Parachute
A parachute is a technical device that is used to bring a person or an object from a great height to the ground intact. To do this, it increases air resistance or creates dynamic lift . Both reduce the speed of fall .
If the parachute is used as a jump parachute for the planned dropping of people, in Germany it belongs to the aircraft class of aircraft in accordance with Section 1 (2) No. 8 LuftVG . Parachutes that are used to rescue from an air emergency , on the other hand, count to the rescue parachutes (also emergency parachutes ).
Brake parachutes are not parachutes.
history
Renaissance
The early history of the parachute goes back to the Renaissance . The oldest draft of a parachute is contained in an anonymous Italian manuscript (British Museum Add. MSS 34,113, fol. 200v) from the 1470s. It shows a conical parachute with a cross-like pole frame held by a man hanging freely in the air. A waist belt, which is connected to the ends of the frame by four straps, is used for safety by the parachutist. This construction can be seen as a step forward compared to another illustration (189v), in which a man tries to slow down the free fall by grasping two long flags of fabric as arm extensions. Although the surface of the parachute is too small to provide effective air resistance and the wooden frame is redundant and even potentially dangerous, the revolutionary new character of the design is evident.
Only a short time later (around 1485) the universal scholar Leonardo da Vinci presented a technically more sophisticated sketch in his Codex Atlanticus (fol. 381v), in which the dimensions of the parachute are more favorable to the weight of the jumper. Leonardo's parachute canopy is held open by a square wooden frame, which changes the shape of the canopy from conical to pyramidal. Whether the Italian inventor was influenced by the earlier parachute design cannot be definitively determined, but the idea might have come to his ears through the intensive exchange of ideas between the artist engineers of the time. The feasibility of Leonardo's pyramidal design was demonstrated by the British Adrian Nicholas in 2000 and by another parachutist in 2008 .
Inspired by Leonardo's drawing, the Croatian scholar Faust Vrancic (1551–1617) designed his own parachute. Vrancic kept the rectangular frame but replaced the parachute canopy with a bulging, sail-like piece of cloth that he rightly assumed would better slow the fall. According to the American engineering historian Lynn White , it is these well thought-out parachute designs, far more complex than early artistic jumps in Asia with stiffened parasols , that are at the beginning of the development of the "parachute as we know it".
Modern
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The Frenchman Louis-Sébastien Lenormand jumped in 1783 in Montpellier with a self-constructed parachute from the tower of the observatory and landed unscathed. This event is considered to be the beginning of the modern parachute and its actual history of development.
On Oct. 3, 1785 was Jean-Pierre Blanchard in Bornheim , a district of Frankfurt , his dog and on August 23, 1786 in Hamburg a sheep from a balloon down from the parachute. The first person to voluntarily parachute out of a balloon was the French André-Jacques Garnerin on October 22, 1797. He jumped from a self-made hydrogen balloon from a height of 400 meters above the Parc Monceau in Paris .
At the end of the 19th century, German aviation pioneer Käthe Paulus invented the collapsible parachute. From 1893 onwards she carried out more than 100 so-called "parachute falls" from over 1000 m height. She is considered to be one of the first women to jump with a parachute.
In 1912 the Russian Gleb Kotelnikow invented the backpack parachute. On March 1, 1912, US Army Captain Albert Berry became the first person to jump off an airplane.
In 1913, the Slovak Štefan Banič developed a functional parachute that can be placed around the body axis according to the umbrella principle, for which he acquired US Patent No. 1108484 in 1914. Since his invention could not find a buyer, Banič donated the patent to the US Army, which probably never used it.
On August 19, 1913 , the Frenchman Adolphe Pégoud was the first pilot in aviation history to parachute out of his Bleriot .
The principle of the double cover and the pull cord attached to the aircraft, as it is still used today, comes from the German airship engineer Otto Heinecke . It allows a safe jump, in which the parachute cannot get caught on the aircraft.
On April 28, 1919, the American Leslie Leroy "Sky High" Irvin jumped for the first time with a manually deployable dorsal parachute that was not attached to the aircraft.
Richard Kohnke set a new record in 1930 with a jump from 7800 meters with a free fall time of 142 seconds. Later he produced rescue parachutes in his parachute factory in Ziegelhausen .
There were a few parachute deployments as early as the First World War. The airborne operations of World War II were then militarily of decisive operational importance. For the parachutes used by the German paratroopers, see Parachutes of the Wehrmacht .
On August 16, 1960, the American Joseph Kittinger jumped with a special parachute from a balloon at a height of 31,330 meters and landed after 9½ minutes. This was the highest skydive in history until 2012.
