- See also: Parachute (disambiguation)
A parachute uses drag to slow something moving in air. It is often an umbrella shaped device on which people or things can float slowly and safely down to the ground from a great height, such as an aircraft.
The word parachute comes from the French words parer meaning to protect and chute meaning fall carefully down making sure you are safe.Drogue parachutes are used to aid horizontal deceleration of a vehicle (a fixed-wing aircraft, or a drag racer), or to provide stability (tandem free-fall, or space shuttle after touchdown).
Parachutes are used in a sport called parachuting. Paratroopers are soldiers who attack by jumping from an airplane.
The word "parachute" comes from "para", meaning "against" or "counter" in Ancient Greek, and "chute", the French word for "fall". Some modern parachutes are classified as semi-rigid wings, which are maneuverable and can make a controlled descent to break on impact with the ground.
The inventor Leonardo Da Vinci believed that one day humans would fly. Most of his inventions were never made. However, later people found notebooks containing drawings of parachutes and decided to build it. Only slightly later, a more sophisticated parachute was sketched by the polymath Leonardo da Vinci in his Codex Atlanticus (fol. 381v) dated to ca. 1485. Here, the scale of the parachute is in a more favorable proportion to the weight of the jumper. Leonardo's canopy was held open by a square wooden frame, which alters the shape of the parachute from conical to pyramidal. It is not known whether the Italian inventor was influenced by the earlier design, but he may have learnt about the idea through the intensive oral communication among artist-engineers of the time. The feasibility of Leonardo's pyramidal design was successfully tested in 2000 by the British Adrian Nicholas and again in 2008 by another skydiver. According to the historian of technology Lynn White, these conical and pyramidal designs, much more elaborate than early artistic jumps with rigid parasols in Asia, mark the origin of "the parachute as we know it".
The oldest known depiction of a parachute, by an anonymous author (Italy, 1470s)
Failure[change | change source]
A parachute is carefully folded, or "packed" to ensure that it will open reliably. If a parachute is not packed properly it can result in death because the main parachute might fail to deploy correctly or fully. In the U.S. and many developed countries, emergency and reserve parachutes are packed by "riggers" who must be trained and certified according to legal standards. Sport skydivers are always trained to pack their own primary "main" parachutes.
Parachutes can malfunction in several ways. Malfunctions can range from minor problems that can be corrected in-flight and still be landed, to catastrophic malfunctions that require the main parachute to be cut away using a modern 3-ring release system, and the reserve be deployed. Most skydivers also equip themselves with small barometric computers (known as an AAD or automatic activation device like Cypres, FXC or Vigil) that will automatically activate the reserve parachute if the skydiver himself has not deployed a parachute to reduce his rate of descent by a preset altitude.
Exact numbers are difficult to estimate, but approximately one in a thousand sports main parachute openings malfunction, and must be cut away, although some skydivers have many hundreds of jumps and never cut away. Reserve parachutes are packed and deployed differently. They are also designed more conservatively, and are built and tested to more exacting standards, making them more reliable than main parachutes. However, the primary safety advantage of a reserve chute comes from the probability of an unlikely main malfunction being multiplied by the even less likely probability of a reserve malfunction. This yields an even smaller probability of a double malfunction, although the possibility of a main malfunction that cannot be cut away causing a reserve malfunction is a very real risk. In the U.S., the average fatality rate is considered to be about 1 in 80,000 jumps. Most injuries and fatalities in sport skydiving occur under a fully functional main parachute because the skydiver made an error in judgment while flying the canopy—resulting in high-speed impact with the ground, impact with a hazard on the ground that might otherwise have been avoided, or collision with another skydiver under canopy.