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142-690: It was a 1,000-acre (400 ha) site begun in October 1935. The first wind tunnel was begun in November 1936. Most of the sixty buildings, scattered around the site, did not exceed treetop height, and all were well- camouflaged , to reduce the chance of them being detected by aerial reconnaissance and to avoid making them targets, as the wind tunnels of the Deutsche Versuchsanstalt für Luftfahrt ( DVL ) in Adlershof (near Berlin ) or

284-615: A B-17. Actually, it was still easier to kill a B-24, which was somewhat weaker in respect of fuselage strength and armament. I think we generally had the better armament and ammunition, whereas they had the better aircraft. The number of heavy bombers destroyed by the Fw ;190 is impossible to estimate. However, below is a list of the top scoring Sturmbock pilots: A total of 13,291 Fw 190 A-model aircraft were produced. A-6, A-7, and A-8 were modified for Sturmböcke bomber-destroyer operations. Tank started looking at ways to address

426-436: A background that is brighter than an animal's body or military vehicle; it is a form of active camouflage. It is notably used by some species of squid , such as the firefly squid and the midwater squid . The latter has light-producing organs ( photophores ) scattered all over its underside; these create a sparkling glow that prevents the animal from appearing as a dark shape when seen from below. Counterillumination camouflage

568-429: A clear evolutionary advantage in plants: they would tend to escape from being eaten by herbivores . Another possibility is that some plants have leaves differently coloured on upper and lower surfaces or on parts such as veins and stalks to make green-camouflaged insects conspicuous, and thus benefit the plants by favouring the removal of herbivores by carnivores. These hypotheses are testable. Some animals, such as

710-403: A combination of the two. Most forms of camouflage are ineffective when the camouflaged animal or object moves, because the motion is easily seen by the observing predator, prey or enemy. However, insects such as hoverflies and dragonflies use motion camouflage : the hoverflies to approach possible mates, and the dragonflies to approach rivals when defending territories. Motion camouflage

852-454: A few as static display models, with airworthy examples usually powered by Chinese-manufactured Shvetsov ASh-82 twin-row, 14-cylinder radial powerplants, which have a displacement of 41.2 litres, close to the BMW 801's 41.8 litres, with the same engine cylinder arrangement and number of cylinders. The nearly intact wreck of an Fw 190 A-5/U3 ( Werknummer 151 227) that had crashed in a marsh in

994-442: A fish can be seen by a factor of 6 compared to a fish with a nominal 2% reflectance. Species with this adaptation are widely dispersed in various orders of the phylogenetic tree of bony fishes ( Actinopterygii ), implying that natural selection has driven the convergent evolution of ultra-blackness camouflage independently many times. In mimesis (also called masquerade ), the camouflaged object looks like something else which

1136-762: A forest near Leningrad , Soviet Union, 1943 was located in 1989. After restoration in the US, the Fw 190 flew again (with the original BMW 801 powerplant) on 1 December 2010. Following the successful test flight, the aircraft was then trucked up to the Flying Heritage & Combat Armor Museum in Everett, Washington, where it was reassembled in April 2011 and returned to airworthy condition. At least five surviving Fw 190A radial-engined aircraft are known to have been assigned to

1278-399: A further refinement to this basic concept. He suggested placing most of the airflow components on the propeller, in the form of an oversized propeller spinner whose outside diameter was the same as the engine. The cowl around the engine proper was greatly simplified, essentially a basic cylinder. Air entered through a small hole at the centre of the spinner and was directed through ductwork in

1420-475: A high contrast pattern that could be disruptive coloration, the adults are very conspicuous when in the open. Some authors have argued that adult giraffes are cryptic, since when standing among trees and bushes they are hard to see at even a few metres' distance. However, adult giraffes move about to gain the best view of an approaching predator, relying on their size and ability to defend themselves, even from lions, rather than on camouflage. A different explanation

1562-486: A high-altitude interceptor. From the Fw 190's inception, there had been ongoing efforts to address this with a turbosupercharged BMW 801 in the B model, the much longer-nosed C model with efforts to also turbocharge its chosen Daimler-Benz DB 603 inverted V12 powerplant, and the similarly long-nosed D model with the Junkers Jumo 213 . Problems with the turbocharger installations on the -B and -C subtypes meant only

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1704-519: A mirror oriented vertically makes animals such as fish invisible from the side. Most fish in the upper ocean such as sardine and herring are camouflaged by silvering. The marine hatchetfish is extremely flattened laterally, leaving the body just millimetres thick, and the body is so silvery as to resemble aluminium foil . The mirrors consist of microscopic structures similar to those used to provide structural coloration : stacks of between 5 and 10 crystals of guanine spaced about 1 ⁄ 4 of

1846-494: A pair of Fw 190s on standby to supplement the Messerschmitt Bf 110 and Junkers Ju 88 . The considerable performance advantage of the Fw 190 over the other two types was more than offset by the difficulties of operating at night. Few, if any, aerial successes can be attributed to these operational tests. One of the first purpose built units to use Fw 190s in this role was Stab/Versuchskommando Herrmann ,

1988-404: A particularly black skin which reflected only 0.044% of 480 nm wavelength light. The ultra-blackness is achieved with a thin but continuous layer of particles in the dermis , melanosomes . These particles both absorb most of the light, and are sized and shaped so as to scatter rather than reflect most of the rest. Modelling suggests that this camouflage should reduce the distance at which such

2130-411: A period of about 8000 years the single agouti gene developed 9 mutations that each made expression of yellow fur stronger under natural selection, and largely eliminated melanin-coding black fur coloration. On the other hand, all black domesticated cats have deletions of the agouti gene that prevent its expression, meaning no yellow or red color is produced. The evolution, history and widespread scope of

2272-519: A potent "punch" from its stable gun platform, was considered ideal for anti-bomber operations. Focke-Wulf redesigned parts of the wing structure to accommodate larger armament. The Fw 190 A-6 was the first sub-variant to undergo this change. Its standard armament was increased from four MG 151 /20s to two of them with four more in two underwing cannon pods. The aircraft was designated A-6/R1 ( Rüstsatz ; or field conversion model). The first aircraft were delivered on 20 November 1943. Brief trials saw

2414-546: A potent bomber-killer. The A-7 evolved in November 1943. Two synchronized 13 mm (.51 inch) MG 131 machine guns replaced the twin cowl-mount synchronized 7.92 mm (.318 inch) MG 17 machine guns. The A-7/R variants could carry two 30 mm MK 108s as well as BR 21 rockets. This increased its potency as a Pulk-Zerstörer (Bomber Formation Destroyer). The A-8/R2 was the most numerous Sturmbock aircraft, some 900 were built by Fiesler at Kassel with 30 mm MK 108s installed in their outer wing panel mounts. While formidable bomber-killers,

