Boeing 747SP - Design

Design

Apart from having a significantly shorter fuselage and one fewer cabin door per side, the 747SP differs from other 747 variants in having simplified flaps and a taller vertical tail to counteract the decrease in yaw moment-arm from the shortened fuselage. The 747SP uses single-piece flaps on the trailing edges, rather than the smaller triple-slotted flaps of standard 747s. The SP was also the first— and until the introduction of the Boeing 777-200LR (and eventually the 787-8) the only—Boeing wide-body with a wingspan greater than the length of the fuselage.

The SP could accommodate 230 passengers in a 3-class cabin or 331 in a (303 economy, 28 business) 2-class cabin, and a maximum of 440 passengers in one class. Originally designated 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 longer range and faster cruise speed. Pan Am was the launch customer for the 747SP, taking the first delivery, Clipper Freedom, on March 5, 1976, followed by Iran Air.

The 747SP was the longest-range airliner available until the 747-400 entered service in 1989. Despite its technical achievements, the SP never sold as well as Boeing hoped. Increased fuel prices in the mid 1970s to early 1980s, the SP's heavy wings, expensive cost, reduced capacity, and the increased ranges of forthcoming airliners were some of the many factors that contributed to its low sales. Only 45 were built and of those remaining, most are used by operators in the Middle East. However, some of the engineering work on the 747SP was reused with the development of the 747-300 and 747-400. In the 747SP, the upper deck begins over the section of fuselage that contains the wingbox, not ahead of the wingbox as is the case with the 747-100 and 747-200. This same design was used in the 747-300 and 747-400 resulting in a stretched upper deck.