The skydiving as a hobby became a civilian end of the 1950s slowly to the sport. Many later innovations were developed through sport skydiving. While the military by and large used the round canopy parachute with an automatic pull-up line for mass dropping of soldiers from low jumping heights, also for training reasons, this did not meet the requirements in sport parachuting.
In the field of sports, the freefall time was one of the early sports disciplines, as was the target jump with a short distance to the zero disc. Initially, the civilian jumpers used the available military jump systems with a round canopy as the main parachute, which was packed in a container with a 3-pin lock. The reserve parachutes emerging during this period were mounted on the abdomen and secured with a 2-pin lock. Line throws, a canopy malfunction, were a common problem. Often times, the main parachute had to be separated using the canopy locks attached to the risers.
In order to be able to perform target jumps better, the Para Commander came up in 1963, a controllable high-performance round canopy with propulsion, which was adapted by the US military for small special forces.
The first wing parachutes found their way into sport in the early 1970s . The initial designs were very unreliable. The Para Plane , an early development, did not open correctly on one of three jumps. Nevertheless, the new type of parachute soon revolutionized jumping. In those years the reserve parachute was also put on its back in a compartment above that of the main parachute. There were now manufacturers who primarily produced for civil purposes and their needs. In the mid-1970s, Bill Booth developed the 3-ring system. This innovation made it possible to separate the parachute completely and reliably with a relatively light pull on a handle (separating cushion). In the years that followed, more and more details were changed on the parachute. In particular, the reliability of the materials and opening systems has been further improved. Today, parachute failure is very rare; Today more accidents happen due to daring landing maneuvers (wing parachute) than due to problems with the parachute.
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 were parachutes until after the Second World War from silk or as the Kohnke Triangle cap of cotton . In the USA, parachutes were made of nylon from the 1940s onwards , as silk was scarce due to the war with Japan. Today it is polyamide fabrics; some of them are coated. Especially tear-resistant ripstop fabrics with a special weaving technique are widespread . All 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
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 air resistance . Its shape resembles a hollow hemisphere that is open at the bottom, on the lower edge of which the suspension lines are attached, which are attached to the main risers on which the parachutist or the payload is suspended. 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 .
In the 1960s the steerable round canopy parachute MC-6 was introduced into the US armed forces .
In the 1970s, special forces used the high-performance Para-Commander round canopy system , which had slots to enable forward travel through the ram air flowing out. The slot openings could be varied via control lines and the parachute could be controlled to a limited extent. The rate of descent was thereby increased at the same time and landings became harder. This type of parachute enabled a more targeted approach to a landing circle and was used in sport skydiving until the early 1980s.
Special forms are triangular parachutes such as the Kohnke triangular parachute RZ 36, which u. a. when parachutes were used by the paratroopers of the Wehrmacht and after the war in sport skydiving , as well as the new square parachute T-11 by the US paratroopers.
Due to the high risk of injury due to high sinking speeds and limited control properties, round canopy parachutes are rarely used as civilian parachutes . 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 microlights and small sport aircraft .
Rescue parachutes are subject to approval and have to be repacked and checked regularly 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 a rescue parachute has been used, it must be checked and repacked by approved personnel (parachute packers with special 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 wing 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 as Stauluftgleitfallschirm or colloquially as mattress or area designated.
As soon as the forward speed is high enough, there is a current that creates lift in addition to air resistance. Therefore, wing parachutes do not sink vertically to the ground, but can sometimes cover large horizontal distances due to their glide angle . 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. You can steer through this; you brake by pulling on both steering lines. Flat parachutes are used almost exclusively in sports today.
Flat parachutes are most often made of the nylon fabrics "F-111" and "Zero-P" (zero porosity: no air permeability, zero fabric) or a combination of these. The service life is shortened by exposure to sunlight and ranges from around 1,000 (F-111) to over 3,000 jumps (Zero-P).
System structure
Systems for skydiving today essentially consist of the following assemblies:
- Harness - also known as a rig - is connected to the suspension lines of the main canopy and the reserve parachute via connectors made of stainless steel or so-called soft links. It is used to hold and hold the payload (jumper) and as packaging (container) for the parachutes - consisting of main and reserve container , pull-up and deployment handle or bridle and hand deploy (auxiliary parachute), separating handle and reserve handle, main carrying straps with three- Ring system,.
- Main canopy (usually made of a nylon fabric with ripstop , more rarely of F-111), which can be detached in an emergency (e.g. if there are problems opening) 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 may be auxiliary packing straps for quick and easy packing of the main canopy.