2556-502: A predator blends in with the background, enabling it to approach prey). His experiments showed that swallow-tailed moth pupae were camouflaged to match the backgrounds on which they were reared as larvae . Poulton's "general protective resemblance" was at that time considered to be the main method of camouflage, as when Frank Evers Beddard wrote in 1892 that "tree-frequenting animals are often green in colour. Among vertebrates numerous species of parrots , iguanas , tree-frogs , and

2698-409: A reason, such as to lure prey. For example, the nematocysts (stinging cells) of the transparent siphonophore Agalma okenii resemble small copepods . Examples of transparent marine animals include a wide variety of larvae , including radiata (coelenterates), siphonophores, salps (floating tunicates ), gastropod molluscs , polychaete worms, many shrimplike crustaceans , and fish; whereas

2840-693: A reproductive advantage, enabling them to leave more offspring, on average, than other members of the same species . In his Origin of Species , Darwin wrote: When we see leaf-eating insects green, and bark-feeders mottled-grey; the alpine ptarmigan white in winter, the red-grouse the colour of heather , and the black-grouse that of peaty earth, we must believe that these tints are of service to these birds and insects in preserving them from danger. Grouse, if not destroyed at some period of their lives, would increase in countless numbers; they are known to suffer largely from birds of prey ; and hawks are guided by eyesight to their prey, so much so, that on parts of

2982-505: A small elastic sac, which can be stretched or allowed to relax under the control of the brain to vary its opacity. By controlling chromatophores of different colours, cephalopods can rapidly change their skin patterns and colours. On a longer timescale, animals like the Arctic hare , Arctic fox , stoat , and rock ptarmigan have snow camouflage , changing their coat colour (by moulting and growing new fur or feathers) from brown or grey in

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3124-416: A species of nudibranch that feeds on stony coral , utilizes specific cryptic patterning in reef ecosystems. The nudibranch syphons pigments from the consumed coral into the epidermis, adopting the same shade as the consumed coral. This allows the nudibranch to change colour (mostly between black and orange) depending on the coral system that it inhabits. However, P. melanocrachia can only feed and lay eggs on

3266-597: A unit specifically set up in April 1943 by Major Hajo Herrmann . Herrmann's unit used standard A-4s and A-5s borrowed from day fighter units to intercept bombers over or near the targeted city, using searchlights and other visual aids to help them find their quarry. The first use of "Window" by the RAF during the Battle of Hamburg in July 1943, rendered the standard nightfighter Himmelbett procedures useless and brought urgency to

3408-409: A wavelength apart to interfere constructively and achieve nearly 100 per cent reflection. In the deep waters that the hatchetfish lives in, only blue light with a wavelength of 500 nanometres percolates down and needs to be reflected, so mirrors 125 nanometres apart provide good camouflage. In fish such as the herring which live in shallower water, the mirrors must reflect a mixture of wavelengths, and

3550-571: Is a German single-seat, single-engine fighter aircraft designed by Kurt Tank at Focke-Wulf in the late 1930s and widely used during World War II . Along with its well-known counterpart, the Messerschmitt Bf 109 , the Fw 190 became the backbone of the Jagdwaffe (Fighter Force) of the Luftwaffe . The twin-row BMW 801 radial engine that powered most operational versions enabled

3692-452: Is acellular and highly transparent. This conveniently makes them buoyant , but it also makes them large for their muscle mass, so they cannot swim fast, making this form of camouflage a costly trade-off with mobility. Gelatinous planktonic animals are between 50 and 90 percent transparent. A transparency of 50 percent is enough to make an animal invisible to a predator such as cod at a depth of 650 metres (2,130 ft); better transparency

3834-475: Is achieved by moving so as to stay on a straight line between the target and a fixed point in the landscape; the pursuer thus appears not to move, but only to loom larger in the target's field of vision. Some insects sway while moving to appear to be blown back and forth by the breeze. The same method can be used for military purposes, for example by missiles to minimise their risk of detection by an enemy. However, missile engineers, and animals such as bats, use

3976-433: Is an important component of camouflage in all environments. For instance, tree-dwelling parakeets are mainly green; woodcocks of the forest floor are brown and speckled; reedbed bitterns are streaked brown and buff; in each case the animal's coloration matches the hues of its habitat. Similarly, desert animals are almost all desert coloured in tones of sand, buff, ochre, and brownish grey, whether they are mammals like

4118-436: Is argued that these juvenile giraffes must be very well camouflaged; this is supported by coat markings being strongly inherited . The possibility of camouflage in plants was little studied until the late 20th century. Leaf variegation with white spots may serve as camouflage in forest understory plants, where there is a dappled background; leaf mottling is correlated with closed habitats. Disruptive camouflage would have

4260-418: Is common in military usage, both for uniforms and for military vehicles. Disruptive patterning, however, does not always achieve crypsis on its own, as an animal or a military target may be given away by factors like shape, shine, and shadow. The presence of bold skin markings does not in itself prove that an animal relies on camouflage, as that depends on its behaviour. For example, although giraffes have

4402-435: Is fossil evidence of camouflaged insects going back over 100 million years, for example lacewings larvae that stick debris all over their bodies much as their modern descendants do, hiding them from their prey. Dinosaurs appear to have been camouflaged, as a 120 million year old fossil of a Psittacosaurus has been preserved with countershading . Camouflage does not have a single genetic origin. However, studying

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4544-403: Is implied by young giraffes being far more vulnerable to predation than adults. More than half of all giraffe calves die within a year, and giraffe mothers hide their newly born calves, which spend much of the time lying down in cover while their mothers are away feeding. The mothers return once a day to feed their calves with milk. Since the presence of a mother nearby does not affect survival, it

4686-525: Is less often used for military camouflage, despite Second World War experiments that showed its effectiveness. English zoologist Hugh Cott encouraged the use of methods including countershading, but despite his authority on the subject, failed to persuade the British authorities. Soldiers often wrongly viewed camouflage netting as a kind of invisibility cloak, and they had to be taught to look at camouflage practically, from an enemy observer's viewpoint. At

4828-434: Is mediated by a type of chromatophore known as melanophores that contain dark pigment. A melanophore is star-shaped; it contains many small pigmented organelles which can be dispersed throughout the cell, or aggregated near its centre. When the pigmented organelles are dispersed, the cell makes a patch of the animal's skin appear dark; when they are aggregated, most of the cell, and the animal's skin, appears light. In frogs,

4970-540: Is not every reason to believe it the very best conceivable device for the concealment of its wearer", and using paintings such as Peacock in the Woods (1907) to reinforce his argument. Thayer was roundly mocked for these views by critics including Teddy Roosevelt . The English zoologist Hugh Cott 's 1940 book Adaptive Coloration in Animals corrected Thayer's errors, sometimes sharply: "Thus we find Thayer straining

5112-438: Is of no special interest to the observer. Mimesis is common in prey animals, for example when a peppered moth caterpillar mimics a twig, or a grasshopper mimics a dry leaf. It is also found in nest structures; some eusocial wasps, such as Leipomeles dorsata , build a nest envelope in patterns that mimic the leaves surrounding the nest. Focke-Wulf Fw 190 The Focke-Wulf Fw 190 , nicknamed Würger ( Shrike )

