The Wind Tunnel

The Technology Behind Indoor Skydiving
A vertical wind tunnel has fans at the top to draw air through the flight chamber and then push it back down the sides through Return Air Towers (RATs).

The air is ‘turned’ from the RATs into the bottom of the tunnel (plenum) and back up toward the flight chamber through an inlet contractor.
The inlet contractor reduces the space the air can travel in, thus compressing and speeding up the air before it re-enters the flight chamber.
The result: a smooth column of air that enables you to fly.