Paraglider
The paraglider , also paraglider or paraglider , is an aerial sports device for paragliding or paragliding .
Legal classification
In Germany, paragliders belong to the aircraft class of air sports equipment in terms of aviation law and there are their own rules for paragliders . Paragliders with motor (see paramotor ) are also aerial sports equipment, but they are part of the rules and regulations of microlight aircraft .
In Austria the paraglider is legally equivalent to other aircraft.
In Switzerland , paragliders are aircraft of a special category of hang glider .
history
The first ideas for an aircraft, which is made entirely of textiles were, in 1948 the later NASA - engineer Francis Rogallo in a patent outlined. This describes "fabric tubes open to the front, arranged parallel to each other and blown up by the airstream, forming a wing". Concrete implementations of this idea by Rogallo are not known. It was not until 1991 to 1996 that the use of paragliders for the controlled landing of the return capsules of spacecraft was experimentally investigated in the Spacewedge project .
The single- wing Sailwing by David Barish from 1965 is considered the first real paraglider .
However, today's gliders based due to the history of Gleitsegelfliegens and screen types used therein as well as today in skydiving usual parachutes on the dihedral multicellular parafoil -Fallschirmkonzept of Domina Jalbert . Parachutes and paragliders have since developed so far apart due to aerodynamic and technical adaptations to the special requirements of the respective sport that a parachute is basically just as unsuitable for mountain starts as a paraglider for parachute jumps.
The most recent development in the paragliding sector is speed flying , in which the pilot uses a greatly reduced glider . The higher wing loading causes a higher speed and a more agile glider behavior when turning . Disadvantages are a larger angle of glide and a larger sink rate .
construction
A paraglider consists of a canopy, lines and risers. A harness is also required for paragliding.
1 riser, 2 connection to the harness, 3 connection to the accelerator, 4 pulley system , 5 pulleys, 6 and 7 tension straps
Canopy
The cap, also known as the dome, is an approximately elliptical wing made of nylon fabric, which is woven particularly tear-resistant thanks to the so-called ripstop technology. The fabric is additionally coated to reduce air permeability. The coating also protects the material against mechanical stress and aging caused by UV light .
The canopy consists of an upper and a lower sail and is divided into numerous chambers in the longitudinal direction. The rear side of such a chamber cell is sewn shut, on the front side is the leading edge through which the individual chambers are filled with air when the paraglider is opened. The resulting dynamic pressure stiffens the canopy so that the most optimal wing profile is created, against which an air flow is applied and generates dynamic lift . Chamber cells lying next to one another are connected to one another by openings, the cross ports , and equalize the dynamic pressure within the entire cap. The wider the canopy becomes with decreasing depth (increasing aspect ratio), the more aggressive its flight behavior and the more challenging it is to fly. A high elongation brings with it an increased performance, which is mainly used in competitive sports.
linen
The gallery lines that run down from the underside of the sail in several levels are brought together to form main lines, which in turn are hooked into line locks and connected to the respective left and right webbing. The paraglider is connected to the pilot's harness with carabiners via these straps, also known as risers . The rearmost line level is not permanently connected to the risers, but is brought together separately on both sides to form a brake line that is used for control.
Aramid or Dyneema lines with a core diameter of approx. 0.6 to 2.0 mm are mostly used as suspension lines. Linen made from these synthetic fibers has a high tear resistance despite its small diameter. In most series devices, these line cores are protected from UV light and mechanical stress by a further textile coating. In the case of competition umbrellas, the sheathing is often dispensed with in order to reduce air resistance.
Harness
The harness is a seat that connects the paraglider to the pilot and is therefore not an integral part of the paraglider. The risers that bundle the main lines of the paraglider are hooked into the harness using carabiners. The pilot is strapped to the harness with leg and chest straps. The reserve parachute and the accelerator system are connected to or integrated into the harness. Current harnesses also have protectors to protect the spine and pelvis, which protect the pilot in the event of an accident.
control
The paraglider is controlled by a brake line on the left and right, whose gallery lines ( brake spider ) pull down the trailing edge of the paraglider and thus change the profile similar to a downward swinging aileron : the result is an increase in both lift and drag. In contrast to an aileron, the two brake lines are not coupled here; they can be operated both in the same direction and in opposite directions and thus serve to control around two axes.
The speed of the paraglider is controlled by actuating the brake lines in the same direction in the range between trim speed and stall . This is complemented by the accelerator : a foot-operated mechanism to shorten the front line levels, which reduces the angle of attack of the entire wing and thus enables the speed to be increased beyond the trim speed.
