Thursday, July 31, 2008

Concorde ... outrunning the spin of the earth.





First flown in 1969, Concorde service commenced in 1976 and continued for 27 years. It flew regular transatlantic flights from London Heathrow (British Airways) and Paris Charles de Gaulle (Air France) to New York JFK and Washington Dulles, flying these routes at record speeds, in under half the time of other airliners. Concorde also set many other records, including the official FAI "Westbound Around The World" and "Eastbound Around the World" world air speed records.
As a result of the type's only crash on 25 July 2000, world economic effects arising from the 9/11 attacks, and other factors, operations ceased on 24 October 2003. The last "retirement" flight occurred on 26 November that year.
Concorde remains an icon of aviation history, and has acquired an unusual nomenclature for an aircraft. In common usage in the United Kingdom, the type is known as "Concorde" rather than "the Concorde" or "a Concorde".
The experience of passing through the sound barrier was accompanied by a slight surge in acceleration, and was announced by one of the pilots.
At twice a conventional airliner's cruising altitude, the view from the windows clearly showed the curvature of the Earth, and turbulence was rare. During the supersonic cruise, although the outside air temperature was typically -60 °C (-75 °F), air compression would heat the external skin at the front of the aircraft to approximately +120 °C (250 °F), making the windows warm to the touch and producing a noticeable temperature gradient along the length of the cabin.
Concorde flew fast enough that the weight of everyone onboard was temporarily reduced by about 1% when flying east. This was due to centrifugal effects since the airspeed added to the rotation speed of the Earth. Flying west, the weight increased by about 0.3%, because it cancelled out the normal rotation and, with it, the normal centrifugal force and replaced it with a smaller rotation in the opposite direction. Concorde flew high enough that the weight of everyone onboard was reduced by an additional 0.6% due to the increased distance from the centre of the Earth.
Concorde's cruising speed exceeded the top speed of the solar terminator. Concorde was able to overtake or outrun the spin of the earth. On westbound flights it was possible to arrive at a local time earlier than the flight's departure time. On certain early evening transatlantic flights departing from Heathrow or Paris, it was possible to take off just after sunset and catch up with the sun, landing in daylight. This was much publicised by British Airways, who used the slogan "Arrive before you leave." The only one chance to see the sun rising up from West.

Thanks to Wiki...