Viola is a genus of flowering plants in the violet family Violaceae. It is the largest genus in the family, containing between 600 species. Most species are found in the temperate Northern Hemisphere; some Viola species are perennial plants, some are annual plants, a few are small shrubs. A large number of species and cultivars are grown in gardens for their ornamental flowers. In horticulture the term pansy is used for those multi-colored, large-flowered cultivars which are raised annually or biennially from seed and used extensively in bedding; the terms viola and violet are reserved for small-flowered annuals or perennials, including the wild species. Viola have heart-shaped, scalloped leaves, though a number have palmate leaves or other shapes; the vast majority of Viola species are herbaceous, a substantial number are acaulescent in habit - meaning they lack any noticeable stems and the foliage and flowers appear to rise from the ground. The simple leaves of plants with either habit are arranged alternately.
Plants always have leaves with stipules that are leaf-like. The flowers of the vast majority of the species are zygomorphic with bilateral symmetry; the flowers are formed from five petals. The shape of the petals and placement defines many species, for example, some species have a "spur" on the end of each petal while most have a spur on the lower petal. Solitary flowers end long stalks with a pair of bracteoles; the flowers have five sepals that persist after blooming, in some species the sepals enlarge after blooming. The flowers have five free stamens with short filaments that are oppressed against the ovary, only the lower two stamens have nectary spurs that are inserted on the lowest petal into the spur or a pouch; the flower styles are thickened near the top and the stigmas are head-like, narrowed or beaked. The flowers have a superior ovary with one cell. Viola are most spring blooming with chasmogamous flowers with well-developed petals pollinated by insects. Many species produce self-pollinated cleistogamous flowers in summer and autumn that do not open and lack petals.
In some species the showy chasmogamous flowers are infertile. After flowering, fruit capsules are produced. On drying, the capsules may eject seeds with considerable force to distances of several meters; the nutlike seeds have straight embryos, flat cotyledons, soft fleshy endosperm, oily. The seeds of some species are dispersed by ants. Flower colors vary in the genus, ranging from violet, through various shades of blue, yellow and cream, whilst some types are bicolored blue and yellow. Flowering is profuse, may last for much of the spring and summer. One quirk of some Viola is the elusive scent of their flowers. See List of Viola species for a more complete list. Note: Neither Saintpaulia nor Erythronium dens-canis are related to the true Viola; the genus includes dog violets, a group of scentless species which are the most common Viola in many areas, sweet violet, many other species whose common name includes the word "violet". Several species are known as pansies, including the yellow pansy of the Pacific coast.
Common blue violet Viola sororia is the state flower of Wisconsin, Rhode Island and New Jersey. Australia is home to a number of Viola species, including Viola hederacea, Viola betonicifolia and Viola banksii, first collected by Joseph Banks and Daniel Solander on the Cook voyage to Botany Bay. One fossil seed of †Viola rimosa has been extracted from borehole samples of the Middle Miocene fresh water deposits in Nowy Sacz Basin, West Carpathians, Poland. Cultivars of Viola cornuta, Viola cucullata, Viola odorata, are grown from seed. Other species grown include Viola labradorica, Viola pedata, Viola rotundifolia; the modern garden pansy is a plant of complex hybrid origin involving at least three species, V. tricolor, V. altaica, V. lutea. The hybrid horned pansy originates from hybridization involving Viola cornuta. In 2005 in the United States, Viola cultivars were one of the top three bedding plant crops and 111 million dollars worth of flats of Viola were produced for the bedding flower market.