5254-739: Is possible that some plants use camouflage to evade being eaten by herbivores . Military camouflage was spurred by the increasing range and accuracy of firearms in the 19th century. In particular the replacement of the inaccurate musket with the rifle made personal concealment in battle a survival skill. In the 20th century, military camouflage developed rapidly, especially during the First World War . On land, artists such as André Mare designed camouflage schemes and observation posts disguised as trees. At sea , merchant ships and troop carriers were painted in dazzle patterns that were highly visible, but designed to confuse enemy submarines as to

5396-463: Is required for invisibility in shallower water, where the light is brighter and predators can see better. For example, a cod can see prey that are 98 percent transparent in optimal lighting in shallow water. Therefore, sufficient transparency for camouflage is more easily achieved in deeper waters. Some tissues such as muscles can be made transparent, provided either they are very thin or organised as regular layers or fibrils that are small compared to

5538-483: Is the likely function of the bioluminescence of many marine organisms, though light is also produced to attract or to detect prey and for signalling. Counterillumination has rarely been used for military purposes. " Diffused lighting camouflage " was trialled by Canada's National Research Council during the Second World War. It involved projecting light on to the sides of ships to match the faint glow of

5680-428: Is their mutual resemblance." He also explained the coloration of sea fish such as the mackerel : "Among pelagic fish it is common to find the upper surface dark-coloured and the lower surface white, so that the animal is inconspicuous when seen either from above or below." The artist Abbott Handerson Thayer formulated what is sometimes called Thayer's Law, the principle of countershading . However, he overstated

5822-474: Is thought to have originated through transposition from symbiotic Aliivibrio fischeri bacteria, which provide bioluminescence to its hosts. While not all cephalopods use active camouflage , ancient cephalopods may have inherited the gene horizontally from symbiotic A. fischeri , with divergence occurred through subsequent gene duplication (such as in the case of Sepia officinalis ) or gene loss (as with cephalopods with no active camouflage capabilities). This

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5964-640: Is unique as an instance of camouflage arising as an instance of horizontal gene transfer from an endosymbiont . However, other methods of horizontal gene transfer are common in the evolution of camouflage strategies in other lineages. Peppered moths and walking stick insects both have camouflage-related genes that stem from transposition events. The Agouti genes are orthologous genes involved in camouflage across many lineages. They produce yellow and red coloration ( phaeomelanin ), and work in competition with other genes that produce black (melanin) and brown (eumelanin) colours. In eastern deer mice , over

6106-601: The Aerodynamische Versuchsanstalt ( AVA , part of today's DLR agency ) at the University of Göttingen were. The buildings were in five groups. The Institute of Aerodynamics had five wind tunnels , while the Institute of Gas Dynamics had its own high-speed tunnel; both were at the southern end of the campus. The static testing station of the Institute of Strength Properties was to the west;

6248-608: The BMW firm in developing the factory-produced forward cowling — which had the engine's oil cooler integrated into it from the beginning — for their BMW 801 fourteen-cylinder radial engine used in many German Luftwaffe military aircraft, most importantly the Focke-Wulf Fw 190 A; trials indicated it was possible to reduce drag enough to save 150–200 hp (110–150 kW; 150–200 PS), as well as to maximize pressure build-up to assist cooling. It also helped in development of

6390-412: The battledress of a modern soldier , and the leaf-mimic katydid 's wings. A third approach, motion dazzle, confuses the observer with a conspicuous pattern, making the object visible but momentarily harder to locate. The majority of camouflage methods aim for crypsis, often through a general resemblance to the background, high contrast disruptive coloration , eliminating shadow, and countershading . In

6532-548: The gerbil or fennec fox , birds such as the desert lark or sandgrouse , or reptiles like the skink or horned viper . Military uniforms, too, generally resemble their backgrounds; for example khaki uniforms are a muddy or dusty colour, originally chosen for service in South Asia. Many moths show industrial melanism , including the peppered moth which has coloration that blends in with tree bark. The coloration of these insects evolved between 1860 and 1940 to match

6674-409: The green tree-snake are examples". Beddard did however briefly mention other methods, including the "alluring coloration" of the flower mantis and the possibility of a different mechanism in the orange tip butterfly . He wrote that "the scattered green spots upon the under surface of the wings might have been intended for a rough sketch of the small flowerets of the plant [an umbellifer ], so close

6816-401: The horned lizards of North America, have evolved elaborate measures to eliminate shadow . Their bodies are flattened, with the sides thinning to an edge; the animals habitually press their bodies to the ground; and their sides are fringed with white scales which effectively hide and disrupt any remaining areas of shadow there may be under the edge of the body. The theory that the body shape of

6958-511: The 109 and Messerschmitt Bf 110 for engine supplies. After the war, Tank denied a rumour that he had to "fight a battle" with the Ministry to convince them of the radial engine's merits. At the time, the use of radial engines in land-based fighters was relatively rare in Europe, as it was believed that their large frontal area would cause too much drag on something as small as a fighter. Tank

7100-533: The Allied air forces never bombed it. Postwar, the Fedden Mission of a Ministry of Aircraft Production team led by Roy Fedden visited the site. Camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard 's spotted coat,

7242-663: The Ar 80. The He 112 and Bf 109 were generally similar in design but the 109's lightweight construction gave it a performance edge the 112 was never able to match. On March 12, 1936, the 109 was declared the winner. Even before the Bf ;109 had entered squadron service, in autumn 1937 the RLM sent out a new tender asking various designers for a new fighter to fight alongside the Bf 109, as Walter Günther had done with Heinkel's follow-on to

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7384-553: The BMW 801 14-cylinder radial over the more troublesome BMW 139 also brought with it a BMW-designed cowling "system" which integrated the radiator used to cool the motor oil. An annular, ring-shaped oil cooler core was built into the BMW-provided forward cowl, just behind the fan. The outer portion of the oil cooler's core was in contact with the main cowling's sheet metal. Comprising the BMW-designed forward cowl, in front of

7526-403: The BMW 801 engine to increase performance at high altitude. For protection, 30 millimetres (1.2 in) of armoured glass was added to the canopy. The A-6/R6 was fitted with twin heavy calibre Werfer-Granate 21 (BR 21) unguided, air-to-air rockets, fired from single underwing tubular launchers (one per wing panel). The increased modifications, in particular heavy firepower, made the Fw 190

7668-401: The Bf 109, the Fw 190 featured a fairly small wing planform with relatively high wing loading . This presents a trade-off in performance. An aircraft with a smaller wing suffers less drag under most flight conditions and therefore flies faster and may have better range. However, it also means the aircraft has a higher stalling speed making it less maneuverable, and also reduces performance in

