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40-553: The Carat was designed by Technoflug around the wings and horizontal tail of the Schempp-Hirth Discus sailplane , marrying these to a new fuselage , fin , undercarriage and engine.. Structurally the aircraft is a mixture of fibreglass and carbon fibre composites . The wings have PVC foam cores. In plan the wings have parallel chord inner panels and two outer sections of increasing straight taper. Winglets are an option. Schempp-Hirth type airbrakes are mounted on

80-473: A definition similar to "all theropods closer to birds than to Deinonychus ", with Troodon being sometimes added as a second external specifier in case it is closer to birds than to Deinonychus . Avialae is also occasionally defined as an apomorphy-based clade (that is, one based on physical characteristics). Jacques Gauthier , who named Avialae in 1986, re-defined it in 2001 as all dinosaurs that possessed feathered wings used in flapping flight , and

120-442: A group called Paraves . Some basal members of Deinonychosauria, such as Microraptor , have features which may have enabled them to glide or fly. The most basal deinonychosaurs were very small. This evidence raises the possibility that the ancestor of all paravians may have been arboreal , have been able to glide, or both. Unlike Archaeopteryx and the non-avialan feathered dinosaurs, who primarily ate meat, studies suggest that

160-480: A positive angle of attack to deflect air downward. Symmetrical airfoils have higher stalling speeds than cambered airfoils of the same wing area but are used in aerobatic aircraft as they provide the same flight characteristics whether the aircraft is upright or inverted. Another example comes from sailboats, where the sail is a thin sheet. For flight speeds near the speed of sound ( transonic flight ), specific asymmetrical airfoil sections are used to minimize

200-406: A sister group, the order Crocodilia , contain the only living representatives of the reptile clade Archosauria . During the late 1990s, Aves was most commonly defined phylogenetically as all descendants of the most recent common ancestor of modern birds and Archaeopteryx lithographica . However, an earlier definition proposed by Jacques Gauthier gained wide currency in the 21st century, and

240-424: A strong yet lightweight skeleton . Birds live worldwide and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m (9 ft 2 in) common ostrich . There are over 11,000 living species and they are split into 44 orders . More than half are passerine or "perching" birds. Birds have wings whose development varies according to species; the only known groups without wings are

280-411: A suitable angle of attack relative to the flow of air past the wing. When this occurs, the wing deflects the airflow downwards, "turning" the air as it passes the wing. Since the wing exerts a force on the air to change its direction, the air must exert a force on the wing, equal in size but opposite in direction. This force arises from different air pressures that exist on the upper and lower surfaces of

320-717: A time, sometimes for years, and rarely for life. Other species have breeding systems that are polygynous (one male with many females) or, rarely, polyandrous (one female with many males). Birds produce offspring by laying eggs which are fertilised through sexual reproduction . They are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching. Many species of birds are economically important as food for human consumption and raw material in manufacturing, with domesticated and undomesticated birds being important sources of eggs, meat, and feathers. Songbirds , parrots, and other species are popular as pets. Guano (bird excrement)

360-533: Is called ornithology . Birds are feathered theropod dinosaurs and constitute the only known living dinosaurs . Likewise, birds are considered reptiles in the modern cladistic sense of the term, and their closest living relatives are the crocodilians . Birds are descendants of the primitive avialans (whose members include Archaeopteryx ) which first appeared during the Late Jurassic . According to recent estimates, modern birds ( Neornithes ) evolved in

400-429: Is harvested for use as a fertiliser. Birds figure throughout human culture. About 120 to 130 species have become extinct due to human activity since the 17th century, and hundreds more before then. Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them. Recreational birdwatching is an important part of the ecotourism industry. The first classification of birds

440-503: Is not considered a direct ancestor of birds, though it is possibly closely related to the true ancestor. Over 40% of key traits found in modern birds evolved during the 60 million year transition from the earliest bird-line archosaurs to the first maniraptoromorphs , i.e. the first dinosaurs closer to living birds than to Tyrannosaurus rex . The loss of osteoderms otherwise common in archosaurs and acquisition of primitive feathers might have occurred early during this phase. After

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480-462: Is opened by the centrifugal force on the turning blades, working against a folding force provided by a gas damping spring mechanism. This folding mechanism has the advantage of simplicity, but it means that the engine can not be windmill-started if the battery is flat. Because of the forward pointing blades when the engine is off, the Carat cannot be towed aloft like traditional sailplanes. The first flight

520-438: Is powered by an air-cooled, four cylinder, Volkswagen derived, 40 kW (54 hp) Sauer S1800 piston engine. This drives the unique feature of the Carat, its folding two blade propeller : the blades fold forward like spears to minimize drag when the engine is off. This is in contrast to other motorgliders which mostly either store the propeller inside the fuselage, or merely feather the propeller blades. The Carat's propeller

