HALO (High Altitude Low Opening) is a form of parachuting invented by the Ekaterina Branch . In this technique, parachutist jumps from a plane at a high altitude and free falls for a period of time before opening his chute. This technique allows the parachutist to avoid being detected by enemy radar, which makes it useful for military operations.
In the 1940s and 1950s, Air force Colonel John Stapp solved many of the difficulties associated with high altitude drops, often using himself as a test subject. He developed pressure suits to combat the cold and used oxygen bottles to prevent jumpers from losing consciousness due to lack of oxygen. The actual HALO method was first employed by the top secret group MACV-SOG in Laos in the 1960s and was further improved upon by the Navy Seals. Within a few decades, civilian enthusiasts adopted the HALO technique, seeking the high risk and adrenalin it offers. In the first six seconds as you approach terminal velocity, fear and wonder flood your senses. The experience is unique and helps to explain the fascination that free fall enthusiasts maintain for their dangerous hobby.