What are some common uses of parachutes

Parachute

A Parachute is a technical device that is used to bring a person or an object from a great height to the ground undamaged. To do this, it increases air resistance or creates dynamic lift. Both of these reduce the speed of fall.

Tandem jump with a flat parachute; The slider is located directly above the jumpers

If the screen is saved as a Jump parachute used for the planned dropping of people, in Germany it belongs to the aircraft class of aircraft according to Section 1 (2) No. 8 LuftVG. On the other hand, parachutes, which are used to rescue from an air emergency, are among the Rescue parachutes (also Emergency parachutes).

Parachutes do not count as braking parachutes.

history

material

Suitable materials for parachutes (but also for balloons, hang-gliders, etc.) are stable (as tear-resistant and load-bearing as possible), but at the same time extremely light and thin, as well as tightly woven (therefore as air-impermeable as possible) fabrics made of fibers that can absorb as little moisture as possible.

In Germany and Japan, parachutes were made of silk until after the Second World War or, as in the case of the Kohnke triangular cap, of cotton. In the USA, parachutes were made of nylon from the 1940s onwards, as the raw material silk was scarce due to the war with Japan. Today it is polyamide fabrics; some of them are coated. The particularly tear-resistant ripstop fabrics with a special weaving technique are particularly widespread. All of these fabrics are called parachute silk and are also used for other purposes in similar processing (tent, sails, tracksuit).

Systems

A distinction is made between two parachute systems - round canopy parachutes and surface parachutes. Both systems can be used as a personal, rescue and cargo parachute.

Round canopy parachutes

Looking up into the open canopy of a round-cap parachute of the Bundeswehr (T-10) during a parachute jump
Apollo 15 spacecraft about to splash down - one of the three parachutes did not open, an example of redundancy. The red and white stripes should show a twisting or incomplete unfolding of the screen.[11]

A round canopy system consists of the main canopy with suspension lines and auxiliary parachute, the inner packaging usually as a packing tube and the harness with outer packaging and main straps and canopy separation locks. The system is supplemented by a reserve parachute, usually as a chest reserve.

The older Round cap systems reduce the fall due to their great aerodynamic drag. Its shape resembles a hollow hemisphere that is open at the bottom and the lower edge of which is attached to the suspension lines that are attached to the main risers from which the parachutist or the payload hangs. At the top there is an opening (top opening) through which pent-up air can escape in order to prevent the umbrella from swinging. A normal round canopy parachute sinks vertically and only receives a horizontal component from the wind drift.

Special forms are Triangular parachutes like the Kohnke triangular parachute RZ 36, which among others. when parachutes were used by paratroopers of the Wehrmacht and after the war in sport skydiving, as well as the new square T-11 troop parachute used by US paratroopers.

In the 1960s, the steerable round canopy parachute MC-6 was introduced into the US armed forces.

Special forces used that in the 1970s High-performance round cap systemsPara-Commander that had slots to allow limited forward travel due to the outflowing ram air. The slot openings could be varied and the parachute steered via control lines. The rate of descent was thereby increased at the same time and the landings became harder. This type of parachute enabled a targeted landing approach to a landing circle and was used in sport skydiving until the early 1980s.

Due to the high risk of injury from high sinking speeds and limited control properties, round canopy parachutes are rarely used as civilian personal parachutes and have also been replaced by school parachute canopies during training. In addition to being used in the military for the rapid lowering of paratroopers and loads from low heights (the lowering machine is in the range of action of handguns and light anti-aircraft guns for a long time), they are almost exclusively used as rescue parachutes for paraglider and hang-glider pilots as well as for gliders, in the Aerobatics or used in total rescue systems on microlight and small sport aircraft.

Rescue parachutes require approval and must be regularly repacked and checked by approved personnel (parachute packers). The packing intervals are two to twelve months, depending on the model. The permissible operating time is determined as part of the approval and is usually 15 years in Germany. After use, a reserve parachute must be checked and repacked by approved personnel (parachute packers with separate approval for rescue parachutes). These parachute specialists are called riggers. You will put a seal on the professionally packed reserve parachute, which can be checked by ground staff before the jump. This makes it clear that reserves were always packed by the rigger within the prescribed time interval.

Total rescue systems are compulsory for ultralight aircraft in Germany; they have been used sporadically for light aircraft for some time (e.g. Cirrus SR-22).