7810-542: The Bf 109 and Fw 190 were not adequate for bomber-destroyer operations. The B-17's eventual deployment in combat box formations provided formidable massed firepower from a hundred or more Browning AN/M2 .50 caliber (12.7 mm) machine guns. In addition, the Luftwaffe ' s original solution of Zerstörer twin-engine Messerschmitt Bf 110G bomber destroyers , while effective against unescorted Allied bomber formations, lacked maneuverability and were eviscerated by

7952-600: The British army having adopted "coats of motley hue and stripes of paint" for snipers. Cott takes the example of the larva of the blotched emerald moth, which fixes a screen of fragments of leaves to its specially hooked bristles, to argue that military camouflage uses the same method, pointing out that the "device is ... essentially the same as one widely practised during the Great War for the concealment, not of caterpillars, but of caterpillar-tractors, [gun] battery positions, observation posts and so forth." Movement catches

8094-663: The Continent persons are warned not to keep white pigeons, as being the most liable to destruction. Hence I can see no reason to doubt that natural selection might be most effective in giving the proper colour to each kind of grouse, and in keeping that colour, when once acquired, true and constant. The English zoologist Edward Bagnall Poulton studied animal coloration , especially camouflage. In his 1890 book The Colours of Animals , he classified different types such as "special protective resemblance" (where an animal looks like another object), or "general aggressive resemblance" (where

8236-632: The D model entered service in September 1944. These high-altitude developments eventually led to the Focke-Wulf Ta 152 , which was capable of extreme speeds at medium to high altitudes (755 km/h [408 kn; 469 mph] at 13,500 m [44,300 ft]). While these "long nose" 190 variants and the Ta 152 derivative especially gave the Germans parity with Allied opponents, they arrived too late to affect the outcome of

8378-419: The Fw 190 suffered fewer ground accidents than the Bf 109. (The Bf 109's narrow-track, outwards-retracting landing gear hinged on its wing root structure to help lower weight, but this led to inherent weakness and many failures and ground loops. ) The Fw 190's retractable tail gear used a cable, anchored to the "elbow" at the midpoint of the starboard maingear's transverse retraction arms, which ran aftwards within

8520-658: The Fw 190 to lift larger loads than the Bf 109, allowing its use as a day fighter , fighter-bomber , ground-attack aircraft and to a lesser degree, night fighter . The Fw 190A started flying operationally over France in August 1941 and quickly proved superior in all but turn radius to the Spitfire Mk. V , the main front-line fighter of the Royal Air Force (RAF), particularly at low and medium altitudes. The 190 maintained its superiority over Allied fighters until

8662-403: The Fw 190 used a canopy with a frame that ran around the perimeter, with only a short, centerline seam along the top, running rearward from the radio antenna fitting where the three-panel windscreen and the forward edge of the canopy met, just in front of the pilot. From mid-1943, Fw 190s were also used as night fighters against the growing RAF Bomber Command offensive. In mid-1943, one of

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8804-509: The Fw 190, in this version, was the best aircraft used in the formation against the Viermots . Richard Franz commented: When we made our attack, we approached from slightly above, then dived, opening fire with 13mm and 20mm guns to knock out the rear gunner and then, at about 150 metres, we tried to engage with the MK 108 30mm cannon, which was a formidable weapon. It could cut the wing off

8946-635: The Institute of Engine Research, the east. Weapons research was done by the Institute of Kinematics in a 400 m (1,300 ft)-long tunnel in the northwest corner. These were accompanied by administration buildings, a canteen , a telephone exchange , guard houses, generators, and other facilities. To help reduce the risk of detection, there were no railway lines in, nor overhead power lines, nor any chimneys; and uniquely for an aviation research facility of its time in Germany, no runways, taxiways or hardstands for active aviation operations; just about all of

9088-651: The Luftwaffe's JG 5 wing in Herdla, Norway. More German fighter aircraft on display in museums in the 21st century have originated from this unit than from any other Axis Powers' military aviation unit of World War II. The Turkish Air Force retired all of its Fw 190A-3 fleet at the end of 1947 mostly because of a lack of spare parts. It is rumored that American-Turkish bilateral agreements required retiring and scrapping of all German-origin aircraft, although that requirement did not exist for any other country. According to

9230-513: The USAAF's fighter escorts in late 1943 and early 1944. Two of the former Wilde Sau single-engined night fighter wings were reconstituted for their use, such as Jagdgeschwader 300 (JG 300—300th Fighter Wing) and JG 301 . These units consisted of Sturmböcke . However, JG 3 also had a special gruppe (group) of Sturmböcke. The Fw 190, designed as a rugged interceptor capable of withstanding considerable combat damage and delivering

9372-690: The Western Front in August 1941, where it proved superior to the Mk V Spitfire. The Spitfire's main advantage over the Fw 190, and the Bf 109 as well, was its superior turn radius. Beyond that, the Fw 190 outperformed the Spitfire Mk. V in most areas, such as roll rate, speed, acceleration, and dive performance. The addition of the Fw 190 to the Jagdwaffe allowed the Germans to fight off RAF attacks and achieve local air superiority over German skies until

9514-409: The adults of most of these are opaque and pigmented, resembling the seabed or shores where they live. Adult comb jellies and jellyfish obey the rule, often being mainly transparent. Cott suggests this follows the more general rule that animals resemble their background: in a transparent medium like seawater, that means being transparent. The small Amazon River fish Microphilypnus amazonicus and

9656-483: The agouti gene shows that different organisms often rely on orthologous or even identical genes to develop a variety of camouflage strategies. While camouflage can increase an organism's fitness, it has genetic and energetic costs. There is a trade-off between detectability and mobility. Species camouflaged to fit a specific microhabitat are less likely to be detected when in that microhabitat, but must spend energy to reach, and sometimes to remain in, such areas. Outside

9798-481: The air-cooled, 14-cylinder BMW 139 radial engine that the Ministry of Aviation's interest was aroused. As this design used a radial engine, it would not compete with the inline-powered Bf 109 for engines, when there were already too few Daimler-Benz DB 601s to go around. This was not the case for competing designs like the Heinkel He 100 or twin-engined Focke-Wulf Fw 187 , where production would compete with

9940-406: The aircraft's trim at varying speeds, thus reducing the pilot's workload. They were so successful in this regard that they found in-flight-adjustable aileron and rudder trim tabs were not necessary. Small, fixed tabs were fitted to control surfaces and adjusted for proper balance during initial test flights. Only the elevator trim needed to be adjusted in flight (a feature common to all aircraft). This

10082-405: The altitude performance problem early in the program. In 1941, he proposed a number of versions featuring new powerplants, and he suggested using turbochargers in place of superchargers. Three such installations were outlined The Fw 190 participated on every major combat front where the Luftwaffe operated after 1941, and did so with success in a variety of roles. The Fw 190 first tasted combat on