- Reserve parachute with auxiliary parachute and non-attached POD, mostly a wing parachute made of F-111 fabric (rarely a round canopy). The reserve parachute is released either manually via a handle, automatically via the Reserve Static Line (RSL) (when the main canopy is removed) 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 ( P arachute O pening D evice): A small semi-open pocket in which the packed parachute is located and which is closed by the suspension lines which are fixed in S-blows with the aid of rubber bands in loops. Another inner packaging is a short packing tube . Both can be used on all surface main caps. Formerly also a diaper , a closure flap that held the lower part of the paraglider main canopy together, and / or in connection with it a reef line which ran around the main canopy and caused an opening delay and was pulled down by the opening canopy .
- Auxiliary parachute bridle connects the auxiliary parachute to the parachute. To reduce the air resistance, a built-in rubber device or a kill-line causes the auxiliary parachute to collapse after the main parachute opening .
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Auxiliary screen for opening 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 airflow to open and then released. He first 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 through 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 several meters long 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 umbrella (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
The reserve parachute (also reserve parachute) in parachuting is not considered a rescue parachute, but belongs to the jump parachutes. Failure to open the main canopy while maintaining the safe opening height is therefore not regarded as an immediate shortage of air , but in principle only as a disruption of the normal jumping process.
With base jumping , due to the low jump heights, there is no need for a reserve parachute, as there is not enough time for its timely activation and effectiveness 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 wing.
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 if the parachute gets 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 has no 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 other cut end of the loop can pull itself through the tabs through the automatic opening device. 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
Event of an impending crash of an aircraft (see also ejection seat ), either each person individually or the entire aircraft braked by the open parachute during a fall and thus protected from an impact (sa parachute , rescue system ).
A start-up company in Graz is working on the development of automated rescue parachutes for drones that carry expensive cameras.
Sport / hobby
The parachute is used for safe landing when skydiving and object jumping . The parachute flight (so-called "parachute ride") is usually less important than the preceding free flight phase.
Paragliders are a further development of the parachute . With a larger area, improved control and optimized profile, these are suitable for using updrafts and keeping themselves 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
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-cap parachutes . Since the 1980s more often with flat parachutes through HAHO jumps in gliding use from great heights. Recently, it has also been forced to release, so that there is no need for costly free fall training. Some special police units (in Germany only the GSG 9 of the Federal Police ) use the parachute jump to transport air 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 discharge. More recently, however, independently steered load paraglider systems such as the Joint Precision Airdrop System 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 endangered by the detonation. In this way, bombs can be dropped at low altitudes.
In rocket technology, parachutes are used to recover burnt-out rocket stages and payload fairings.
- Cirrus and cumulus missiles,
- Rockets from Berthold Seliger Research and Development Corporation,
- Booster of the Space Shuttle ,
- Falcon 9 payload fairing .
Landing on other celestial bodies
Parachutes can also be used outside of 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 like 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
- WD 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, Berlin 1931.
Web links
Individual evidence
- ↑ a b Lynn White: "The Invention of the Parachute", in: Technology and Culture , Vol. 9, No. 3 (1968), pp. 462-467 (466)
- ↑ a b Lynn White: "The Invention of the Parachute", in: Technology and Culture , Vol. 9, No. 3 (1968), pp. 462-467 (462f.)
- ↑ a b c d Lynn White: "The Invention of the Parachute", in: Technology and Culture , Vol. 9, No. 3 (1968), pp. 462-467 (465)
- ↑ Lynn White: "The Invention of the Parachute", in: Technology and Culture , Vol. 9, No. 3 (1968), pp. 462-467 (465f.)
- ↑ Marc van den Broek : Leonardo da Vinci's ingenuity. A search for traces , Mainz, 2018, ISBN 978-3-961760-45-9 , pp. 30–31
- ↑ BBC: Da Vinci's Parachute Flies (2000); FoxNews: Swiss Man Safely Uses Leonardo da Vinci Parachute ( Memento from April 21, 2010 in the Internet Archive ) (2008)
- ↑ 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 (cf. for more details in the article about Fausto Veranzio).
- ↑ Bilder-Conversations-Lexikon for the German people . A guide to community knowledge dissemination and entertainment. FA Brockhaus , Leipzig 1837 ( zeno.org [accessed on June 5, 2019] lexicon entry “Fallschirm”).
- ^ Catillon, Marcel: Mémorial aéronautique: qui était qui? . Paris: Nouvelles éditions latines, 1997. ISBN 2-7233-0529-5 . P. 147.
- ↑ One was lovesick . In: Der Spiegel . No. 46 , 1962, pp. 110 ( online - June 12, 2008 , via the parachute manufacturer Richard Kohnke).
- ↑ Graz developed a parachute for drones orf.at. October 27, 2016. Retrieved October 28, 2016.
- ↑ Drone Rescue System sciencepark.at, accessed on October 28, 2016.
