fast do I have to go in horizontal speed to generate lift in my Sabre 150?



Depends how much you weigh. Not as fast as you would think though as the rope tugging on your harness would pull you forwards and drastically increase the angle of attack of the canopy.

Quote

Am I stupid?



No, as you asked before you tried.

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We did something similar when I was about 13 yrs old. On a windy day we took my brother's Predator 190 onto the golf coarse and got a long rope and all the kids from the neighborhood to pull me up. I had to flare to get lift, then when the rope got to it's full length they would let go and I would practice my "landings" (before I started jumping), amazing what older brothers ( who was jumping at the time) can do to younger brothers.

I was so light in those days with a 190, needless to say nobody else could get off the ground. I wouldn't recommend it with a car. You are probably going to have to travel quite fast to get airborn. Faster than the natural forward speed of your canopy. It would be a totaly unnatural situation, and wouldn't even resemble a landing. It won't be practice at all.

We did something similar a couple of years later on the beach, where we tied a rope around a tree and to the chest strap, on a very windy day. We could fly like a kite. Needless to say this had some disastrous effects. First the rope broke and my friend had to land backwards in a 25 knot wind.

If it wasn't for the beach he would have broken every bone in his body. Then I landed in a tree because of a sudden wind change.

Was funny at the time, but I realize we were lucky to walk away from it.


Whatever the mind can conceive and believe, will be true!

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