Pansies and violas used for bedding are raised from seed, F1 hybrid seed strains have been developed which produce compact plants of reasonably consistent flower coloring and appearance. Bedding plants are discarded after one growing season. There are hundreds of perennial violetta cultivars. Violettas can be distinguished from violas by the lack of ray markings on their petals; the following cultivars, of mixed or uncertain parentage, have gained the Royal Horticultural Society's Award of Garden Merit:-'Aspasia"Clementina"Huntercombe Purple"Moonlight
Berberis microphylla, common name box-leaved barberry and Magellan barberry, in Spanish calafate and michay and other names, is an evergreen shrub, with simple, shiny box-like leaves. The Calafate is a symbol of Patagonia; the bush grows to a height of 1.0 to 1.5 m. It has many arching branches, each covered in many tripartite spines; the bush has many small yellow flowers in summer. Its edible blue-black berries are harvested for jams, but are eaten fresh too - a legend tells that anyone who eats a calafate berry will be certain to return to Patagonia; the calafate is grown commercially for its fruit, potential medical uses and as a garden plant or bonsai. Its wood is used to make a red dye; the cultivar Berberis microphylla'Nana' is available as a garden shrub, is used in commercial plantings as a low spiny hedge to discourage intruders, but it does not fruit. Berberis microphylla should not be confused with Mahonia microphylla T. S. Ying & GR. Long, native to China
An estuary is a enclosed coastal body of brackish water with one or more rivers or streams flowing into it, with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments, they are subject both to marine influences—such as tides and the influx of saline water—and to riverine influences—such as flows of fresh water and sediment. The mixing of sea water and fresh water provide high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world. Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when the sea level began to rise about 10,000–12,000 years ago. Estuaries are classified according to their geomorphological features or to water-circulation patterns, they can have many different names, such as bays, lagoons, inlets, or sounds, although some of these water bodies do not meet the above definition of an estuary and may be saline.
The banks of many estuaries are amongst the most populated areas of the world, with about 60% of the world's population living along estuaries and the coast. As a result, many estuaries suffer degradation from a variety of factors including: sedimentation from soil erosion from deforestation and other poor farming practices; the word "estuary" is derived from the Latin word aestuarium meaning tidal inlet of the sea, which in itself is derived from the term aestus, meaning tide. There have been many definitions proposed to describe an estuary; the most accepted definition is: "a semi-enclosed coastal body of water, which has a free connection with the open sea, within which sea water is measurably diluted with freshwater derived from land drainage". However, this definition excludes a number of coastal water bodies such as coastal lagoons and brackish seas. A more comprehensive definition of an estuary is "a semi-enclosed body of water connected to the sea as far as the tidal limit or the salt intrusion limit and receiving freshwater runoff.
This broad definition includes fjords, river mouths, tidal creeks. An estuary is a dynamic ecosystem having a connection to the open sea through which the sea water enters with the rhythm of the tides; the sea water entering the estuary streams. The pattern of dilution varies between different estuaries and depends on the volume of fresh water, the tidal range, the extent of evaporation of the water in the estuary. Drowned river valleys are known as coastal plain estuaries. In places where the sea level is rising relative to the land, sea water progressively penetrates into river valleys and the topography of the estuary remains similar to that of a river valley; this is the most common type of estuary in temperate climates. Well-studied estuaries include the Severn Estuary in the United Kingdom and the Ems Dollard along the Dutch-German border; the width-to-depth ratio of these estuaries is large, appearing wedge-shaped in the inner part and broadening and deepening seaward. Water depths exceed 30 m.
Examples of this type of estuary in the U. S. are the Hudson River, Chesapeake Bay, Delaware Bay along the Mid-Atlantic coast, Galveston Bay and Tampa Bay along the Gulf Coast. Bar-built estuaries are found in place where the deposition of sediment has kept pace with rising sea level so that the estuaries are shallow and separated from the sea by sand spits or barrier islands, they are common in tropical and subtropical locations. These estuaries are semi-isolated from ocean waters by barrier beaches. Formation of barrier beaches encloses the estuary, with only narrow inlets allowing contact with the ocean waters. Bar-built estuaries develop on sloping plains located along tectonically stable edges of continents and marginal sea coasts, they are extensive along the Atlantic and Gulf coasts of the U. S. in areas with active coastal deposition of sediments and where tidal ranges are less than 4 m. The barrier beaches that enclose bar-built estuaries have been developed in several ways: building up of offshore bars by wave action, in which sand from the sea floor is deposited in elongated bars parallel to the shoreline, reworking of sediment discharge from rivers by wave and wind action into beaches, overwash flats, dunes, engulfment of mainland beach ridges due to sea level rise and resulting in the breaching of the ridges and flooding of the coastal lowlands, forming shallow lagoons, elongation of barrier spits from the erosion of headlands due to the action of longshore currents, with the spits growing in the direction of the littoral drift.