10224-636: The armour and substantial up-gunning with heavier calibre firepower meant the Fw 190 was now cumbersome to maneuver. Vulnerable to Allied fighters, they had to be escorted by Bf 109s. When the Sturmgruppe was able to work as intended, the effects were devastating. With their engines and cockpits heavily armored, the Fw 190 As attacked from astern and gun camera films show that these attacks were often pressed to within 100 yds (90 m). Willy Unger of 11.( Sturm )/JG 3 (11 Staffel (Squadron) of Sturmgruppe (Storm group) JG 3) made

10366-521: The best fighter planes of World War II. Between 1934 and 1935 the German Ministry of Aviation (RLM) ran a contest to produce a modern fighter for the rearming Luftwaffe. Kurt Tank entered the parasol-winged Fw 159 into the contest, against the Arado Ar 80 , Heinkel He 112 and Messerschmitt Bf 109. The Fw 159 was hopelessly outclassed and was soon eliminated from the competition along with

10508-438: The body outline, making it harder to precisely identify and locate. However, disruptive patterns result in higher predation. Disruptive patterns that specifically involve visible symmetry (such as in some butterflies) reduce survivability and increase predation. Some researchers argue that because wing-shape and color pattern are genetically linked, it is genetically costly to develop asymmetric wing colorations that would enhance

10650-456: The body. On these, the nymph spreads an inner layer of fine particles and an outer layer of coarser particles. The camouflage may conceal the bug from both predators and prey. Similar principles can be applied for military purposes, for instance when a sniper wears a ghillie suit designed to be further camouflaged by decoration with materials such as tufts of grass from the sniper's immediate environment. Such suits were used as early as 1916,

10792-442: The branches of host-coral, Platygyra carnosa , which limits the geographical range and efficacy in nudibranch nutritional crypsis. Furthermore, the nudibranch colour change is not immediate, and switching between coral hosts when in search for new food or shelter can be costly. The costs associated with distractive or disruptive crypsis are more complex than the costs associated with background matching. Disruptive patterns distort

10934-457: The camouflage consists of two surfaces, each with the simple function of providing concealment against a specific background, such as a bright water surface or the sky. The body of a shark or the fuselage of an aircraft is not gradated from light to dark to appear flat when seen from the side. The camouflage methods used are the matching of background colour and pattern, and disruption of outlines. Counter-illumination means producing light to match

11076-468: The case in the 1909 book Concealing-Coloration in the Animal Kingdom , arguing that "All patterns and colors whatsoever of all animals that ever preyed or are preyed on are under certain normal circumstances obliterative" (that is, cryptic camouflage), and that "Not one ' mimicry ' mark, not one ' warning color '... nor any ' sexually selected ' color, exists anywhere in the world where there

11218-454: The cavalry and in the infantry. I had seen the harsh conditions under which military equipment had to work in wartime. I felt sure that a quite different breed of fighter would also have a place in any future conflict: one that could operate from ill-prepared front-line airfields; one that could be flown and maintained by men who had received only short training; and one that could absorb a reasonable amount of battle damage and still get back. This

11360-403: The change is controlled relatively slowly, mainly by hormones . In fish, the change is controlled by the brain, which sends signals directly to the chromatophores, as well as producing hormones. The skins of cephalopods such as the octopus contain complex units, each consisting of a chromatophore with surrounding muscle and nerve cells. The cephalopod chromatophore has all its pigment grains in

11502-411: The changing colour of the tree trunks on which they rest, from pale and mottled to almost black in polluted areas. This is taken by zoologists as evidence that camouflage is influenced by natural selection , as well as demonstrating that it changes where necessary to resemble the local background. Disruptive patterns use strongly contrasting, non-repeating markings such as spots or stripes to break up

11644-540: The colour-changing abilities, both for camouflage and for signalling , of cephalopods including the octopus, in his Historia animalium : The octopus  ... seeks its prey by so changing its colour as to render it like the colour of the stones adjacent to it; it does so also when alarmed . Camouflage has been a topic of interest and research in zoology for well over a century. According to Charles Darwin 's 1859 theory of natural selection , features such as camouflage evolved by providing individual animals with

11786-411: The combination of behaviours and other methods of crypsis involved, young giraffes seek cover, lie down, and keep still, often for hours until their mothers return; their skin pattern blends with the pattern of the vegetation, while the chosen cover and lying position together hide the animals' shadows. The flat-tail horned lizard similarly relies on a combination of methods: it is adapted to lie flat in

11928-439: The complex, failure-prone fuselage-mounted main gear legs of the earlier Fw 159, one of the main features of the Fw 190 was its wide-tracked, inwards-retracting landing gear. They were designed to withstand a sink rate of 4.5 metres per second (15 ft/s; 890 ft/min), double the strength factor usually required. Hydraulic wheel brakes were used. The wide-track undercarriage produced better ground handling characteristics, and

12070-504: The countershaded animal nearly invisible against a suitable background. Thayer observed that "Animals are painted by Nature, darkest on those parts which tend to be most lighted by the sky's light, and vice versa ". Accordingly, the principle of countershading is sometimes called Thayer's Law . Countershading is widely used by terrestrial animals , such as gazelles and grasshoppers; marine animals, such as sharks and dolphins ; and birds, such as snipe and dunlin . Countershading

12212-441: The development of Herrmann's Wilde Sau ("Wild Boar") technique, pending the development of new nightfighting strategies. Instead of restricting the Fw 190s to ground control interception protocols, the Fw 190s were given a free hand to over-fly bombed areas to see if they could locate bombers using the ground fires below. These tactics became an integral part of the nightfighter operations until May 1944. St/V Herrmann

12354-681: The earliest participants in the single-engine, ground controlled, night-fighting experiments was the Nachtjagdkommando Fw ;190 (Night Fighter Command Fw 190), operated by IV. Gruppe (4 Group), Jagdgeschwader 3 , (Fighter Wing 3, or JG 3). The main Nachtgeschwader (Night Fighter Wings) were keen to adopt a new fighter type as their twin-engine fighters were too slow for combat against increasing numbers of de Havilland Mosquito night fighters and bombers. Nachtjagdgeschwader 1 (NJG 1) and NJG 3 kept

12496-502: The efficacy of disruptive cryptic patterning. Symmetry does not carry a high survival cost for butterflies and moths that their predators views from above on a homogeneous background, such as the bark of a tree. On the other hand, natural selection drives species with variable backgrounds and habitats to move symmetrical patterns away from the centre of the wing and body, disrupting their predators' symmetry recognition. Camouflage can be achieved by different methods, described below. Most of

12638-405: The engine. The second was to warm the air before it flowed to the radiator to aid in warming the oil during starting. Finally, by placing the radiator behind the fan, cooling was provided even while the aircraft was parked. The disadvantage to this design was that the radiator was in an extremely vulnerable location, and the metal ring was increasingly armoured as the war progressed. In contrast to

