Boeing 747SP

The Boeing 747SP (for Special Performance) is a shortened version of the Boeing 747 wide-body airliner, designed for a longer range. It is the highest flying subsonic passenger airliner, with a service ceiling of 45,100 feet (13,700 m). Boeing needed a smaller aircraft to compete with the McDonnell Douglas DC-10 and Lockheed L-1011 TriStar tri-jet wide-bodies, introduced in 1971/1972. Pan Am requested a 747-100 derivative to fly between New York and the Middle East, a request also shared by Iran Air, and the first order came from Pan Am in 1973. The variant first flew on July 4, 1975, was approved by the Federal Aviation Administration on February 4, 1976, and entered service that year with Pan Am. The SP is 184 feet 9 inches (56.31 m) in length, 47 feet (14 m) shorter than the original 747 variants. Its main deck doors are reduced to four on each side to suit its lower capacity. The vertical and horizontal tailplanes are larger and its wing flaps have been simplified. With a 700,000-pound (320 t; 320,000 kg) maximum take-off weight, it can fly 276 passengers in three classes over 5,830 nautical miles [nmi] (10,800 km; 6,710 mi). One 747SP was modified into the Stratospheric Observatory for Infrared Astronomy (SOFIA). The last example was delivered in 1987; some were converted to transports of heads of state. Sales did not meet the expected 200 units, and only 45 aircraft were ultimately produced.

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