560-516: Is synonymous to Avifilopluma. † Scansoriopterygidae † Eosinopteryx † Jinfengopteryx † Aurornis † Dromaeosauridae † Troodontidae Avialae Based on fossil and biological evidence, most scientists accept that birds are a specialised subgroup of theropod dinosaurs and, more specifically, members of Maniraptora , a group of theropods which includes dromaeosaurids and oviraptorosaurs , among others. As scientists have discovered more theropods closely related to birds,

600-472: Is the study of wing performance in air. Equivalent foils that move through water are found on hydrofoil power vessels and foiling sailboats that lift out of the water and on submarines that use diving planes to point the boat upwards or downwards, while submerged. Hydrodynamics is the study of foil performance in water. The word "wing" from the Old Norse vængr for many centuries referred mainly to

640-530: Is used by many scientists including adherents to the PhyloCode . Gauthier defined Aves to include only the crown group of the set of modern birds. This was done by excluding most groups known only from fossils , and assigning them, instead, to the broader group Avialae, on the principle that a clade based on extant species should be limited to those extant species and their closest extinct relatives. Gauthier and de Queiroz identified four different definitions for

680-715: The Late Cretaceous and diversified dramatically around the time of the Cretaceous–Paleogene extinction event 66 million years ago, which killed off the pterosaurs and all non- ornithuran dinosaurs. Many social species preserve knowledge across generations ( culture ). Birds are social, communicating with visual signals, calls, and songs , and participating in such behaviour as cooperative breeding and hunting, flocking , and mobbing of predators. The vast majority of bird species are socially (but not necessarily sexually) monogamous , usually for one breeding season at

720-660: The Tiaojishan Formation of China, which has been dated to the late Jurassic period ( Oxfordian stage), about 160 million years ago. The avialan species from this time period include Anchiornis huxleyi , Xiaotingia zhengi , and Aurornis xui . The well-known probable early avialan, Archaeopteryx , dates from slightly later Jurassic rocks (about 155 million years old) from Germany . Many of these early avialans shared unusual anatomical features that may be ancestral to modern birds but were later lost during bird evolution. These features include enlarged claws on

760-479: The World's Aircraft 2011/12 General characteristics Performance Wing A wing is a type of fin that produces both lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform. Wing efficiency is expressed as lift-to-drag ratio , which compares the benefit of lift with the air resistance of a given wing shape, as it flies. Aerodynamics

800-428: The appearance of Maniraptoromorpha, the next 40 million years marked a continuous reduction of body size and the accumulation of neotenic (juvenile-like) characteristics. Hypercarnivory became increasingly less common while braincases enlarged and forelimbs became longer. The integument evolved into complex, pennaceous feathers . The oldest known paravian (and probably the earliest avialan) fossils come from

840-509: The birds that descended from them. Despite being currently one of the most widely used, the crown-group definition of Aves has been criticised by some researchers. Lee and Spencer (1997) argued that, contrary to what Gauthier defended, this definition would not increase the stability of the clade and the exact content of Aves will always be uncertain because any defined clade (either crown or not) will have few synapomorphies distinguishing it from its closest relatives. Their alternative definition

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880-665: The earliest members of Aves, is removed from this group, becoming a non-avian dinosaur instead. These proposals have been adopted by many researchers in the field of palaeontology and bird evolution , though the exact definitions applied have been inconsistent. Avialae, initially proposed to replace the traditional fossil content of Aves, is often used synonymously with the vernacular term "bird" by these researchers. † Coelurus † Ornitholestes † Ornithomimosauria † Alvarezsauridae † Oviraptorosauria   Paraves Most researchers define Avialae as branch-based clade, though definitions vary. Many authors have used

920-483: The extinct moa and elephant birds . Wings, which are modified forelimbs , gave birds the ability to fly, although further evolution has led to the loss of flight in some birds , including ratites , penguins , and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds , have further evolved for swimming. The study of birds

960-451: The first avialans were omnivores . The Late Jurassic Archaeopteryx is well known as one of the first transitional fossils to be found, and it provided support for the theory of evolution in the late 19th century. Archaeopteryx was the first fossil to display both clearly traditional reptilian characteristics—teeth, clawed fingers, and a long, lizard-like tail—as well as wings with flight feathers similar to those of modern birds. It

1000-693: The foremost limbs of birds (in addition to the architectural aisle). But in recent centuries the word's meaning has extended to include lift producing appendages of insects , bats , pterosaurs , boomerangs , some sail boats and aircraft , or the airfoil on a race car . In nature wings have evolved in dinosaurs, birds , mammals, fish, reptiles and plants as means of locomotion . Various species of penguins and other flighted or flightless water birds such as auks , cormorants , guillemots , shearwaters , eider and scoter ducks and diving petrels are efficient underwater swimmers, and use their wings to propel through water. The design and analysis of

1040-427: The fully limp flexible wing. Domina Jalbert invented flexible un-sparred ram-air airfoiled thick wings. Natural world: Aviation: Sailing: Bird Birds are a group of warm-blooded vertebrates constituting the class Aves ( Latin: [ˈaveːs] ), characterised by feathers , toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart , and

