The Skydiving Handbook - Chapter 3 (Flying Your Body)By Bryan Burke on 2011-09-21
The principles of freefall flight are quite simple; after all, you are dealing with just two things: your airfoil (body) and the wind. In a perfect, relaxed arch, or box man, you will fall straight down at a constant rate. To an observer falling along side, you appear stationary. You only seem to be falling relative to someone not in freefall, such as an observer in the airplane or on the ground.
The box man is the neutral freefall position from which all maneuvers are carried out. Relative to a stationary observer, by altering your body position you can turn in place, move up and down, backwards and forwards, or sideways. You can even turn upside down or fly standing up. In fact, no one really knows the limits of body flying yet!
From the box position you can easily initiate turns, forward, backward, and sideways movement, and changes in fall rate. From the side, the body presents a continuous smooth curve to the wind. The head is up, the arms higher thanthe body, and the legs are bent at a 45-degree angle, leaving the lower leg slightly extended into the wind.
From above, the elbows are straight out from the shoulders and the hands are at least as far out as the elbows. The knees are slightly spead so that the feet are as wide apart as the elbows.
Seen from the front, there is a smooth curve from side to side with the hips at the lowest point. Note that head, shoulders, and knees are all held high relative to the hips and chest.
The basic moves are well understood. The most commonly used maneuvers are turns, forward and backward movement, and faster or slower falling. All are accomplished by changing the flow of air around your body. If you think of your box man as being balanced on his center in a neutral position, all he has to do to turn left is deflect more air off his right arm than his left. This is done by simply banking like an airplane - left arm down slightly, right arm up in proportion. The turn will continue until he resumes the neutral position. Lowering one knee relative to the other accomplishes the same thing. That's why an unintentional turn can often be stopped by assuming a neutral position and then giving a little "legs out" to increase awareness and balance the legs.
Turns are also based on deflection of air. In the neutral position, equal amounts of air spill off both sides of the body. To turn right, our box man banks his arms, just as an airplane does in a turn. More air flows off the left side, creating a right turn. Note that the position of the arms relative to each other does not change; both arms tilt as a unit. The rest of the body remains neutral. To stop the turn, simply return to neutral.
Forward motion works on the same principle of deflection. To deflect more air to the rear, resulting in forward motion, bring your arms back a few inches and extend your legs. This tips your body slightly head down, air rushes back off your torso and legs, and you slide forward. The two elements combine to create forward movement. Naturally the opposite motion - arms out and legs in - will make you backslide.
Now think about how to go up and down. Everyone knows that given the same power, a streamlined vehicle can go faster than one that isn't. It slips through the air easier, just as a canoe knifes through the water more easily than a barge. So to speed up, you simply arch more, letting air slip off easily. Flatten out, or lower your knees and elbows, and you will fall slower. Incidentally, the faster you fall the more stable you are because your center of gravity is further below your control surfaces (arms and legs.)
1. If you reverse your arch, what will happen? Is this position stable?
2. Think about forward and backward motion. What would you do to fly sideways?
Proceed to Chapter 4 (The Skydiving Universe)
More articles in this category:
- The Skydiving Handbook - Chapter 2 (Exits) - by Bryan Burke (Posted: 2011-09-21)
- The Skydiving Handbook - Chapter 3 (Flying Your Body) - by Bryan Burke (Posted: 2011-09-21)
- The Skydiving Handbook - Chapter 1 (In the Aircraft) - by Bryan Burke (Posted: 2011-09-21)
- The Skydiving Handbook - by Bryan Burke (Posted: 2011-09-21)
- The Skydiving Handbook - Chapter 8 (After the Landing) - by Bryan Burke (Posted: 2011-09-20)
- The Skydiving Handbook - Chapter 7 (Landings) - by Bryan Burke (Posted: 2011-09-20)
- The Skydiving Handbook - Chapter 6 (Canopy Performance) - by Bryan Burke (Posted: 2011-09-20)
- The Skydiving Handbook - Chapter 5 (After the Freefall) - by Bryan Burke (Posted: 2011-09-20)