Aviation

what is aviation?

The word aviation was coined by the French writer and former naval officer Gabriel La Landelle in 1863. He derived the term from the verb avier (an unsuccessful neologism for "to fly"), itself derived from the Latin word avis ("bird") and the suffix -ation.

History

There are early legends of human flight such as the stories of Icarus in Greek myth and Jamshid and Shah Kay Kāvus in Persian myth. Later, somewhat more credible claims of short-distance human flights appear, such as the flying automaton of Archytas of Tarentum (428–347 BC), 

the winged flights of Abbas Ibn Firnas(810–887), Eilmer of Malmesbury (11th century), and the hot-air Passarola of Bartholomeu Lourenço de Gusmão (1685–1724).

In 1799, Sir George Cayley set forth the concept of the modern airplane as a fixed-wing flying machine with separate systems for lift, propulsion, and control.Early dirigible developments included machine-powered propulsion (Henri Giffard, 1852), rigid frames (David Schwarz, 1896) and improved speed and maneuverability (Alberto Santos-Dumont, 1901).

There are many competing claims for the earliest powered, heavier-than-air flight. The first recorded powered flight was carried out by Clément Ader on October 9, 1890 in his bat-winged, fully self-propelled fixed-wing aircraft, the Ader Éole. It was reportedly the first manned, powered, heavier-than-air flight of a significant distance (50 m (160 ft)) but insignificant altitude from level ground. Seven years later, on 14 October 1897, Ader's Avion III was tested without success in front of two officials from the French War ministry. The report on the trials was not publicized until 1910, as they had been a military secret. In November 1906 Ader claimed to have made a successful flight on 14 October 1897, achieving an "uninterrupted flight" of around 300 metres (980 feet). Although widely believed at the time, these claims were later discredited.

The Wright brothers made the first successful powered, controlled and sustained airplane flight on December 17, 1903, a feat made possible by their invention of three-axis control. Only a decade later, at the start of World War I, heavier-than-air powered aircraft had become practical for reconnaissance, artillery spotting, and even attacks against ground positions.

Aircraft began to transport people and cargo as designs grew larger and more reliable. The Wright brothers took aloft the first passenger, Charles Furnas, one of their mechanics, on May 14, 1908.

During the 1920s and 1930s great progress was made in the field of aviation, including the first transatlantic flight of Alcock and Brown in 1919, Charles Lindbergh's solo transatlantic flight in 1927, and Charles Kingsford Smith's transpacific flight the following year. One of the most successful designs of this period was the Douglas DC-3, which became the first airliner to be profitable carrying passengers exclusively, starting the modern era of passenger airline service. By the beginning of World War II, many towns and cities had built airports, and there were numerous qualified pilots available. The war brought many innovations to aviation, including the first jetaircraft and the first liquid-fueled rockets.

Air traffic control

Air traffic control (ATC) involves communication with aircraft to help maintain separation – that is, they ensure that aircraft are sufficiently far enough apart horizontally or vertically for no risk of collision. Controllers may co-ordinate position reports provided by pilots, or in high traffic areas (such as the United States) they may use radar to see aircraft positions.

There are generally four different types of ATC:

• center controllers, who control aircraft en route between airports
• control towers (including tower, ground control, clearance delivery, and other services), which control aircraft within a small distance (typically 10–15 km horizontal, and 1,000 m vertical) of an airport.
• oceanic controllers, who control aircraft over international waters between continents, generally without radar service.
• terminal controllers, who control aircraft in a wider area (typically 50–80 km) around busy airports.

ATC is especially important for aircraft flying under instrument flight  rules (IFR), when they may be in weather conditions that do not allow the pilots to see other aircraft. However, in very high-traffic areas, especially near major airports, aircraft flying under visual flight rules (VFR) are also required to follow instructions from ATC.

In addition to separation from other aircraft,  ATC may provide weather advisories, terrain separation, navigation assistance, and other services to pilots,  depending on their workload.

ATC do not control all flights. The majority of VFR flights in North America are not required to contact ATC (unless they are passing through a busy terminal area or using a major airport), and in many areas, such as northern Canada and low altitude in northern Scotland, Air traffic control services are not available even for IFR flights at lower altitudes.