Barrier beaches form in shallow water and are parallel to the shoreline, resulting in long, narrow estuaries. The average water depth is less than 5 m, exceeds 10 m. Examples of bar-built estuaries are Barnegat Bay, New Jersey. Fjords were formed where pleistocene glaciers deepened and widened existing river valleys so that they become U-shaped in cross s
The guanaco is a camelid native to South America related to the llama. Its name comes from the Quechua word huanaco. Young guanacos are called chulengos. Guanacos inhabit the steppes and mountainous regions of South America, they are found in the altiplano of Peru and Chile, in Patagonia, with a small population in Paraguay. In Argentina and Chile, they are more numerous in Patagonian regions, as well as in places such as the Torres del Paine National Park, Isla Grande de Tierra del Fuego. In these areas, they have more robust populations, since grazing competition from livestock is limited. Estimates, as of 2011, place their numbers at 400,000 to 600,000. A small introduced population exists on Staats Island in the Falkland Islands, with a population of around 400 as of 2003. Guanacos live in herds composed of females, their young, a dominant male. Bachelor males form separate herds. While reproductive groups tend to remain small containing no more than 10 adults, bachelor herds may contain as many as 50 males.
When they feel threatened, guanacos alert the herd to flee with a bleating call. The male runs behind the herd to defend them, they can run at 56 km per hour over steep and rocky terrain. They are excellent swimmers. A guanaco's typical lifespan is 20 to 25 years; some guanacos live in the Atacama Desert. A mountainous coastline running parallel to the desert enables them to survive in what are called "fog oases" or lomas. Where the cool water touches the hotter land, the air above the desert is cooled, creating a fog and thus, water vapor. Winds carry the fog across the desert, where cacti catch the water droplets and lichens that cling to the cacti soak it in like a sponge. Guanacos eat the cacti flowers and the lichens. Natural predators of the guanaco include foxes. Guanacos spit when threatened. Mating season occurs between November and February, during which males fight violently to establish dominance and breeding rights. Eleven-and-a-half months a single chulengo is born. Chulengos are able to walk after birth.
Male chulengos are chased off from the herd by the dominant male around one year of age. Although the species is still considered wild, around 300 guanacos are in US zoos and around 200 are registered in private herds. Guanacos have long been thought to be the parent species of the domesticated llama, confirmed via molecular phylogenetic analysis in 2001, although the analysis found that domestic llamas had experienced considerable cross-hybridization with alpacas, which are descended from the wild vicuña. Lama guanicoe guanicoe Lama guanicoe cacsilensis Lama guanicoe voglii Lama guanicoe huanacus The guanaco stands between 1.0 and 1.2 m at the shoulder, weighs 90 to 140 kg. Its colour varies little, ranging from a light brown to dark cinnamon and shading to white underneath. Guanacos have small, straight ears. Guanacos are one of the largest wild mammal species found in South America, along with the manatee, the Amazon river dolphin, the tapir, the jaguar; the guanaco has thick skin on its neck, a trait found in its domestic counterpart, the llama and in its relatives, the wild vicuña and domesticated alpaca.
