Military Aviation in the Modern World

Kategorie: Dejepis (celkem: 1094 referátů a seminárek)

Informace o referátu:

  • Přidal/a: anonymous
  • Datum přidání: 06. února 2007
  • Zobrazeno: 2227×

Příbuzná témata



Military Aviation in the Modern World

Military Aviation in the Modern World

The United States and the Union of Soviet Socialist Republics (USSR) emerged as rival superpowers after 1945. American post-war strategy required a fleet of bombers capable of delivering nuclear weapons anywhere in the world. The B-29 and B-50 bombers were replaced by Consolidated's ten-engine (six-piston, four-jet) B-36 Peacemaker. The Boeing B-47, which used a revolutionary swept-wing design, was the first successful US strategic jet bomber. The Boeing B-52 Stratofortress became one of the most remarkable military aeroplanes of all time. First flown in 1952, it remained in service more than 40 years later. After the detonation of Britain's first nuclear weapon in 1952, the RAF, too, needed intercontinental bombers. It got them in the swept-back shape of the V-bombers: the Victor, Valiant, and Vulcan. The bat-like delta wing of the Vulcan gave it the most distinctive shape, and it was the most successful aircraft, remaining in front-line service as a bomber for 37 years.

The jet revolution also produced some remarkable fighter and attack aircraft. The RAF in the 1950s flew ageing Meteors, and newer Supermarine Swifts, Gloster Javelins, and the Hawker Hunters. The Hunter's elegant curves are still to be seen on air force bases in South America and the Far East. In Korea, the North American F-86 Sabre was involved in dogfights with the ugly but effective Soviet-built MiG-15.

A new generation of supersonic fighter aircraft appeared after 1953. The North American F-100 Super Sabre; the Convair F-102 Delta Dagger; the English Electric Lightning; and the USSR's twin-engine MiG-19 were typical of the era. Russian-built MiGs in their hundreds were supplied to other Communist states. Their neighbours sought out Western aircraft to defend themselves. Few military aircraft of the 1960s were as commercially successful as the French-built Dassault-Mirage III, which has served with 15 of the world's air forces.

VTOL

In the 1960s there was the appearance of two more advanced aircraft technologies, but neither had the impact that might have been expected. The Hawker Harrier was the world's first vertical take-off and landing (VTOL) jet fighter. Its powerful Rolls-Royce Pegasus engine blasts air through four swivelling nozzles: pointed downward for take-off, they rotate backward as the aircraft accelerates into wing-borne flight.

In fact, Harriers rarely take off vertically, since they can carry a much greater weapons load if they roll forward in a short take-off run. But the aircraft can be operated from short sections of road away from an airfield or from damaged runways. Despite the Harrier's success with the RAF and US Marine Corps, no other vertical take-off jet has been developed in the West, and Russia's attempt, a naval fighter, was an operational failure.

Swing-Wing Aircraft

Slightly more popular was the "swing-wing", an idea originally conceived by the inventor of the bouncing bombs of Britain's World War II raids on German dams, Barnes Wallis. Swept delta wings are ideal for high-speed supersonic flight, but they are less suited to low-level flight at slower speeds. Straight, high-lift wings are far better for take-off and landing. The swing-wing is an attempt to achieve the best of both worlds. The wing pivots round a "shoulder" near the wing root. For take-off, it extends straight out from the aircraft. When the pilot wants to increase speed, the wings sweep back to form a delta triangle. The first aircraft to be developed with swing-wings was the Convair F-111, designed for the US Navy, but in the event serving only with the US Air Force (USAF). The multinational Tornado, in both bomber and interceptor versions, is the only swing-wing aircraft in European service; the US Navy flies the F-14 Tomcat fighter from its carriers. Although the swing-wing does solve some problems, the added complexity and weight of the swinging mechanism have conspired to prevent it being used in many designs.

While America learned the lessons of the Vietnam War, the Soviet Union continued to build increasingly sophisticated aircraft. The swing-wing MiG-23 Flogger and Mach 3 MiG-25 Foxbat astounded Western observers when they first appeared in the 1970s. Soviet aircraft were built to operate from rapidly prepared forward bases and rough airstrips. They are robust, heavy, and unsophisticated to Western eyes. However, they are attractive to many air forces in developing countries because of that very robustness and ability to operate without the technologically advanced facilities that are vital to keep a Western jet fighter in the air. The Soviet Air Force is also equipped with a supersonic heavy bomber: the swing-wing Tupolev Tu-160 Blackjack.

Collaborative Projects

The sheer cost of developing a new military aircraft has forced European countries to work together.

The tri-national Tornado was a collaboration between Britain, Germany, and Italy, and its successor, the Eurofighter 2000, previously known as the European Fighter Aircraft, also includes Spain. The Eurofighter 2000 is a single-seat fighter equipped with fly-by-wire electronics, including a voice-controlled computer system, and the airframe makes extensive use of advanced carbon-fibre composite materials. The Future European Fighter Aircraft project was originally begun by British Aerospace in the early 1980s, with production aircraft scheduled to enter service in the mid-1990s. However, delays and conflicts over design and scheduling ensued, and following France's departure from the programme in 1985, the project was re-named Eurofighter 2000 by the remaining participating nations. The first of seven Eurofighter prototypes made its first flight in March 1994; aircraft are scheduled to enter service in 2001.

Dassault, builders of the Mirage, created the Rafale, an equally advanced aircraft. The Rafale will, at great expense, serve with the French Air Force and aboard the carriers of the French Navy. Sweden's SAAB, builders of such distinctive aircraft as the 1950s-vintage crank-winged Draken, and 1970s Viggen, a heavyweight fighter-bomber with large foreplanes mounted ahead of the delta wing, is building a lightweight fighter called the JAS-39 Gripen, which should cost about half the price of a Eurofighter or Rafale.

The lessons of Vietnam resulted in two new aircraft for the USAF: the General Dynamics F-16 and the McDonnell-Douglas F-15. The F-16 was originally an experimental lightweight fighter prototype, which was so successful that the USAF and other air forces bought it in large numbers. Single-engined, the F-16 was built for manoeuvrability. The F-15 Eagle is a much larger twin-engined fighter, originally designed in a single-seat version to combat the Soviet MiG-25 Foxbat. However, the latest model, the F-15E, is an advanced ground-attack aircraft for a two-man crew. Once again, cost encourages plane-makers to get the most out of a tried and tested airframe rather than design anew.

Aircraft such as Russia's MiG-29 and Sukhoi Su-27, Eurofighters, and F-16s were designed not just for the superpower air forces which were their first customers, but for the air forces of developing nations. The race for new technology at any cost, which drove military aircraft development from World War I to the 1980s, has now been moderated by a new awareness of the economics of air fleets.

Nový příspěvek



Ochrana proti spamu. Kolik je 2x4?