12780-419: The eye of prey animals on the lookout for predators, and of predators hunting for prey. Most methods of crypsis therefore also require suitable cryptic behaviour, such as lying down and keeping still to avoid being detected, or in the case of stalking predators such as the tiger , moving with extreme stealth, both slowly and quietly, watching its prey for any sign they are aware of its presence. As an example of

12922-501: The facility's infrastructure needs were supplied underground from Braunschweig, including steam heat . In addition, there were four hundred houses in Völkenrode for the 1,500 or so workers and scientists. Each of the wind tunnels at LFA was given an "A" number. A1 had a circular nozzle 2.5 m (8 ft 2 in) in diameter, producing a maximum speed of 123 mph (198 km/h; 107 kn); it entered service in 1937,

13064-400: The features of their bodies, and to match their backgrounds. For example, a caddisfly larva builds a decorated case and lives almost entirely inside it; a decorator crab covers its back with seaweed, sponges, and stones. The nymph of the predatory masked bug uses its hind legs and a ' tarsal fan' to decorate its body with sand or dust. There are two layers of bristles ( trichomes ) over

13206-738: The fish accordingly has crystal stacks with a range of different spacings. A further complication for fish with bodies that are rounded in cross-section is that the mirrors would be ineffective if laid flat on the skin, as they would fail to reflect horizontally. The overall mirror effect is achieved with many small reflectors, all oriented vertically. Silvering is found in other marine animals as well as fish. The cephalopods , including squid, octopus and cuttlefish, have multilayer mirrors made of protein rather than guanine. Some deep sea fishes have very black skin, reflecting under 0.5% of ambient light. This can prevent detection by predators or prey fish which use bioluminescence for illumination. Oneirodes had

13348-440: The following comments: Advantages; wide undercarriage, large twin-row radial engine which protected the pilot from the front, electric starter motor and electric trim system. Disadvantages; there was a danger of turning over when braking hard on soft or sandy ground. In combat against enemy fighters, more awkward because of the heavy armour plating. Strong at low altitude, inferior to the Bf 109 at higher altitude. In my opinion

13490-485: The front face of the engine open to the air, causing considerable drag . During the late 1920s, NACA led the development of a dramatic improvement by placing an airfoil -shaped ring around the outside of the cylinder heads (the NACA cowling ). The shaping accelerated the air as it entered the front of the cowl, increasing the total airflow, and allowing the opening in front of the engine to be made smaller. Tank introduced

13632-410: The front of the engine forward across the oil cooler core to provide cooling for the 801's motor oil. The rate of cooling airflow over the core could be controlled by moving the metal ring to open or close the gap. The reasons for this complex system were threefold. One was to reduce any extra aerodynamic drag of the oil radiator, in this case largely eliminating it by placing it within the same cowling as

13774-407: The fuselage to the vertical fin to operate the tailwheel retraction function. The tailwheel's retraction mechanical design possessed a set of pulleys to guide the aforementioned cable to the top of the tailwheel's oleo strut , pulling it upwards along a diagonal track within the fin, into the lower fuselage; this mechanism was accessible through a prominently visible triangular-shaped hinged panel, on

13916-482: The genetic components and various ecological pressures that drive crypsis. Camouflage is a soft-tissue feature that is rarely preserved in the fossil record, but rare fossilised skin samples from the Cretaceous period show that some marine reptiles were countershaded. The skins, pigmented with dark-coloured eumelanin , reveal that both leatherback turtles and mosasaurs had dark backs and light bellies. There

14058-436: The genetic components of camouflage in specific organisms illuminates the various ways that crypsis can evolve among lineages. Many cephalopods have the ability to actively camouflage themselves, controlling crypsis through neural activity. For example, the genome of the common cuttlefish includes 16 copies of the reflectin gene, which grants the organism remarkable control over coloration and iridescence. The reflectin gene

14200-399: The horned lizards which live in open desert is adapted to minimise shadow is supported by the one species which lacks fringe scales, the roundtail horned lizard , which lives in rocky areas and resembles a rock. When this species is threatened, it makes itself look as much like a rock as possible by curving its back, emphasizing its three-dimensional shape. Some species of butterflies, such as

14342-502: The introduction of the improved Spitfire Mk. IX . In November/December 1942, the Fw 190 made its air combat debut on the Eastern Front , finding much success in fighter wings and specialised ground attack units ( Schlachtgeschwader – Battle Wings or Strike Wings) from October 1943. The Fw 190A series' performance decreased at high altitudes (usually 6,000 m [20,000 ft] and above), which reduced its effectiveness as

14484-476: The left side in the fin's side sheetmetal covering. On some versions of the Fw 190 an extended tailwheel oleo strut could be fitted for larger-sized loads (such as bombs or even a torpedo) beneath the fuselage. Most aircraft of the era used cables and pulleys to operate their controls. The cables tended to stretch, resulting in the sensations of "give" and "play" that made the controls less crisp and responsive, and required constant maintenance to correct. For

14626-423: The local environment. As there is a lack of evidence for camouflage in the fossil record, studying the evolution of camouflage strategies is very difficult. Furthermore, camouflage traits must be both adaptable (provide a fitness gain in a given environment) and heritable (in other words, the trait must undergo positive selection ). Thus, studying the evolution of camouflage strategies requires an understanding of

14768-534: The method mainly for its efficiency rather than camouflage. Animals such as chameleon , frog, flatfish such as the peacock flounder , squid, octopus and even the isopod idotea balthica actively change their skin patterns and colours using special chromatophore cells to resemble their current background, or, as in most chameleons, for signalling . However, Smith's dwarf chameleon does use active colour change for camouflage. Each chromatophore contains pigment of only one colour. In fish and frogs, colour change

14910-428: The methods help to hide against a background; but mimesis and motion dazzle protect without hiding. Methods may be applied on their own or in combination. Many mechanisms are visual, but some research has explored the use of techniques against olfactory (scent) and acoustic (sound) detection. Methods may also apply to military equipment. Some animals' colours and patterns match a particular natural background. This

15052-466: The microhabitat, the organism has a higher chance of detection. Generalized camouflage allows species to avoid predation over a wide range of habitat backgrounds, but is less effective. The development of generalized or specialized camouflage strategies is highly dependent on the biotic and abiotic composition of the surrounding environment. There are many examples of the tradeoffs between specific and general cryptic patterning. Phestilla melanocrachia ,

15194-476: The new design, the team replaced the cables with rigid pushrods and bearings to eliminate this problem. Another innovation was making the controls as light as possible. The maximum resistance of the ailerons was limited to 3.5 kg (8 lb), as the average man's wrist could not exert a greater force. The empennage (tail assembly) featured relatively small and well-balanced horizontal and vertical surfaces. The design team also attempted to minimize changes in

15336-538: The night sky, requiring awkward external platforms to support the lamps. The Canadian concept was refined in the American Yehudi lights project, and trialled in aircraft including B-24 Liberators and naval Avengers . The planes were fitted with forward-pointing lamps automatically adjusted to match the brightness of the night sky. This enabled them to approach much closer to a target – within 3,000 yards (2,700 m) – before being seen. Counterillumination