This protects its neck from predator attacks. Bolivians use the neck-skin of these animals to make shoes and pounding the skin to be used for the soles. In Chile, hunting is allowed only in Tierra del Fuego, where the only population not classified as endangered in the country resides. Between 2007 and 2012, 13,200 guanacos were hunted in Tierra del Fuego. Guanacos are found at high altitudes, up to 4,000 meters above sea level, except in Patagonia, where the southerly latitude means ice covers the vegetation at these altitudes. For guanacos to survive in the low oxygen levels found at these high altitudes, their blood is rich in red blood cells. A teaspoon of guanaco blood contains about 68 billion red blood cells – four times that of a human. Guanaco fiber is prized for its soft, warm feel and is found in luxury fabric; the guanaco's soft wool is valued second only to that of the vicuña. The pelts from the calves, are sometimes used as a substitute for red fox pelts, because the texture is difficult to differentiate.
Like their domestic descendant, the llama, the guanaco is double-coated with coarse guard hairs and a soft undercoat, the hairs of which are about 16–18 µ in diameter and comparable to the best cashmere. Llama Alpaca Vicuña
The Loaísa expedition was a 16th-century voyage of discovery to the Pacific Ocean, commanded by Garcia Jofre de Loaísa and ordered by King Charles I of Spain to colonize the Spice Islands in the East Indies. The seven-ship fleet sailed from La Coruña in July 1525 and became the second naval expedition to cross the Pacific Ocean in history, after Magellan-Elcano's voyage; the expedition resulted in the discovery of the Sea of Hoces, south of Cape Horn and, the Marshall Islands in the Pacific. One ship arrived in the Spice Islands on New Year's Day of 1527. De Loaísa's expedition was conceived both as a voyage of discovery; the Victoria, a vessel from Magellan's expedition to the Pacific, had returned to Spain in 1522 with word that her sister ship the Trinidad had last been seen attempting to return home by sailing east from the Spice Islands to South America. De Loaísa was ordered to seek Trinidad, or news of her fate, by voyaging along her expected return route to Spain. Failing this he was to locate and colonise Magellan's Spice Islands, to bring back news of the semi-mythical land of Ophir which Spanish scholars believed may be somewhere near China.
- For this purpose, de Loaísa was assigned seven vessels and a total of 450 men including tradesmen and administrators for the Spice Islands settlement. The expedition set sail from Corunna on July 24, 1525, it consisted of seven ships, Santa María de la Victoria, Sancti Spiritus, San Gabriel, Santa María del Parral and San Lesmes and a patache, Santiago. De Loaísa was named captain along with Juan Sebastián Elcano, who had reached the Spice Islands in 1521 during the Magellan expedition; the fleet headed southwest to the Canary Islands and south along the African coastline. In November 1525 de Loaísa moved west across the Atlantic to Brazil, reaching the Patagonian shore in January 1526. There was no sign of Trinidad, de Loaísa decided to abandon the search for her and continue instead to the Spice Islands; however the weather was poor, over the next several weeks, in high winds while trying to enter the Strait of Magellan, the ships alternately gathered and dispersed. Two ships, Sancti Spiritus and Anunciada were wrecked, one, San Gabriel tacked into the Atlantic and deserted the expedition.
The San Lesmes under the captaincy of Francisco de Hoces was driven south along the coast to a latitude of 57°, where the crew noted "an end of land" which may have been the first European sighting of Cape Horn. After some difficulty Hoces was able to steer his galleon northward once more, rejoining the other three vessels that remained with the expedition. On 26 May 1526, this diminished fleet of four ships, passed through the Strait and entered the Pacific; the bad weather which had scattered de Loaísa's fleet continued in the Pacific. The four remaining vessels lost sight of each other in the heavy rain and were unable to regroup when the storm passed on 1 June; the Santiago sailed for north, in a 10,000-kilometre voyage, reached the Pacific coast of Mexico in July 1526, achieving the first navigation from Europe to the western coast of North America. San Lesmes disappeared entirely. Twentieth century speculation suggests she may have run aground in the Tuamotus, either on the island of Anaa where a 1774 expedition found a cross erected on the beach, or off the Amanu atoll where an old Spanish cannon was found.
