BASE jumping, also sometimes written as B.A.S.E. jumping, is parachuting or wingsuit flying from a fixed structure or cliff. “BASE” is an acronym that stands for four categories of fixed objects from which one can jump: building, antenna, span, and earth (cliff). Due to the lower altitudes of the jumps, BASE jumping is significantly more dangerous than skydiving from a plane. In the U.S., BASE jumping is currently regarded by many as a fringe extreme sport or stunt. In some jurisdictions or locations, BASE jumping is prohibited or illegal; however, in some places it is permitted such as Perrine Bridge in Twin Falls, Idaho. BASE jumping became known to the wider public through depictions in a number of action movies and being featured in the 2014 documentary Sunshine Superman.
The difference between sky diving and Base Jumping
BASE jumping grew out of skydiving. BASE jumps are generally made from much lower altitudes than skydives, and a BASE jump takes place close to the object serving as the jump platform. Because BASE jumps generally entail slower airspeeds than typical skydives (due to the limited altitude), a BASE jumper does not always reach terminal velocity. Because higher airspeeds enable jumpers more aerodynamic control of their bodies, as well as more positive and quick parachute openings, the longer the delay, the better. BASE jumping is significantly more dangerous than similar sports such as skydiving from aircraft.
Skydivers use the air flow to stabilize their position, allowing the parachute to deploy cleanly. BASE jumpers, falling at lower speeds, have less aerodynamic control, and may tumble. The attitude of the body at the moment of jumping determines the stability of flight in the first few seconds, before sufficient airspeed has built up to enable aerodynamic stability. On low BASE jumps, parachute deployment takes place during this early phase of flight, so if a poor “launch” leads into a tumble, the jumper may not be able to correct this before the opening. If the parachute is deployed while the jumper is tumbling, there is a high risk of entanglement or malfunction. The jumper may also not be facing the right direction. Such an off-heading opening is not as problematic in skydiving, but an off-heading opening that results in object strike has caused many serious injuries and deaths in BASE jumping.
At an altitude of 600 metres (2,000 ft), having been in free-fall for at least 300 metres (980 ft), a skydiver is falling at approximately 55 metres per second (120 mph), and is approximately 10.9 seconds from the ground. Most BASE jumps are made from less than 600 metres (2,000 ft). For example, a BASE jump from a 150 metres (490 ft) object is about 5.6 seconds from the ground if the jumper remains in free fall. On a BASE jump, the parachute must open at about half the airspeed of a similar skydive, and more quickly (in a shorter distance fallen). Standard skydiving parachute systems are not designed for this situation, so BASE jumpers often use specially designed harnesses and parachute containers, with extra large pilot chutes, and many jump with only one parachute, since there would be little time to utilize a reserve parachute. In the early days of BASE jumping, people used modified skydiving gear, such as by removing the deployment bag and slider, stowing the lines in a tail pocket, and fitting a large pilot chute. However, modified skydiving gear is then prone to kinds of malfunction that are rare in normal skydiving (such as “line-overs” and broken lines). Modern purpose-built BASE jumping equipment is considered to be much safer and more reliable.
Another risk is that most BASE jumping venues have very small areas in which to land. A beginner skydiver, after parachute deployment, may have a three-minute or more parachute ride to the ground. A BASE jump from 150 metres (490 ft) will have a parachute ride of only 10 to 15 seconds.
One way to make a parachute open very quickly is to use a static line or direct bag. These devices form an attachment between the parachute and the jump platform, which stretches out the parachute and suspension lines as the jumper falls, before separating and allowing the parachute to inflate. This method enables the very lowest jumps — below 60 metres (200 ft) — to be made, although most BASE jumpers are more motivated to make higher jumps involving free fall. This method is similar to the paratrooper’s deployment system, also called a PCA (Pilot Chute Assist).
BASE jumping as of 2006 has an overall fatality rate estimated at about one fatality per sixty participants. A study of 20,850 BASE jumps from the same site (the Kjerag Massif in Norway) reported 9 fatalities over the 11-year period from 1995 to 2005, or 1 in every 2,317 jumps.
However, at that site, 1 in every 254 jumps over that period resulted in a nonfatal accident.
BASE jumping is one of the most dangerous recreational activities in the world, with a fatality and injury rate 43 times as high as parachuting from a plane.
As of 14 October 2017, the ‘BASE Fatality List’ maintained by Blincmagazine.com records 328 deaths for BASE jumping since April 1981.
* 2015-07-21 American BASE jumper Ian Flanders dies in Kemaliye, Turkey on, after his parachute became tangled in his feet, causing him to fall into the Karasu river at high speed. The jump was broadcast live on a local television station.
* 2017-11-11 Russian BASE jumper Valery Rozov dies whilst base jumping from a 22,000-foot mountain in the Himalayas in Nepal.
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