15478-409: The oil cooler was a ring of metal with a C-shaped cross-section, with the outer lip lying just outside the rim of the cowl, and the inner side on the inside of the oil cooler core. Together, the metal ring and cowling formed an S-shaped duct with the oil cooler's core contained between them. Airflow past the gap between the cowl and outer lip of the metal ring produced a vacuum effect that pulled air from

15620-514: The open desert, relying on stillness, its cryptic coloration, and concealment of its shadow to avoid being noticed by predators. In the ocean, the leafy sea dragon sways mimetically, like the seaweeds amongst which it rests, as if rippled by wind or water currents. Swaying is seen also in some insects, like Macleay's spectre stick insect, Extatosoma tiaratum . The behaviour may be motion crypsis, preventing detection, or motion masquerade, promoting misclassification (as something other than prey), or

15762-442: The open ocean, where there is no background, the principal methods of camouflage are transparencying, silveringing, and countershading, while the ability to produce light is among other things used for counter-illumination on the undersides of cephalopods such as squid . Some animals, such as chameleons and octopuses , are capable of actively changing their skin pattern and colors , whether for camouflage or for signalling. It

15904-408: The outlines of an animal or military vehicle, or to conceal telltale features, especially by masking the eyes , as in the common frog . Disruptive patterns may use more than one method to defeat visual systems such as edge detection . Predators like the leopard use disruptive camouflage to help them approach prey, while potential prey use it to avoid detection by predators. Disruptive patterning

16046-558: The pioneering Argus As 014 pulsejet used in the V-1 . In collaboration with Göttingen and DVL (Berlin- Adlershof ), it also contributed to the development of the swept wing (what Germans called Pfeilflüge , or "arrow wing"). Among the engine projects worked on at LFA was a toroidal (swing-piston) design by Otto Lutz of Büssing , a concept akin to the Wankel ; work was also done by Junkers and Bosch . LFA remained so secret,

16188-677: The radial-engined Fw 190s was AGO Flugzeugwerke , which from 1941 through to the end of the war produced enough Fw 190s to earn it major attention from the USAAF , with the AGO plant in Oschersleben being attacked at least five times during the war from 1943 onwards. Some 28 original Fw 190s are in museums or in the hands of private collectors around the world. In 1997 a German company, Flug Werk GmbH, began manufacturing new Fw 190 models as reproductions. By 2012, 20 had been produced, most flyable,

16330-447: The research teams to rely on a Rheinmetall-Börsig F25 free-flight research rocket with models mounted in the nose. The A3 tunnel, largest at the LFA site, had an 8 m (26 ft 3 in) test section with a maximum speed of 95 m/s (210 mph; 185 kn) and a working length of 11 m (36 ft 1 in), enough to accommodate a Messerschmitt Bf 109 's fuselage. It

16472-474: The same time in Australia , zoologist William John Dakin advised soldiers to copy animals' methods, using their instincts for wartime camouflage. The term countershading has a second meaning unrelated to "Thayer's Law". It is that the upper and undersides of animals such as sharks, and of some military aircraft, are different colours to match the different backgrounds when seen from above or from below. Here

16614-467: The shrimps it associates with, Pseudopalaemon gouldingi , are so transparent as to be "almost invisible"; further, these species appear to select whether to be transparent or more conventionally mottled (disruptively patterned) according to the local background in the environment. Where transparency cannot be achieved, it can be imitated effectively by silvering to make an animal's body highly reflective. At medium depths at sea, light comes from above, so

16756-477: The sides of a tank. The Peltier plate panels are heated and cooled to match either the vehicle's surroundings (crypsis), or an object such as a car (mimesis), when viewed in infrared. Countershading uses graded colour to counteract the effect of self-shadowing, creating an illusion of flatness. Self-shadowing makes an animal appear darker below than on top, grading from light to dark; countershading 'paints in' tones which are darkest on top, lightest below, making

16898-462: The speckled wood, Pararge aegeria , minimise their shadows when perched by closing the wings over their backs, aligning their bodies with the sun, and tilting to one side towards the sun, so that the shadow becomes a thin inconspicuous line rather than a broad patch. Similarly, some ground-nesting birds, including the European nightjar , select a resting position facing the sun. Eliminating shadow

17040-420: The spinner so it was blowing rearward along the cylinder heads. To provide enough airflow, an internal cone was placed in the centre of the hole, over the propeller hub, which was intended to compress the airflow and allow a smaller opening to be used. In theory, the tight-fitting cowling also provided some thrust due to the compression and heating of air as it flowed through the cowling. The eventual choice of

17182-548: The summer of 1942, when the improved Spitfire Mk. IX was introduced. In June 1942, Oberleutnant Armin Faber of JG 2 landed his Fw 190 A-3 at a British airfield, allowing the RAF to test the Mk. IX against the 190 and learn tactics to counter it. A 0.40 km (99-acre) Focke-Wulf plant east of Marienburg was bombed by the Eighth Air Force on 9 October 1944. In addition, one of the most important sub-contractors for

17324-722: The summer to white in the winter; the Arctic fox is the only species in the dog family to do so. However, Arctic hares which live in the far north of Canada , where summer is very short, remain white year-round. The principle of varying coloration either rapidly or with the changing seasons has military applications. Active camouflage could in theory make use of both dynamic colour change and counterillumination. Simple methods such as changing uniforms and repainting vehicles for winter have been in use since World War II. In 2011, BAE Systems announced their Adaptiv infrared camouflage technology. It uses about 1,000 hexagonal panels to cover

17466-835: The target's speed, range, and heading. During and after the Second World War , a variety of camouflage schemes were used for aircraft and for ground vehicles in different theatres of war. The use of radar since the mid-20th century has largely made camouflage for fixed-wing military aircraft obsolete. Non-military use of camouflage includes making cell telephone towers less obtrusive and helping hunters to approach wary game animals. Patterns derived from military camouflage are frequently used in fashion clothing, exploiting their strong designs and sometimes their symbolism. Camouflage themes recur in modern art, and both figuratively and literally in science fiction and works of literature. In ancient Greece, Aristotle (384–322 BC) commented on

17608-470: The theory to a fantastic extreme in an endeavour to make it cover almost every type of coloration in the animal kingdom." Cott built on Thayer's discoveries, developing a comprehensive view of camouflage based on "maximum disruptive contrast", countershading and hundreds of examples. The book explained how disruptive camouflage worked, using streaks of boldly contrasting colour, paradoxically making objects less visible by breaking up their outlines. While Cott

17750-458: The thinner air at higher altitudes. The wings spanned 9.5 m (31 ft 2 in) and had an area of 15 m (160 sq ft). The wing was designed using the NACA 23015.3 airfoil at the root and the NACA 23009 airfoil at the tip. Earlier aircraft designs generally featured canopies consisting of small plates of perspex (also known as Plexiglas) in a metal "greenhouse" framework, with