Area parachutes (also paragliders)

Modern Surface parachutes reduce sink (fall) mainly through dynamic lift. Their transverse profile corresponds to that of an aircraft wing. The flat screen is open at the front edge and closed at the rear, so that it is filled by the incoming air and stiffens (self-generating profile). Therefore, these screens are also called Ram air parachute or colloquially as mattress or surface designated.

As soon as the forward speed is high enough, there is a current that creates lift in addition to the air resistance. Therefore, wing parachutes do not sink vertically to the ground, but can, due to their glide angle, cover large horizontal distances in some cases. The right and left side of the trailing edge can be pulled down separately from each other by steering lines, thus changing the profile asymmetrically. One can steer through this; you brake by pulling on both steering lines. In the sports sector today, flat parachutes are used almost exclusively.

Flat parachutes are most often made of the nylon fabrics "F-111" and "Zero-P" (zero porosity: no Air permeability, zero fabric) or combinations thereof. The lifespan is shortened by exposure to sunlight and ranges from around 1,000 (F-111) to over 3,000 jumps (Zero-P).

System structure

Modern system of a student parachute - front side
Modern system of a student parachute - back side
Modern system of a student parachute - rear side pin view
Old empty main container for the main parachute. View of the pull cord with the locking pins; Model Kohnke from 1961.
The three-ring system, which is used to separate the main canopy from the jumper with less effort.
Static Line, German pull-up line

Systems for skydiving today essentially consist of the following assemblies:

  • Harness - English also Rig, is about connectors made of stainless steel or so-called soft left connected to the main canopy and reserve parachute lines. It is used to hold and hold the payload (jumper) and as packaging (container) for the parachutes - consisting of a main and reserve container, Pull-up and deployment handle or bridle and hand deploy (auxiliary umbrella), separating handle and reserve handle, main carrying straps with three-ring system,.
  • Main cap (usually made from a nylon fabric with ripstop, more rarely from F-111), which can be separated in an emergency (e.g. opening problems) with the help of a lock system (e.g. three-ring system). At the top of the main canopy, above the front and rear suspension line bundles, there can be auxiliary packing straps for quick and easy packing of the main canopy.
  • Reserve parachute with an auxiliary parachute and a non-attached POD, usually a wing parachute made of F-111 fabric (rarely a round canopy). The reserve parachute is released either manually using a handle or automatically using the Reserve Static Line (RSL) (when removing the main cap) or via an automatic opening device. In contrast to the main parachute, the reserve parachute can no longer be thrown off by the jumper.
  • POD (Parachute Opening D.evice): A small, half-open bag in which the packed parachute lies and which is closed by the suspension lines, which are fastened in loops in S-loops with the help of packing rubbers. Another inner wrap is a Short pack hose. Both can be used on all surface main caps. Also used to be a Diaper, a closure flap that held the lower part of the paraglider main canopy together, and / or in connection therewith a Reefleinethat went around the main cap causing a delay in opening and was pulled down by the opening cap.
  • Auxiliary parachute lanyard (Bridle) connects the auxiliary parachute to the parachute. A built-in rubber device or a kill-line the auxiliary parachute after the main parachute opening to collapse.
  • Auxiliary screen to open the respective cap. One of three different mechanisms is primarily used to trigger the auxiliary parachute:
    • Hand deploy (Throw Out): The auxiliary parachute is stowed in a pocket attached to the harness and is manually pulled into the air flow to open and then released. First he pulls the locking pin out of the main container loop, whereby the container opens and the parachute is pulled out of its packaging by means of the auxiliary parachute connection line.
    • Release handle: The handle is connected to a thin steel cable (often called a rip cord by laypeople), the other end of which is passed through a loop, thus keeping the flaps of the container closed. By pulling the handle, the steel cable is pulled out of the loop, the flaps are released and the auxiliary parachute snaps into the air flow through a tensioned spring.
    • Static Line (for forced release by automatic release): The opening mechanism of the parachute, consisting of a locking loop and, if necessary, an auxiliary parachute, is connected directly to the aircraft using a pull-up cord with a locking pin. After jumping, the container is opened immediately and the auxiliary parachute or the parachute canopy is pulled out of the bag.
  • Suspension lines in a core-sheath construction (core usually made of Kevlar or polyethylene, sheath made of UV-resistant polyester), which represent the connection between the main canopy and the carrying system.
  • Automatic opening device that automatically triggers the reserve parachute (for example, if the jumper is unconscious) if the approach to the ground occurs faster than a predetermined limit at a certain height.