The third ship, Santa María del Parral, sailed the Pacific to Sangir off the northern coast of Sulawesi, where the ship was beached and its crew were variously killed or enslaved by the natives. Four survivors were rescued in 1528 by another Spanish expedition coming from Mexico; the last galleon, Santa Maria de la Victoria, was the only ship to reach the Spice Islands, landing in September 1526. Loaísa himself died of scurvy on July 30, 1526, Elcano a few days and Alonso de Salazar three weeks after that. Yñigez reached the islands of Visayas and Mindanao in the Philippines and the Moluccas, but died of food poisoning. Only Andrés de Urdaneta and 24 other men survived to land in the Spice Islands, they returned to Spain in 1536 in the Portuguese India Armada and under Portuguese guard to complete second world circumnavigation in History. The fate of the San Lesmes is explored in Greg Scowen's conspiracy thriller The Spanish Helmet, based on Robert Langdon's theory that the lost vessel made its way to, discovered, New Zealand.
History of the Philippines Berguno, Jorge. "The South and Mid-Pacific Voyages". In Hardy, John. European Voyaging towards Australia. Australian Academy of the Humanities. ISBN 0909897190. Kelsey, Harry. "Finding the Way Home: Spanish Exploration of the Round-Trip Route across the Pacific Ocean". The Western Historical Quarterly. United States: Utah State University. 17. JSTOR 969278. Nowell, Charles E.. "The Loaisa Expedition and the Ownership of the Moluccas". Pacific Historical Review. United States: University of California Press. 5. JSTOR 3632888. Landín Carrasco, Amancio. España en el mar. Padrón de descubridores. Madrid: Editorial Naval ISBN 84-7341-078-5 Oyarzun, Javier. Expediciones españolas al Estrecho de Magallanes y Tierra de Fuego. Madrid: Ediciones Cultura Hispánica ISBN 84-7232-130-4. "Expedición de Loaysa ó Loaisa 1524-1536" Historia Naval de España Philip & Waine, Stefanie. The people from the horizon. London: Mclaren Publishing ISBN 0-947889-05-1 "Expedition of García de Loaisa 1525-26." In The Philippine Islands, 1493-1898, edited and annotated by Emma Helen Blair and James Alexander Robertson.
Cleveland, Ohio: A. H. Clark Company, 1903-9. Vol. 2, 1529-1561. Pp. 25–35
The Falklands War known as the Falklands Conflict, Falklands Crisis, Malvinas War, South Atlantic Conflict, the Guerra del Atlántico Sur, was a ten-week war between Argentina and the United Kingdom over two British dependent territories in the South Atlantic: the Falkland Islands, its territorial dependency, the South Georgia and the South Sandwich Islands. It began on Friday, 2 April 1982, when Argentina invaded and occupied the Falkland Islands in an attempt to establish the sovereignty it had claimed over them. On 5 April, the British government dispatched a naval task force to engage the Argentine Navy and Air Force before making an amphibious assault on the islands; the conflict lasted 74 days and ended with the Argentine surrender on 14 June 1982, returning the islands to British control. In total, 649 Argentine military personnel, 255 British military personnel, three Falkland Islanders died during the hostilities; the conflict was a major episode in the protracted confrontation over the territories' sovereignty.
Argentina asserted that the islands are Argentine territory, the Argentine government thus characterised its military action as the reclamation of its own territory. The British government regarded the action as an invasion of a territory, a Crown colony since 1841. Falkland Islanders, who have inhabited the islands since the early 19th century, are predominantly descendants of British settlers, favour British sovereignty. Neither state declared war, although both governments declared the Islands a war zone. Hostilities were exclusively limited to the territories under dispute and the area of the South Atlantic where they lie; the conflict has had a strong effect in both countries and has been the subject of various books, articles and songs. Patriotic sentiment ran high in Argentina, but the outcome prompted large protests against the ruling military government, hastening its downfall. In the United Kingdom, the Conservative government, bolstered by the successful outcome, was re-elected with an increased majority the following year.