1080-402: The outermost half) can be seen in the evolution of maniraptoromorphs, and this process culminated in the appearance of the pygostyle , an ossification of fused tail vertebrae. In the late Cretaceous, about 100 million years ago, the ancestors of all modern birds evolved a more open pelvis, allowing them to lay larger eggs compared to body size. Around 95 million years ago, they evolved

1120-528: The previously clear distinction between non-birds and birds has become blurred. By the 2000s, discoveries in the Liaoning Province of northeast China, which demonstrated many small theropod feathered dinosaurs , contributed to this ambiguity. The consensus view in contemporary palaeontology is that the flying theropods, or avialans , are the closest relatives of the deinonychosaurs , which include dromaeosaurids and troodontids . Together, these form

1160-449: The same answers if done correctly. Given a particular wing and its velocity through the air, debates over which mathematical approach is the most convenient to use can be mistaken by those not familiar with the study of aerodynamics as differences of opinion about the basic principles of flight. Wings with an asymmetrical cross-section are the norm in subsonic flight . Wings with a symmetrical cross-section can also generate lift by using

1200-452: The same biological name "Aves", which is a problem. The authors proposed to reserve the term Aves only for the crown group consisting of the last common ancestor of all living birds and all of its descendants, which corresponds to meaning number 4 below. They assigned other names to the other groups.   Lizards & snakes   Turtles   Crocodiles   Birds Under the fourth definition Archaeopteryx , traditionally considered one of

1240-545: The second toe which may have been held clear of the ground in life, and long feathers or "hind wings" covering the hind limbs and feet, which may have been used in aerial maneuvering. Avialans diversified into a wide variety of forms during the Cretaceous period. Many groups retained primitive characteristics , such as clawed wings and teeth, though the latter were lost independently in a number of avialan groups, including modern birds (Aves). Increasingly stiff tails (especially

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1280-401: The top of the wing generates a smaller downward force on the top of the wing than the upward force generated by the higher air pressure on the bottom of the wing. This gives an upward force on the wing. This force is called the lift generated by the wing. The different velocities of the air passing by the wing, the air pressure differences, the change in direction of the airflow, and the lift on

1320-511: The upper surfaces of the inner panels, with turbulators on the underside to ensure a controlled boundary layer transition from laminar to turbulent flow without separation. The wings have 3° of dihedral . Though the Discus and the Carat share wings, they position them differently: the Discus is a mid-wing aircraft, the Carat a low-wing one. Like the Discus, the Carat has a high T-tail with separate tailplane and elevators . The tailplane, like

1360-527: The very pronounced increase in drag associated with airflow near the speed of sound. These airfoils, called supercritical airfoils , are flat on top and curved on the bottom. Aircraft wings may feature some of the following: Aircraft wings may have various devices, such as flaps or slats, that the pilot uses to modify the shape and surface area of the wing to change its operating characteristics in flight. Besides fixed-wing aircraft , applications for wing shapes include: In 1948, Francis Rogallo invented

1400-405: The wing are different ways of describing how lift is produced so it is possible to calculate lift from any one of the other three. For example, the lift can be calculated from the pressure differences, or from different velocities of the air above and below the wing, or from the total momentum change of the deflected air. Fluid dynamics offers other approaches to solving these problems—and all produce

1440-454: The wing. Lower-than-ambient air pressure is generated on the top surface of the wing, with a higher-than ambient-pressure on the bottom of the wing. (See: airfoil ) These air pressure differences can be either measured using a pressure-measuring device, or can be calculated from the airspeed] using physical principles —including Bernoulli's principle , which relates changes in air speed to changes in air pressure. The lower air pressure on

1480-477: The wings of aircraft is one of the principal applications of the science of aerodynamics , which is a branch of fluid mechanics . The properties of the airflow around any moving object can be found by solving the Navier-Stokes equations of fluid dynamics . Except for simple geometries, these equations are difficult to solve. Simpler explanations can be given For a wing to produce "lift", it must be oriented at

1520-424: The wings, is detachable for easy transport. The cockpit , enclosed in a large clear single piece canopy , is at the trailing edge of the wing, with the main spar under the pilot's knees. The Carat has a conventional electrically-operated inwardly retractable undercarriage . The main wheels have hydraulically operated disc brakes and there is a parking brake. The non-retractable tailwheel is steerable. The Carat

1560-461: Was developed by Francis Willughby and John Ray in their 1676 volume Ornithologiae . Carl Linnaeus modified that work in 1758 to devise the taxonomic classification system currently in use. Birds are categorised as the biological class Aves in Linnaean taxonomy . Phylogenetic taxonomy places Aves in the clade Theropoda as an infraclass or a subclass, more recently a subclass. Aves and

1600-674: Was made on 16 December 1997 and the first production model displayed at Aero '99 at Friedrichshafen in April 1999 as the Technoflug TFK-2 Carat. Certification was achieved in 2003, by which time marketing had been passed to AMS. Six production aircraft had been built by the end of 2003 and thirty one by September 2009. The majority of these were flying in the United States, the rest mostly in Western Europe . Data from Jane's All

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