► Boeing 747SP ( 'SP' for Special Performance) is a shortened version of the Boeing B747 widebody airliner, designed for a longer range.
► Originally named as 747SB for "short body", it later was nicknamed "Sutter's balloon" by employees after 747 chief engineer Joe Sutter.
Boeing later changed the production designation to 747SP for "special performance", reflecting the aircraft's greater range and higher cruising speed.
► Boeing needed a smaller aircraft to compete with the McDonnell Douglas DC-10 and L-1011 trijet wide bodies, introduced in year 1971/1972.
► Pan American World Airways requested a B747-100 derivative to fly between New York & Tehran,later Iran Air joined , & the first order came from Pan Am in 1973.
► The variant which first flew on 4th July 1975 , was approved by the FAA on February 4th, 1976, & entered into service that year with Pan Am.
► The Boeing 747SP is 47 ft (14 m) shorter than other 747 variants. Its main deck doors are reduced to four on each side to compensate for its lower capacity.
► The vertical & horizontal tailplane of the SP are larger & its wing flaps have been simplified.
► The vertical tail is taller to counteract the decrease in yaw moment-arm from the shortened fuselage.
► The 747SP uses single-piece flaps on the wing trailing edges, rather than the smaller triple-slotted flaps of standard 747s.
► With a 700,000 lb (320 t) MTOW, it can fly 276 passengers in three classes over 5,830 nmi (10,800 km).
► One of the 747SP was modified into the Stratospheric Observatory for Infrared Astronomy (SOFIA), used by NASA .
► Only 45 'stubby jumbo' aircrafts were ultimately produced because of low demands against 200 forecasted.
► As of Today , there are six Boeing 747SPs still in active service with 18 more stored and one preserved . The remaining 19 were scrapped.
By Gilbert Hechema - http://www.airliners.net/photo/Pratt-&
► Two of the Boeing 747SPs are being used by Pratt & Whitney as engine test beds.