The cultural and political effect of the conflict has been less in the UK than in Argentina, where it remains a common topic for discussion. Diplomatic relations between the United Kingdom and Argentina were restored in 1989 following a meeting in Madrid, at which the two governments issued a joint statement. No change in either country's position regarding the sovereignty of the Falkland Islands was made explicit. In 1994, Argentina's claim to the territories was added to its constitution. In the period leading up to the war—and, in particular, following the transfer of power between the military dictators General Jorge Rafael Videla and General Roberto Eduardo Viola late in March 1981—Argentina had been in the midst of a devastating economic stagnation and large-scale civil unrest against the military junta, governing the country since 1976. In December 1981 there was a further change in the Argentine military regime, bringing to office a new junta headed by General Leopoldo Galtieri, Air Brigadier Basilio Lami Dozo and Admiral Jorge Anaya.
Anaya was the main architect and supporter of a military solution for the long-standing claim over the islands, calculating that the United Kingdom would never respond militarily. By opting for military action, the Galtieri government hoped to mobilise the long-standing patriotic feelings of Argentines towards the islands, thus divert public attention from the country's chronic economic problems and the regime's ongoing human rights violations of the Dirty War; such action would bolster its dwindling legitimacy. The newspaper La Prensa speculated in a step-by-step plan beginning with cutting off supplies to the islands, ending in direct actions late in 1982, if the UN talks were fruitless; the ongoing tension between the two countries over the islands increased on 19 March when a group of Argentine scrap metal merchants raised the Argentine flag at South Georgia Island, an act that would be seen as the first offensive action in the war. The Royal Navy ice patrol vessel HMS Endurance was dispatched from Stanley to South Georgia on the 25th in response.
The Argentine military junta, suspecting that the UK would reinforce its South Atlantic Forces, ordered the invasion of the Falkland Islands to be brought forward to 2 April. The UK was taken by surprise by the Argentine attack on the South Atlantic islands, despite repeated warnings by Royal Navy captain Nicholas Barker and others. Barker believed that Defence Secretary John Nott's 1981 review had sent a signal to the Argentines that the UK was unwilling, would soon be unable, to defend its territories and subjects in the Falklands. On 2 April 1982, Argentine forces mounted amphibious landings, known as Operation Rosario, on the Falkland Islands; the invasion was met with a nominal defence organised by the Falkland Islands' Governor Sir Rex Hunt, giving command to Major Mike Norman of the Royal Marines. The events of the invasion included the landing of Lieutenant Commander Guillermo Sanchez-Sabarots' Amphibious Commandos Group, the attack on Moody Brook barracks, the engagement between the troops of Hugo Santillan and Bill Trollope at Stanley, the final engagement and surrender at Government House.
Word of the invasion first reached the UK from Argentine sources. A Ministry of Defence operative in London had a short telex conversation with Governor Hunt's telex operator, who confirmed th
Douglas A-4 Skyhawk
The Douglas A-4 Skyhawk is a single seat subsonic carrier-capable attack aircraft developed for the United States Navy and United States Marine Corps in the early 1950s. The delta winged, single turbojet engined Skyhawk was designed and produced by Douglas Aircraft Company, by McDonnell Douglas, it was designated A4D under the U. S. Navy's pre-1962 designation system; the Skyhawk is a lightweight aircraft with a maximum takeoff weight of 24,500 pounds and has a top speed of more than 670 miles per hour. The aircraft's five hardpoints support a variety of missiles and other munitions, it is capable of carrying a bomb load equivalent to that of a World War II–era Boeing B-17 bomber, can deliver nuclear weapons using a low-altitude bombing system and a "loft" delivery technique. The A-4 was powered by the Wright J65 turbojet engine. Skyhawks played key roles in the Vietnam War, the Yom Kippur War, the Falklands War. Sixty years after the aircraft's first flight in 1954, some of the 2,960 produced remain in service with the Argentine Air Force.
