Physics of turning?

[RippedCord 0]

You're falling in a pancake position with air rushing up equally all around you. What is it that allows a skydiver to execute turn and remain in the pancake position? Is a "swimming" effect, or is it more of a Bernoulli's principle type thing?

AMDG

[Hooknswoop 19]

This is how I explain it:

A bit of Zen philosophy. Picture a tree. The tree has leaves on it. A leaf falls out of the tree. If it is perfectly symmetrical, it will fall straight down (no wind) without turning. Now pick up that leaf and bend an edge of it and drop it. It spins. It is all about defecting air. If you deflect more air to one side than the other and this deflection is not in line with your center of gravity, then you turn. If you deflect more air to one side than the other and this deflection is in line with your center of gravity you side-slide. Put your hand out the window of a moving car and deflect the relative wind in different ways and see the resuls.

Hook

[wmw999 2,291]

I'm more a propeller thinker. In pancake position, you're stable. Lift a leg and the opposite arm, and you're a propeller.

Wendy W.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[fundgh 0]

The pancake has resistance. If you lift or drop or fold part of the pancake, then that part will want to fall faster because there is less resistance. But part of the pancake can not fall faster than the other part, so it is forced to turn around the part that does not want to fall faster (the unfolded part of the pancake).

...FUN FOR ALL!

[Meadman 0]

Here is something I came up with to try and remember how to use my legs.


I try to visualize turning a wheel on the floor with my feet:

To turn clockwise, your right foot moves back and you left foot forward, counter clockwise is just the opposite. As the rushing air is deflected off to one side, that part of your body directing the air moves away from it.

Its real hard to feel this for the first few seconds after exit because the rushing air that powers your movement is from in front of you. Gradually as you slow down forward motion, gravity is steadly increasing your fall and that becomes your engine.

Throw a paper airplane from your roof, for awhile it sails forward, but eventually it slows and falls stable toward the ground, until this happens im usually still a bit stupified so i just Stick it Out! and hold out the best leap of faith my body can muster, until finally reaching the all mighty "Pancake Position"

Wooohoooo

[nightjumps 1]

Hook,

Every once in awhile I have to have some fun at the student's expense. When they ask me that question, I respond, 'I just think "turn" and it happens,' and watch their expression. It looks something like....

[sundevil777 98]

There are so many ways of turning.

I believe that many of the previous posts are not so helpful because, in part, many are not particularly aware of how they actually turn. What I think everyone wants is to be able to rotate in place without any translation.

Pushing your feet out (fore-aft) asymetrically will cause a rotation, but with a large amount of translation with it.

Here is what I do, at least I think I do. I came upon this method after I concluded that I wasn't sure how I did turns during the 'heat' of real RW situations, and by watching video of the world champions of many years ago.

Using your lower legs (knee to foot) like a rudder by moving them sideways will cause you to rotate with little translation. The booties on RW suits are particularly effective for pushing against the air in this way. A slight shoulder dip along with the lower leg 'rudder' can make a rotation with little to no translation.

If others think I am way off base, let's hear your method.

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

[Hooknswoop 19]

An upper body turn will cause the center point of the turn to be near your knees.

A lower body turn (legs or knees) will cause the center of the turn to be around the head.

A center turn is from using both the lower and upper body, as WMW described. Dropping a knee and the opposite shoulder in proportion to the knee produces a quick center turn.

Hook

[sundevil777 98]

There are lots of ways to turn, but I think that the extra 'power' of booties are a good idea for more than just forward drive and extra overall lift. I think they are intended to use like rudders as I described.

If you can get your body to rotate about something other than your center of gravity, that really is a trick. Your center of gravity may move around in space as you rotate (translate)

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

[sundevil777 98]

Actually, of course, you can rotate about something other than your C.G. It just takes more than one type of input in order to do it, that was the point I meant to make.

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

[weid14 0]

Quote

There are so many ways of turning.

I believe that many of the previous posts are not so helpful because, in part, many are not particularly aware of how they actually turn. What I think everyone wants is to be able to rotate in place without any translation.

Pushing your feet out (fore-aft) asymetrically will cause a rotation, but with a large amount of translation with it.

Here is what I do, at least I think I do. I came upon this method after I concluded that I wasn't sure how I did turns during the 'heat' of real RW situations, and by watching video of the world champions of many years ago.

Using your lower legs (knee to foot) like a rudder by moving them sideways will cause you to rotate with little translation. The booties on RW suits are particularly effective for pushing against the air in this way. A slight shoulder dip along with the lower leg 'rudder' can make a rotation with little to no translation.

If others think I am way off base, let's hear your method.

I would not recommend a shoulder dip, you should use your arms, not your shoulder in the upper body part of the turn (knee dopping out and down is the lower body part)

[kallend 1,799]

Physics: Newton's 3rd Law. Deflect air one way, the air exerts a force on you in the opposite direction.

Contrary to what everyone asserts, you always rotate about your center of gravity. If the forces developed by your upper and lower body (legs) are equal and opposite, there is no lateral movement, just rotation - this is called a "center point turn". If the forces are unbalanced you translate as well. The combined translation and rotation is often (and incorrectly) described as a rotation about some point other than your center of gravity.

...

The only sure way to survive a canopy collision is not to have one.