Question 1

What is relative wind in skydiving?

Accepted Answer

Relative wind is the airflow a skydiver experiences during freefall. Because you're accelerating toward the earth, air rushes up at you — from your perspective, the wind always comes from directly below (assuming you're falling straight down). Your body position determines how that wind deflects around and off you, which directly controls your freefall speed, stability, and movement.

Question 2

How does body position affect freefall speed?

Accepted Answer

Freefall speed is determined by the balance between gravity and aerodynamic drag. A belly-to-earth arch presents maximum frontal surface area to the relative wind, generating maximum drag and a slower terminal velocity around 110–130 mph. Head-up freefly positions such as sit fly and stand fly commonly run around 140–180+ mph, while head-down can reach 160–220+ mph. Every position between those extremes falls on that spectrum — the more streamlined the position, the faster the fall.

Question 3

What is terminal velocity in skydiving?

Accepted Answer

Terminal velocity is the speed at which aerodynamic drag exactly equals the gravitational force pulling you down — so you stop accelerating and fall at a constant speed. For a belly-to-earth skydiver in a stable arch, this is roughly 110–125 mph depending on body weight and suit. Terminal velocity is not a fixed number; it changes constantly as body position changes.

Question 4

What is potato chipping in skydiving and how do you fix it?

Accepted Answer

Potato chipping is a pitching oscillation where the head and legs rock up and down repeatedly in freefall, like a potato chip flexing. It happens when the aerodynamic center of pressure is near the center of gravity — usually from a flat, neutral body position with no arch. The fix is to increase the arch: pressing the hips down and forward raises the chest and creates a restoring aerodynamic moment that damps the oscillation.

Question 5

Why do tracking jumpers fall faster than belly flyers?

Accepted Answer

Tracking jumpers can cover significant horizontal ground while still falling fast vertically. The vertical component is often around 110–160 mph, while lateral movement can reach 30–80+ mph depending on body position, suit, and skill. The total speed through the air can be much higher than either number alone. The key difference is the body angle: tracking involves a slight head-low angle and swept-back arms that redirect lift generated by the body into horizontal movement.

Question 6

What is the most stable body position in freefall?

Accepted Answer

A strong stable arch (belly-to-earth with a pronounced lower-back arch, arms wide, legs extended) is the most inherently stable freefall position. The arch keeps the aerodynamic center of pressure well above the center of gravity, creating a powerful restoring force that corrects any pitch or roll disturbance. It is why the stable arch is the first position taught in AFF training.

Question 7

How fast do you fall head-down vs belly-to-earth?

Accepted Answer

A belly-to-earth skydiver in a stable arch typically falls at 110–130 mph. A head-down skydiver commonly falls at 160–220+ mph. That speed difference means head-down flyers and belly flyers experience dramatically different relative altitudes in a mixed group — a head-down flyer will appear to fall away from a belly flyer very quickly.

Question 8

What causes instability in freefall?

Accepted Answer

Instability is caused by the aerodynamic center of pressure being at or below the center of gravity, removing the self-correcting restoring moment. Common causes include: piked hips (hunched lower back), arms too close to the body, a flat body angle with no arch, asymmetric limb positions, or transitioning through an unstable intermediate position (like going from belly to sit). Small perturbations from other jumpers or prop wash can also trigger oscillations in marginal positions.

Skydiving Body Position Aerodynamics Simulator

Freefall Position Guide

Freefall Physics: Common Questions

Run a tighter operation on the ground