How different is the Boeing 747SP from other Jumbo Jets?

The 747SP was the longest-range airliner available until it was superseded by the 747-400. The legendary Queen of the Skies, the Boeing 747 “Jumbo Jet”, is well-known and well-loved across the globe. With its iconic hump and large fuselage, the aircraft type continues to turn heads decades after its introduction. Since 1968, dozens of commercial and military variants of the 747 have been built. One of these is the Boeing 747SP (Special Performance).

Shorter fuselage, longer range
In the early 1970s, the McDonnell Douglas DC-10 and Lockheed L-1011 TriStar were introduced. In response, Boeing sought to develop a mid-sized widebody aircraft to compete with these new market entrants, having launched its massive 747 just shortly before.

Around the same time, the 747’s launch customer, Pan American World Airways (Pan Am), requested for a derivative to operate its longest route between New York and the Iranian capital of Tehran. Flag carrier Iran Air joined in on the request, looking for a jetliner that could travel the distance but was not as large as the standard 747.

Thus, in 1973, Boeing launched the 747SP: a variant of the 747-100 that was 47 feet (14 meters) shorter than the original. The variant was originally named 747SB (Short Body), but the suffix was later changed to SP to indicate its Special Performance features, namely its greater range and higher cruising speed.

Banking on its capabilities, a circumnavigation record was achieved by a United Airlines 747SP in 1988, with Neil Armstrong and Moya Marie Olsen Lear on board. The aircraft type was also involved in several other significant round-the-world attempts. The 747SP was the longest-range airliner at the time until it was superseded by the 747-400 in 1989.

Other differences
Apart from its shortened length – to optimize range and speed efficiencies – there were several differences adapted to the design of the 747SP. Rather than six cabin doors on each side, there are only four. Its flaps were also simplified to single pieces on the trailing edges instead of the triple-slotted flaps of standard 747s. To counteract the decrease in yaw moment-arm due to the shortened fuselage, the 747SP’s tailplane is larger vertically and horizontally.

The 747SP can carry 276 passengers in a three-class configuration, has a Maximum Take-Off Weight (MTOW) of 700,000 pounds (320,000 kg), and a range of over 5,830 nautical miles (10,800 km). In comparison, a standard 747 has a capacity of 366 passengers in three classes, a 745,000-pound (333,000-kg) MTOW, and a maximum range of 4,620 nautical miles (8,560 km).

Popularity
Despite its technical offerings, Boeing did not meet its expected sale of 200 units of 747SPs. This was, in part, due to rising fuel costs. Over the five decades that the 747 was in production, 1,574 have been made – but of these, only 45 are 747SPs. Other commercial variants, like the 747-200 and 747-400, fared much better, with 393 and 694 deliveries, respectively.

In 2012, after 40 years in service, Iran Air withdrew the last 747SP from commercial service. As of September 2022, only three units remain in use for non-commercial purposes. simpleflying.com