Background Information.

The concept for the Boeing 747SP came from a request by Pan Am for a 747 variant capable of carrying a full payload non-stop on its longest route between New York and Tehran. Iran Air also supported Pan Am's request,  their joint interest was for a high capacity airliner capable of covering Pan Am's New York - Middle Eastern routes and Iran Air's planned New York-Tehran route. The New York – Tehran was the longest non-stop commercial flight in the world at that point in time. The aircraft was launched in 1973 with Pan Am's first order. The first example was delivered in 1976.

This shorter derivative of the Boeing 747-100, known as the Boeing 747SP was developed by Boeing to target two market requirements. The first was a need to compete with the Douglas DC-10 and the Lockheed 1011 Tristar while maintaining commonality with the Boeing 747 which in its standard form was too large for many routes. Until the arrival of the Boeing 767, Boeing lacked a mid-sized wide-body to compete in this segment.

The second market requirement was for an aircraft suitable for the ultra-long-range routes emerging in the mid-1970s following the joint request. These routes needed not only longer range, but also a higher cruising speed. Boeing could not afford to develop an all-new design, instead it opted to shorten the 747 and optimize it for speed and range, at the expense of capacity.

The Boeing 747SP was originally designated the ‘747SB’ for ‘short body’. However it was later nicknamed ‘Sutter's balloon’ by Boeing employees after the 747s 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.

Production of the 747SP ran from 1976 to 1983. However a VIP order for the Royal Flight of Abu Dhabi led Boeing to produce one last SP in 1987. Pan Am was the launch customer for the 747SP, taking the delivery of their first aircraft ‘Clipper Freedom’ on March 05, 1976.

The 747SP was the longest-range airliner available until the Boeing 747-400 series 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, high acquisition cost, its reduced passenger 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 Boeing 747-300 and the 747-400 variant. 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 models. This same design was used in the 747-300 and resulted in a stretched upper deck.

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 on the standard 747s.

The 747SP could accommodate 230 passengers in a 3-class cabin or 331 in a (303 economy, 28 business) 2-class cabin. It is believed that a maximum of 400 passengers could be accommodated in an all-economy class layout, but this needs confirmation.

Forty-five 747SP aircraft were built between 1974 and 1987 with two more planned but not constructed. The production line was ended in 1982 but reopened in 1987 to fulfill an order for the United Arab Emirates.

As of June 2020, there were 7 Boeing 747SPs still in active service with 18 more stored and 1 preserved. The remaining 19 have either scrapped, otherwise destroyed or abandoned. In 2016, the last 747SP in commercial service was withdrawn from service after 40 years by Iran Air. The majority of the seven aircraft still in service are used for governmental or VIP transport.