Reserve parachute

Reserve umbrella mounted on the stomach
Reserve container still closed
An opening reserve container

The reserve parachute (also reserve parachute) in parachuting is not considered a rescue parachute, but belongs to the jump parachutes. An incorrect opening of the main canopy while maintaining the safe opening height is therefore not viewed as an immediate shortage of air, but in principle only as a disruption of the normal jump sequence.

With base jumping, due to the low jump heights, there is no need for a reserve parachute, as there is not enough time for it to be activated and effective in the event of a malfunction when opening the main parachute.

The reserve parachute was usually mounted on the stomach when it first appeared. Only later was it placed on the back above the main screen. The release system has evolved over the years. Today the opening process is activated in different ways. The jumper can trigger the opening with an often metal handle on the left chest. In many systems there is also a connecting line between the main parachute and the reserve locking system. If the jumper removes his main canopy, the opening process is initiated with the main canopy flying away. Many jumpers have also installed an automatic opening device which, by cutting through the locking loop, offers a largely independent system of release.

If the jumper is still at a sufficient height, he should remove the main canopy before releasing the reserve. This prevents a knot between the main and reserve parachutes.

The auxiliary parachute, which carries out and opens the bag with the reserve parachute, is pushed outwards by means of a tensioned spring and shot into the air stream. The auxiliary parachute connecting line between the auxiliary parachute and the bag is particularly wide. This allows the jumper to muster enough strength to pull the bag out should the parachute get caught on the jumper. The bag itself is designed as a so-called "freebag". This means that after the reserve parachute is released, the bag no longer has any connection to it and flies away. Even a caught auxiliary parachute can result in correct deployment of the reserve parachute. The loop is a special fabric that has been treated with silicone to make it easier to slide through the grommets of the closure tabs. In addition, modern opening machines are now installed that cut the loop. If the loop gets caught on one side with the loop in a grommet, for example, the automatic opening device can pull the other cut end of the loop through the tabs. The opening machine itself decides independently of the jumper under an appropriate height for the deployment of the reserve umbrella.

Applications

The parachute has three main uses: rescue, sport / hobby and transport.

rescue

If an aircraft is about to crash (see also ejector seat), either each person or the entire aircraft is braked by the open parachute in the event of a fall and thus protected from an impact (see also rescue parachute, overall rescue system).

A young company in Graz is developing automated rescue parachutes for drones that carry expensive cameras.[12][13]

Sport / hobby

The parachute is used for safe landing when skydiving and object jumping. The parachute flight (so-called “paragliding”) is usually less important than the preceding free fall phase.

Paragliders are a further development of the parachute. With a larger area, improved control and an optimized profile, these are suitable for using updrafts and staying in the air for hours like a glider. In contrast to classic parachutes, paragliders are not opened in free fall, but rather pulled up on the ground.

Hang-glider, glider and paraglider pilots carry a rescue parachute with them on their flights, which is used when the aircraft is no longer airworthy.

Modelling

Parachutes are also used in model construction, mostly simple constructions without a replacement parachute. In model construction, for example, rescue parachutes from model rockets and surface parachutes (paragliders) carry remotely controllable propeller-driven models.

Military and transportation

US paratroopers jump over Australia during an exercise.
An auxiliary parachute pulls a pallet out of a Hercules C-130. (The cargo parachutes are on the relief item.)
Aid goods dropped on the opening parachutes

For military use, in order to reach places that are difficult to access by means of parachute jump, paratroopers and special forces are still deployed in automatic jumps from low heights with round canopy parachutes. Since the 1980s, more often with flat parachutes through HAHO jumps when gliding from great heights. Recently, it has also been forced to release, so that there is no need for an elaborate free-fall training. Some special police units (in Germany only the GSG 9 of the Federal Police) use the parachute jump for air transport for tactical use.