When turning, the brake lines are operated in opposite directions: The increase in resistance causes the glider to rotate around the vertical axis towards the side that is more strongly braked, thus initiating the turn. The "ears" (the vertical ends) of the umbrella largely prevent it from sliding sideways . Due to its centrifugal force, the low center of gravity passively (despite the actually opposing aileron action) ensures the right lateral inclination for a balanced turn. In addition, the pilot can initiate or support the turn by shifting his weight to the side in the harness.
In contrast to fixed-wing aircraft, the paraglider is not actively dynamically stabilized around the longitudinal and transverse axis, but statically thanks to the low center of gravity. On the one hand, this simplifies steering in calm air; on the other hand, such a system tends to build up dangerously around the longitudinal and transverse axis in turbulence, which the paraglider pilot must actively counteract.
Technical specifications
The canopy of single-seat paragliders has a surface area of approx. 20 to 35 m² and a wingspan of 10 to 13 m. Paragliders for tandem flights have an area of up to 43 m².
Paraglider models are offered in several sizes for different weight ranges. The minimum and maximum permissible flight weight is specified by the manufacturer for approved devices. It is between 55 kg for paragliders with a small area and ends at approx. 130 kg for single-seat paragliders, tandem paragliders can lift up to 250 kg in the air. The flight weight takes into account the weight of the pilot (including clothing), harness, paraglider canopy , rescue equipment , pack sack and other items carried. For the equipment, depending on the area of application, about 5–25 kg is to be expected.
When a paraglider is fully loaded, the higher wing loading (kg / m²) is converted into forward speed while the rate of descent increases. The paraglider now shows more dynamic flight behavior, which is reflected in better control behavior, among other things. Control impulses are converted into changes of direction more quickly. This property is particularly desirable in paragliding acro , so that these pilots often fly at the upper end of the weight range or even above the weight limit.
With the minimum weight, this results in a small surface load on the wing. The paraglider has a lower sink rate, but also a lower forward speed and tends to show an unstable trajectory that has to be constantly stabilized by means of control pulses.
Sample testing and classification
Paragliders must be type- tested in Germany and Austria , and their airworthiness must be proven by the competent authority. In Switzerland this is only necessary for paragliders that are used during training and exams. In many other countries this obligation does not exist.
Sample check
In Germany, paragliders usually belong to the non-licensed air sports equipment according to § 11 LuftGerPV , for which a sample test is carried out by a competent body instead of the approval . The manufacturer is responsible for the airworthiness test for air sports equipment that is (only) subject to a type examination according to § 2 Paragraph 2 LuftGerPV . The respective holder of the air sports device has acc. To report deficiencies immediately according to § 14 para. 5 LuftGerPV. According to § 2 No. 1 LFBAG , the Federal Aviation Office has the task of checking and monitoring the tests to determine the traffic safety (airworthiness) of the aviation device according to the test regulations for aviation equipment. If the manufacturer does his job according to § 2 para. 2 LuftGerPV not work properly after, therefore, the Federal Aviation Office of Airworthiness to § 14 LuftBO responsible. The manufacturer carries out a routine test before delivery of the air sports device. In this the manufacturer confirms that the delivered sample corresponds to the tested sample.
As part of the sample test, paragliders are subjected to various stress tests. Furthermore, the gliders are divided into classes, which place different demands on the pilot's ability. Specially trained test pilots force various predefined flight situations and check the glider's reaction to them. This classification of aircraft is only mandatory in a few countries, but has established itself as a device classification in many countries.
Similar to cars , in some countries (e.g. Germany and Austria) paragliders have to be checked at regular intervals. The inspection interval is usually two years and is determined individually by the manufacturer. The aircraft is checked for damage, the air-tightness of the fabric and the length and strength of the lines. Harnesses and rescue equipment are also subject to this inspection obligation.
In Germany, according to the instructions given by the manufacturer, the airworthiness must be checked or checked by the owner or on his behalf. The owner is responsible for the timely and complete execution of the tests ( § 14 LuftGerPV).
Such a test is not mandatory in Switzerland and it is the pilot's sole responsibility to maintain his aircraft. Carrying an emergency parachute and wearing a helmet is also not required by law there.
Classification according to airworthiness requirements (LTF) / EN standard 926-2
To classify paragliders, test pilots flown various flight maneuvers and give them grades from A (easy) to D (challenging). This takes place in both accelerated and non-accelerated flight conditions and with the minimum and maximum load on the wing. The highest grade in each case determines the overall classification. Only category A umbrellas have been permitted for training in Germany and Austria since 2015.
The new classes, which were introduced in 2010, correspond to the European standard EN 926-2E.
