Can't or won't jump out of a plane to experience free fall diving, but you would still like to experience this thrill? You can try indoor skydiving which allows you the thrill of skydiving but without the trauma of having to jump out of the door of a plane. All one does is to go into a vertical tunnel and feel the same free fall sensation for about 3 minutes without leaving a plane at 3,000 feet or so. Even though indoor skydiving is ideal for those who don't want to jump out of a plane, it is also used to train skydivers for traditional jumping, when conditions do not allow for a regular jump. This type of skydiving emulates regular skydiving almost perfectly; the only missing sensation is the sideways push you normally feel when you exit a plane. Military training schools and skydiving clubs and groups have been using indoor skydiving in a wind tunnel for additional practice, without having the expense of hiring a plane for the jumps all the time. A parachute is not used in this type of exercise; the pressure of the wind from the tunnel simulates the slowing force of the parachute you would normally have. Plus, the most important feature of the jump is the free fall period, which many people have a fear of. Even those who have no such fear, or have overcome it, like to use these 12X12 tunnels to practice turns and positions before trying them out in the "real world". This is also an ideal way for skydiving teams to perfect their routines and stunts before going live up in the sky. Diving near other skydivers can be a dangerous experience for fear of collision, but timing and distances can be worked out more practically when the danger is removed. The added pressure of when to check the altimeter and open the chute can ruin the concentration on a stunt. Once the stunt is mastered, this becomes less of a problem. It is extremely important to deploy the chute properly during group dives because of fear of entanglement. Better to get the timing down pat before a real dive. Besides for training and to cater to a certain kind of diver, skydiving indoors has been recognized as a sport in its own right, not just substituting for skydiving from a plane. Just as base jumping (jumping from a stationary object) is a new sport that many people enjoy. It is still a thrill to fall against 120mph winds, even if it is not in the sky. Before getting into skydiving, its better going through a . Most jumps in a wind tunnel last about 3 minutes, but require a greater investment in time since you have to don the gear (20 minutes) and get instruction (30 minutes). Outside of true skydiving, this is as close to flying as most people will ever get.