17892-539: The top of the canopy even with the rear fuselage; this was true of the IJNAS Mitsubishi A6M Zero , whose otherwise "all-around view" canopy was still heavily framed. This design considerably limited visibility, especially to the rear. The introduction of vacuum forming , led to the creation of the " bubble canopy " which was largely self-supporting, and could be mounted over the cockpit, offering greatly improved all-round visibility. Tank's design for

18034-602: The twin cannon replaced by the MK 108 30mm autocannon in the outer wing, which then became the A-6/R2. The cannons were blowback-operated, had electric ignition, and were belt fed. The 30mm MK 108 was simple to make and its construction was economical; the majority of its components consisted of just pressed sheet metal stampings. In the A-6/R4, the GM-1 ( nitrous oxide ) Boost was added for

18176-399: The undercarriage was operated by push buttons controlling electric motors in the wings, and was kept in position by electric up and down-locks. The armament was also loaded and fired electrically. Tank believed that service use would prove that electrically powered systems were more reliable and more rugged than hydraulics, electric lines being much less prone to damage from enemy fire. Like

18318-404: The unsuccessful He 100 and He 112. Although the Bf 109 was an extremely competitive fighter, the Ministry was worried that future foreign designs might outclass it, and wanted to have new aircraft under development to meet these possible challenges. Tank responded with a number of designs, most powered by a liquid-cooled inline engine. However, it was not until a design was presented using

18460-407: The war. The Fw 190 was well-liked by its pilots. Some of the Luftwaffe's most successful fighter aces claimed many of their kills while flying it, including Otto Kittel , Walter Nowotny and Erich Rudorffer . The Fw 190 had greater firepower than the Bf 109 and, at low to medium altitude, superior manoeuvrability, in the opinion of German pilots who flew both fighters. It was regarded as one of

18602-508: The wavelength of visible light. A familiar example is the transparency of the lens of the vertebrate eye , which is made of the protein crystallin , and the vertebrate cornea which is made of the protein collagen . Other structures cannot be made transparent, notably the retinas or equivalent light-absorbing structures of eyes – they must absorb light to be able to function. The camera -type eye of vertebrates and cephalopods must be completely opaque. Finally, some structures are visible for

18744-479: The world at the time we began work on the Fw 190, could both be summed up as a very large engine on the front of the smallest possible airframe; in each case armament had been added almost as an afterthought. These designs, both of which admittedly proved successful, could be likened to racehorses: given the right amount of pampering and easy course, they could outrun anything. But the moment the going became tough they were liable to falter. During World War I, I served in

18886-571: The year after construction began on facilities. A2 measured 4 m (13 ft 1 in) long and had a test section 2.8 m (9 ft 2 in) in diameter (coated with Keratylene to keep the flow smooth), capable of generating test speeds (depending on the model's scale ) of between Mach 1 and 1.2. It was driven by a pair of 600 kW (800 hp) DC electric motors , and fitted with interferometer and striation gear for study of flow patterns. Begun in 1937, it first ran in 1939. It did, however, suffer with problems of vibration, leading

19028-454: Was Nachtjagdgruppe 10 ( NJGr 10 ), which used Fw 190 A-4/R11s through to A-8/R11s; Fw 190s modified to carry FuG ( Funkgerät ) 217 or FuG 218 radar mid-VHF band equipment. The appearance of United States Army Air Forces heavy bombers caused a problem for the German fighter force. The Boeing B-17 Flying Fortress in particular was especially durable, and the armament of

19170-412: Was accomplished by tilting the entire horizontal tailplane with an electric motor, with an angle of incidence ranging from −3° to +5°. Another aspect of the new design was the extensive use of electrically powered equipment instead of the hydraulic systems used by most aircraft manufacturers of the time. On the first two prototypes, the main landing gear was hydraulic. Starting with the third prototype,

19312-688: Was expanded to become Jagdgeschwader 300 (JG 300, or Fighter Wing 300), JG 301 and JG 302. All three units initially continued borrowing their aircraft from day fighter units. The day fighter units began to protest at the numbers of their aircraft which were being written off because of the hazards of night operations; the numbers soared with the onset of winter, with pilots often being forced to bail-out through being unable to find an airfield at which to land safely. Crash landings were also frequent. Eventually all three Wilde Sau units received their own aircraft, which were often modified with exhaust dampers and blind-flying radio equipment. Another unit

19454-682: Was identified as a principle of military camouflage during the Second World War . Many prey animals have conspicuous high-contrast markings which paradoxically attract the predator's gaze. These distractive markings may serve as camouflage by distracting the predator's attention from recognising the prey as a whole, for example by keeping the predator from identifying the prey's outline. Experimentally, search times for blue tits increased when artificial prey had distractive markings. Some animals actively seek to hide by decorating themselves with materials such as twigs, sand, or pieces of shell from their environment, to break up their outlines, to conceal

19596-464: Was made obsolete by radar , and neither diffused lighting camouflage nor Yehudi lights entered active service. Many marine animals that float near the surface are highly transparent , giving them almost perfect camouflage. However, transparency is difficult for bodies made of materials that have different refractive indices from seawater. Some marine animals such as jellyfish have gelatinous bodies, composed mainly of water; their thick mesogloea

19738-498: Was more systematic and balanced in his view than Thayer, and did include some experimental evidence on the effectiveness of camouflage, his 500-page textbook was, like Thayer's, mainly a natural history narrative which illustrated theories with examples. Experimental evidence that camouflage helps prey avoid being detected by predators was first provided in 2016, when ground-nesting birds ( plovers and coursers ) were shown to survive according to how well their egg contrast matched

19880-481: Was not convinced of this, having witnessed the successful use of radial engines by the U.S. Navy , and felt a properly streamlined installation would eliminate this problem. As to the rest of the design philosophy, Tank wanted something more than an aircraft built only for speed. He outlined the reasoning: The Messerschmitt 109 [ sic ] and the British Spitfire, the two fastest fighters in

20022-681: Was powered by a pair of 6 MW (8,000 hp; 8,200 PS). The A9 building housed a pair of supersonic wind tunnels, each driven by a 4 MW (5,400 hp; 5,400 PS) motor, with a maximum speed of Mach 1.5, but a test section diameter of only 80 cm (12 in). Along with direct aerodynamic research, LFA did testing on materials (though not, apparently, of parts) and on aircraft engines. The engine work included testing of turbine and turbine blade shapes, ceramic turbine blades, cooling of turbine blades (including liquid cooling), bearings, detonation , and several types of heat exchangers , among other things. The test centre assisted

20164-464: Was the background thinking behind the Focke-Wulf 190; it was not to be a racehorse but a Dienstpferd , a cavalry horse. The hottest points on any air-cooled engine are the cylinder heads, located around the circumference of a radial engine. In order to provide sufficient air to cool the engine, airflow had to be maximized at this outer edge. This was normally accomplished by leaving the majority of

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