- EN / LTF A paraglider with maximum passive safety and extremely forgiving flight behavior. Good resistance to abnormal flight conditions. Suitable for pilots of all training levels.
- EN / LTF B paraglider with good passive safety and forgiving flight behavior. Somewhat resistant to abnormal flight conditions. Suitable for pilots of all training levels. In practice this class is divided into "Low B" and "High B". While gliders at the lower end of this class are definitely suitable as the first device after training, "High B" exhaust the limitations of this class and buy the higher performance with extreme flight behavior that only differs slightly from that of the C-class.
- EN / LTF C paraglider with moderate passive safety and with potentially dynamic reactions to turbulence and pilot errors. Returning to normal flight may require precise pilot intervention. For pilots who have mastered the elimination of abnormal flight conditions, who fly actively and regularly, and who understand the possible consequences of flying with a paraglider with reduced passive safety.
- EN / LTF D paraglider with demanding flight behavior and potentially violent reactions to turbulence and pilot errors. Returning to normal flight requires precise pilot intervention. For pilots who have a lot of practice in eliminating abnormal flight conditions, who fly very actively, who have significant experience in turbulent conditions and who accept the possible consequences of flying with such a paraglider.
The pre-2010 airworthiness requirements are still relevant as these devices continue to be used. For comparison:
- LTF 1 Paragliders suitable for beginners, paragliders with simple, largely forgiving flight behavior.
- LTF 1-2 paragliders with good-natured flight behavior. Most paragliders are designed by the manufacturers for this class. This largest class is divided into two groups that are suitable for training and those that are more sporty.
- LTF 2 paragliders with demanding flight behavior and dynamic reactions to disturbances and pilot errors.
- LTF 2-3 paragliders with very demanding flight behavior and violent reactions to malfunctions and little scope for pilot errors, requires more experience and regular flight practice.
- LTF 3 paragliders with very demanding flight behavior and very violent reactions to disturbances and little scope for pilot errors. For pilots with above-average piloting skills.
Until 2009, the category designation "DHV" was common for the LTF airworthiness requirements, as there was only one test center of the same name for the German-speaking area. From 2008, the test center of the German EAPR GmbH and from 2011 the Swiss company Air Turquoise were added.
Devices of the upper classes (EN / LTF C to D, formerly LTF 2-3, 3) are only recommended for particularly experienced pilots. Competition paragliders fly in the CCC class (CIVL Competition Class) which is outside this system, which assumes adequate piloting skills in the test maneuvers and limits the maximum achievable air speed to 65 km / h.
The classification is based solely on flight safety and not on performance characteristics. It is quite normal that so-called entry-level gliders "destroy" turbulence in the air by damping them, while paragliders of a higher class show hardly any loss of height, but are more prone to collapses. Higher-rated paragliders usually have better performance characteristics such as better planing and higher maximum speed.
Classification according to AFNOR - CEN
An alternative test procedure for paragliders is the AFNOR test (Association française de Normalization). Here paragliders are divided into the classes standard , performance and competition . This certification is similar to the one described above according to EN / LTF. It is particularly common in the French and English-speaking world of aviation.
The AFNOR test was to be replaced by the European CEN standard in the course of 2006 . Responsible training managers from registered flight schools in accordance with Section 33 LuftVZO in Germany occasionally do not accept sample tests from non-accredited type test centers unless a manufacturer's declaration of airworthiness is available in every case. Otherwise, flying an open class would not be legally possible at any time in Germany.
power
speed
A modern paraglider has a speed range of approx. 22 to 55 km / h , with the trim speed, i.e. the speed with the brakes open and usually also the best gliding, between 32 and 40 km / h. By pulling both control lines at the same time, the sail is curved downwards at the trailing edge. This allows the flight speed to be reduced to around 22 to 25 km / h. Paragliders have the lowest sink rate at around 25 to 35 km / h. Pedaling the accelerator reduces the angle of attack of the paraglider, which means that the paraglider can be accelerated by up to 20 km / h. Competition gliders even fly up to 75 km / h when accelerated.
These speeds relate to the surrounding air, the TAS ( true air speed ) . The speed over the ground, the GS ( ground speed ), depends on the air movements such as headwind or tailwind.
Glide performance
The glide performance of modern paragliders of the series class is around 1: 9.5. This means that one meter in height is converted into a 9.5 meter horizontal stretch. Competition gliders achieve a glide ratio of 1:12, but are well behind hang-gliders (up to 1:20 - fixed-wing aircraft) and gliders (up to 1:70). The minimum descent speed is 1.0 m / s, in trim flight it is about 0.3 m / s higher. The length of all lines added together plays a major role in air resistance. The harness and the pilot himself can strongly influence the gliding performance through their volume and their position in relation to the air flow.
