วันเสาร์ที่ 10 พฤศจิกายน พ.ศ. 2550

1945 - 1991: The Cold War

Commercial Aviation took hold after World War II using mostly ex-military aircraft in the business of transporting people and goods. Within a few years many companies existed, with routes that criss-crossed North America, Europe and other parts of the world. This was accelerated due to the glut of heavy and super-heavy bomber airframes like the B-29 and Lancaster that could easily be converted into commercial aircraft. The DC-3 also made for easier and longer commercial flights. The first North American commercial jet airliner to fly was the Avro C102 Jetliner in September 1949, shortly after the British Comet. By 1952, the British state airline BOAC had introduced the De Havilland Comet into scheduled service. While a technical achievement, the plane suffered a series of highly public failures, as the shape of the windows led to cracks due to metal fatigue. The fatigue was caused by cycles of pressurization and depressurization of the cabin, and eventually led to catastrophic failure of the plane's fuselage. By the time the problems were overcome, other jet airliner designs had already taken to the skies. USSR's Aeroflot became the first airline in the world to operate sustained regular jet services on 15 September 1956 with the Tupolev Tu-104. Boeing 707, which established new levels of comfort, safety and passenger expectations, ushered in the age of mass commercial air travel as we enjoy it today.

Even with the end of World War II, there was still a need for advancement in aircraft and rocket technology. Not long after the war ended, in October of 1947, Chuck Yeager took the rocket powered Bell X-1 past the speed of sound. Although anecdotal evidence exists that some fighter pilots may have done so while divebombing ground targets during the war, this is the first controlled, level flight to cross the sound barrier. Further barriers of distance were eliminated in 1948 and 1952 as the first jet crossing of the Atlantic occurred and the first nonstop flight to Australia occurred.

During the 1950s, a new age of military aviation history would be written. When the Soviet Union developed long-range bombers that could deliver nuclear weapons to North America and Europe, Western countries responded with interceptor aircraft that could engage and destroy the bombers before they reached their destination. The "minister-of-everything" C.D. Howe in the Canadian government, was the key proponent of the Avro Arrow, designed as a high-speed interceptor, reputedly the fastest aircraft in its time. However, by 1955, most Western countries agreed that the interceptor age was replaced by guided missile age. Consequently, the Avro Arrow project was eventually cancelled in 1959 under Prime Minister John Diefenbaker. See Avro Arrow for more details.

In 1961, the sky was no longer the limit for manned flight, as Yuri Gagarin orbited once around the planet within 108 minutes. This action further heated up the space race that had started in 1957 with the launch of Sputnik 1 by the Soviet Union. The United States responded by launching Alan Shepard into space on a suborbital flight in a Mercury space capsule. With the launch of the Alouette I in 1963, Canada became the third country to send a satellite in space. The Space race between the United States and the Soviet Union would ultimately lead to the current pinnacle of human flight, the landing of men on the moon in 1969.

This historic achievement in space was not the only progress made in aviation at this time however. In 1967, the X-15 set the air speed record for an aircraft at 4,534 mph or Mach 6.1 (7,297 km/h). Aside from vehicles designed to fly in outer space, this record still stands as the air speed record for powered flight.

The same year that Neil Armstrong and Buzz Aldrin set foot on the moon, 1969, Boeing came out with its vision for the future of air travel, unveiling the Boeing 747 for the first time. This plane is still one of the largest aircraft ever to fly, and it carries millions of passengers each year. Commercial aviation progressed even further in 1975, as Soviet Aeroflot started regular service on Tu-144 — the first supersonic passenger plane, and in 1976, as British Airways inaugurated supersonic service across the Atlantic, courtesy of the Concorde. A few years earlier the SR-71 Blackbird had set the record for crossing the Atlantic in under 2 hours, and Concorde followed in its footsteps with passengers in tow.

The last quarter of the 20th century saw a slowing of the pace of advancement seen in the first three quarters of the century. No longer was revolutionary progress made in flight speeds, distances and technology. This part of the century saw the steady improvement of flight avionics, and a few minor milestones in flight progress.

For example, in 1979 the Gossamer Albatross became the first human powered aircraft to cross the English channel. This achievement finally saw the realization of centuries of dreams of human flight, but this has not had any significant impact on either commercial or military aviation. In 1986 Dick Rutan and Jeana Yeager flew an aircraft around the world unrefuelled, and without landing. In 1999 Bertrand Piccard became the first person to circle the earth in a balloon. By the end of the 20th Century there were no major or minor accomplishments left to be made in subsonic aviation. Focus was turning to the ultimate conquest of space and flight at faster than the speed of sound. The ANSARI X PRIZE inspired entrepreneurs and space enthusiasts to build their own rocket ships to fly faster than sound and climb into the lowest reaches of space.

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