Air pollution is carried out by paratroopers, especially for military purposes, in order to deposit equipment and vehicles in enemy territory in addition to soldiers. Inexpensive round canopy parachutes are still traditionally used for material dropping.More recently, however, independently steered load paraglider systems such as the US Joint Precision Airdrop System / Germany Cassidian ParaLander have been used, which are steered autonomously with the wind into the target area via GPS and an on-board computer.

Some aerial bombs dropped by bombers are also hanging on parachutes, such as the Daisy Cutter. In the case of such bombs, the parachute is intended to delay the fall and thus the explosion of the bomb, in order to enable the dropping aircraft to leave the area threatened by the detonation. In this way, bombs can be dropped at low altitudes.

Ignited flares fall back to earth hanging on parachutes so that the battlefield is illuminated for as long as possible.

Some drones, such as B. the Canadair CL-289, land by parachute.

Some hand grenades with a shaped charge, e.g. B. the RKG-3, use a parachute so that the grenade hits the target at a 90 ° angle to maximize the effect of the shaped charge.

In rocket technology, parachutes are used to recover burnt-out rocket stages, payload fairings and space and sample capsules, e.g. B.

Landing on other celestial bodies

Parachutes can also be used outside the earth to reduce the rate of descent, for example when probes land on other planets or moons. To do this, however, there must be an atmosphere with a certain minimum density, such as on Saturn's moon Titan or on Venus. On planets with a low atmospheric density such as Mars, airbags or brake rockets must also be used. Parachutes cannot be used on celestial bodies without an atmosphere, such as the Earth's moon.

See also

literature

  • W.D. Brown: "Parachutes", Sir Isaac Pitman & Sons Ltd., London 1951.
  • W. Gericke: "Parachuting", Tilia Verlag, Wiesbaden 1962.
  • Klaus Heller: "Skydiving for beginners and advanced", Nymphenburger, Munich 1981-2008, ISBN 3-485-01636-5.
  • S. Ruff, M. Ruck, G. Sedelmayr: "Safety and Rescue in Aviation", Bernard & Graefe Verlag, Koblenz 1989, ISBN 3-7637-5293-5.
  • H. Steiner: "The Parachute", Richard Karl Schmidt & Co publishing house, Berlin 1931.

Web links

Individual evidence

  1. abLynn White: "The Invention of the Parachute", in: Technology and Culture, Vol. 9, No. 3 (1968), pp. 462-467 (466)
  2. abLynn White: "The Invention of the Parachute", in: Technology and Culture, Vol. 9, No. 3 (1968), pp. 462-467 (462f.)
  3. abcdLynn White: "The Invention of the Parachute", in: Technology and Culture, Vol. 9, No. 3 (1968), pp. 462-467 (465)
  4. ↑ Lynn White: "The Invention of the Parachute", in: Technology and Culture, Vol. 9, No. 3 (1968), pp. 462-467 (465f.)
  5. ↑ Marc van den Broek: Leonardo da Vinci's inventiveness. A search for clues, Mainz, 2018, ISBN 978-3-961760-45-9, pp. 30–31
  6. ↑ BBC: Da Vinci's Parachute Flies (2000); FoxNews: Swiss Man Safely Uses Leonardo da Vinci Parachute (Memento from April 21, 2010 in Internet Archive) (2008)
  7. ↑ Information that Veranzio himself jumped with his parachute from the Campanile in Venice or from St. Martin's Cathedral in Bratislava at the age of 65 is a modern legend (see the article about Fausto Veranzio for more details).
  8. Pictures-Conversations-Lexicon for the German people. A guide to community knowledge dissemination and entertainment. F. A. Brockhaus, Leipzig 1837 (zeno.org [accessed on June 5, 2019] lexicon entry "Fallschirm").
  9. ↑ Catillon, Marcel: Mémorial aéronautique: qui était qui?. Paris: Nouvelles éditions latines, 1997. ISBN 2-7233-0529-5. P. 147.
  10. One was lovesick. In: The mirror. No.46, 1962, p.110 (online - June 12, 2008, about the parachute manufacturer Richard Kohnke).
  11. ↑ Matthias Kremp: Internet users discover hidden messages in the Mars parachute. In: spiegel.de. February 23, 2021, accessed February 27, 2021.
  12. ↑ Graz developed a parachute for drones orf.at. October 27, 2016. Retrieved October 28, 2016.
  13. ↑ Drone Rescue System sciencepark.at, accessed on October 28, 2016.