The glide performance plays a subordinate role when flying in thermals. In rising air, it does not matter whether you have gained 500 meters after nine or eleven circles. For valley crossings with a headwind or cross-country flights with up and down winds, however, it matters whether you have lost a hundred meters more after a two-kilometer flight or whether you can still connect to the next thermal.
Distances
Flights of over 100 kilometers are not uncommon taking advantage of thermals . Distances of over 500 kilometers have already been flown (see cross-country flying ).
Security & Risks
In some countries such as Germany, Austria and Switzerland it is generally required by law to complete a training course before flying independently. In other countries, such as France, there is no mandatory paragliding license. Paragliding is usually not classified as a risk sport. In order to face dangerous situations, it is important to inform yourself about the weather situation and the characteristics of the flight area. Depending on the weather, certain flight areas are preferable or even avoided. There are also rules to be observed during the flight (e.g. pre-flight rules or behavior in thermals), and certain procedures are specified for safety reasons (e.g. the 5-point check ).
wind
At wind speeds of approx. 30 km / h or more, you can reach the speed of a normal paraglider (not accelerated). An increase in the wind results in a backward flight (relative to the ground).
When wind hits a slope head-on, the air flow is usually deflected upwards. This so-called dynamic updraft can be used to gain altitude. Strong winds can cause strong turbulence, especially near the ground, which is why a minimum distance from the relief is recommended. In the lee of hills, hills or other obstacles, rotors can form, which can lead to turbulence and severe loss of altitude. These areas are to be avoided when paragliding.
costs
New paragliders cost between 1,600 and 4,000 euros, together with the rest of the equipment, around 2,500 to 5,000 euros can be expected. Used paragliders that are still airworthy are traded from around 500 euros, depending on their age and condition.
Regular maintenance
In Germany and Austria, paragliders have to be checked every two years according to strict specifications by the manufacturer or an authorized test center. The line lengths, the air permeability of the cloth, all seams etc. are checked for wear or aging. In other countries (CH / FR) the test is voluntary. A correlation between the compulsory examination and the number of accidents has not been published.
Paragliders are sewn from light fabrics, so they lack the resilience of inflexible aircraft. Damage from contact with vegetation, for example a thorn bush or barbed wire fence, is easily possible. Small cracks are usually repaired with ripstop stickers according to the manufacturer's instructions. In the event of line tears or line damage, however, the corresponding lines must be replaced, as the line length, which is accurate to the millimeter, has a direct impact on the trim and thus directly on flight safety.
literature
- Toni Schlager, paragliding, the practical book for beginners and professionals , Bruckmann Verlag, Munich 2006, ISBN 3-7654-4503-7 (flight practice, theory, cross-country flying, ground handling, winch towing, aviation law D, A, CH)
- Peter Janssen, Karl Slezak, Klaus Tänzler: Paragliding, Theory and Practice , 15th updated edition, Nymphenburger Verlag, Munich 2007, ISBN 978-3-485-01111-2
- Thomas Ulrich, Rasso Knoller, Claudia Frühwirth: paragliding , Steiger Verlag, Augsburg 1999, ISBN 3-89652-166-7
- Carsten Peter, Toni Schlager: Paragliding, from beginner to professional Bruckmann Verlag, Munich 2003, ISBN 3-7654-3834-0 (with flight practice and theory)
- Burkhard Martens: The thermal book for paragliders and hang-gliders , 1st edition 2005, self-published, ISBN 3-00-015761-1
- Burkhard Martens: The route book for paragliders and hang-gliders , 1st edition 2007, self-published, ISBN 978-3-00-020067-0
- Thermik , magazine for paragliders, Thermik Verlag, A-Wels
- free.aero , digital magazine for paraglider and paramotor pilots, publisher voler.info, F-St.Pierre
Web links
- German Aero Club (DAeC) http://www.daec.de/
- German Hang Glider Association (DHV) http://www.dhv.de/
- Swiss Hang Glider Association (SHV) http://www.shv-fsvl.ch/
- Austrian Aero Club (ÖAeC) http://www.aeroclub.at/
Individual evidence
- ↑ DETEC Ordinance on Special Category Aircraft. Retrieved September 25, 2017 .
- ↑ Table with glide ratios (PDF; 35 kB) of paraglider models manufactured between 2005 and 2009
- ↑ The listing of the world record flight of Nevil Hullet at the FAI. (No longer available online.) Archived from the original on December 11, 2015 ; accessed on January 26, 2015 .
- ↑ Instructions for use for standard paraglider repair stickers ( Memento from March 9, 2012 in the Internet Archive )
