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The Boeing 747
can trace its roots back to a 1962 military requirement for the US Air
Force. Pan Am issued a letter of intent to purchase the new aircraft in
December 1965, with the conditions that it would be able to carry 400
passengers a distance of 8,064 km (5,000 miles). Over 50 different designs
were considered but in the end a wide-body, twin aisle layout was chosen
with the flight deck on an upper deck. Pan Am became the launch customer
in April 1966 by ordering 25 Boeing 747-100's (23 passenger and 2 freight
aircraft). The order, valued at $550 million was the largest ever placed
for commercial aircraft at that time. Everything about the new 747 was
big. The passenger cabin was almost twice the width of the 707's and the
aircraft was 24.07 m (79 ft) longer than the 707-300. However more impressingly,
the aircraft contained around six million parts, over 217.25 km (135
miles) of wiring and over a ton of air when pressurised. The first 747 was
rolled out at the Everett plant on September 30, 1968 with the
registration N7470. At that point of the 747 programme Boeing had already
received over 200 orders from 26 airlines worldwide. Throughout 1969
testing of the 747 continued and FAA certification was given on December
30, 1969 after 1,400 hours of flying time. The first scheduled flight by
Pan Am was due to take place on January 21, 1970 but a minor engine
problem necessitated a change of aircraft so departure was delayed until
the early hours of the 22nd. By the end of 1970 twelve airlines were
operating the 747-100: Pan Am, American, Continental, Delta, National,
Northwest Orient, United, Air France, Alitalia, Iberia, Lufthansa and
Japan Airlines. The final 747-100 was delivered on July 12, 1976.
Although the 747-200 was
developed after the 747-100, it was built during roughly the same timeframe.
Although the 747-200's external appearance looked identical to the 747-100,
it was designed to carry more payload. The 747-200 was also the first 747 to
be available in different versions: passenger only, a freighter, a
combination passenger-freighter and a convertible. Originally called the
747B, the 747-200 kept the same dimensions of the 747-100 but offered
greater range by allowing the carriage of additional fuel. Considerable
structural strengthening was undertaken in most areas of the airframe but in
particular in the wings and undercarriage. The product of all the
strengthening was a maximum take-off weight of 351,540kg (775,000lb).
However the maximum take-off weight was increased with the introduction of
more powerful engines from all three major manufacturers: P&W, General
Electric and Rolls-Royce. From the beginning, the 747 was designed to serve
as an all-cargo transport. The first 747 Freighter could easily carry 90,000
kg (100 tons) across the Atlantic Ocean or across the United States. Its
operating cost was 35 percent less per ton mile than the 707 Freighter. The
747 Freighter has a hinged nose to allow cargo loading through front of the
airplane, with the option of a large side-cargo door. The first 747-200 went
into commercial service in February 1971 with launch customer KLM.
Altogether Boeing delivered a total of 393 747-200's, the last in 1991.
In the 1970's Boeing's competitors decided to concentrate on shorter-haul aircraft to replace the 707 and DC-8. Lockheed entered this sector with the L-1011 Tristar and McDonnell Douglas introduced the DC-10. Boeing knew that it had to compete in the field and to save time it looked into shortening the 747 fuselage instead of developing a new aircraft. The results was the 747-SP (Special Performance) or more affectionately known as the 'Baby Jumbo'. The new aircraft was able to carry 281 passengers in a typical mixed class layout. Once again Pan Am was the launch customer and placed a $280 million order for ten aircraft, plus spares and fifteen options, in 1973. Building the 747-SP involved a fuselage reduction of 14.7 m (48 ft 4 in). However other structural changes were needed including an increase in the horizontal tail span and increasing the height of the tail fin. The first flight of a 747-SP (registered N747SP) occurred on July 4, 1975, in the hands of Jack Waddell. The aircraft was a complete success and managed to reach an incredible top speed of Mach 0.92. Pan Am put its first aircraft into Service from April 1976 and the type also saw service with Iranair and South African Airlines. However the predicted sales targets were never met, with only 44 -SP's ever being built.
The 747-300 was launched with an order for 5 aircraft from Swissair, two passenger versions and three combis. The 747-300 was basically a 747-200 with an extended upper deck. The aircraft's 'hump' was extended by 7.10 m (23 ft 4 in) permitting carriage of 44 additional passengers when compared to the -200. In total, 91 tourist class seats or 38 business class seats could be accommodated in the new upper deck.
The 747-300 was not ordered in substantial quantities by airlines and only 81 aircraft were produced (Many airlines were waiting for the new technologically advanced 747-400 to be launched). Boeing is currently undergoing a freighter conversion program for the 747-300 with Atlas Air being the first customer. Deliver of the first converted aircraft tool place in October 2000. Boeing anticipates that as many as 40 -300's could be converted to freighters during the next 20 years.
In the 1980's Boeing learned that airlines
wanted more than a revamped version of the original 747. With aircraft such as
the MD-11 and the airbus family being developed Boeing was under increasing
pressure to produce something special. In May 1985 Boeing announced that it was
to develop the 747-400 - an advanced evolution of the 747-300. The new aircraft
was to feature modern avionics, increased range and capacity, a new interior and
reduced fuel burn and operating costs. A new two-man cockpit was developed
featuring the very latest digital avionics. The 747-400
also features improved wings incorporating 1.8 m (6 ft) winglets which help to
reduce drag and offer 3% more range. The 747-400 can use any of three types of
engines from existing 747 suppliers; the Pratt & Whitney PW4056, the General
Electric CF680C2B1F or the Rolls Royce RB211-524G. The new interior of the
747-400 was designed to offer maximum flexibility. There are 157 possible
combinations for galleys and toilets can be located in 121 locations due to the
new vacuum waste system. Crew rest areas were also provided on the aircraft due
to the length of flights it can make. Northwest Airlines was the launch customer
for the 747-400 ordering their first aircraft in October 1985. First flight of
the aircraft took place in April 1988 and the first delivery to Northwest took
place in 1989. In the 747-400 family there is also the 747-400D capable of
carrying 586 economy passengers, currently the largest number able to be carried
in a commercial airliner.
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