The Skyhawk was designed by Douglas Aircraft's Ed Heinemann in response to a U. S. Navy call for a jet-powered attack aircraft to replace the older Douglas AD Skyraider. Heinemann opted for a design that would minimize its size and complexity; the result was an aircraft. It had a wing so compact; the first 500 production examples cost an average of $860,000 each, less than the Navy's one million dollar maximum. The diminutive Skyhawk soon received the nicknames "Scooter", "Kiddiecar", "Bantam Bomber", "Tinker Toy Bomber", and, on account of its speed and nimble performance, "Heinemann's Hot-Rod"; the XA4D-1 prototype set a world speed record of 695.163 mph on October 15, 1955. The aircraft is of conventional post-World War II design, with a low-mounted delta wing, tricycle undercarriage, a single turbojet engine in the rear fuselage, with two air intakes on the fuselage sides; the tail is with the horizontal stabilizer mounted above the fuselage. Armament consisted of two 20 mm Colt Mk 12 cannons, one in each wing root, with 100 rounds per gun, plus a large variety of bombs and missiles carried on a hardpoint under the fuselage centerline and hardpoints under each wing.
The short-span delta wing did not require the complexity of wingtip folding, saving an estimated 200 pounds. Its spars were machined from a single forging; the leading edge slats were designed to drop automatically at the appropriate speed by gravity and air pressure, saving weight and space by omitting actuation motors and switches. The main undercarriage did not penetrate the main wing spar, designed so that when retracted only the wheel itself was inside the wing and the undercarriage struts were housed in a fairing below the wing, thus the wing structure was lighter with the same overall strength. The rudder was constructed of a single panel reinforced with external ribs; the turbojet engine was accessed for service or replacement by removing the aft section of the fuselage and sliding out the engine. This obviated the need for access doors with their hinges and latches further reducing weight and complexity; this is the opposite of what can happen in aircraft design where a small weight increase in one area leads to a compounding increase in weight in other areas to compensate, creating a demand for more powerful, heavier engines, larger wing and empennage area, so on in a vicious circle.
The A-4 pioneered the concept of "buddy" air-to-air refueling. This allows the aircraft to supply others of the same type, reducing the need for dedicated tanker aircraft—a particular advantage for small air arms or when operating in remote locations; this allows for improved operational flexibility and reassurance against the loss or malfunction of tanker aircraft, though this procedure reduces the effective combat force on board the carrier. A designated supply A-4 would mount a center-mounted "buddy store", a large external fuel tank with a hose reel in the aft section and an extensible drogue refueling bucket; this aircraft was launched first. Attack aircraft would be armed to the maximum and given as much fuel as was allowable by maximum takeoff weight limits, far less than a full tank. Once airborne, they would proceed to top off their fuel tanks from the tanker using the A-4's fixed refueling probe on the starboard side of the aircraft nose, they could sortie with both full armament and fuel loads.
The A-4 was used for refueling in U. S. service after the KA-3 Skywarrior tanker became available aboard the larger carriers. The versatility of the capability and the retirement of the Skywarrior meant that the Boeing F/A-18E/F Super Hornet now includes this capability; the A-4 was designed to be able to make an emergency landing, in the event of a hydraulic failure, on the two drop tanks nearly always carried by these aircraft. Such landings resulted in only minor damage to the nose of the aircraft which could be repaired in less than an hour; the Navy issued a contract for the type on 12 June 1952, the first prototype first flew from Edwards Air Force Base, California on 22 June 1954. Deliveries to Navy and Marine Corps squadrons commenced in late 1956; the Skyhawk remained in production until 1979, with 2,960 aircraft built, including 555 two-seat trainers