747SP- History and Development of the Rare and unique variant of the popular 747 family Part-1

The Boeing 747 is one of the most popular and recognizable planes in Aviation history and indeed it helped revolutionized air travel in one way or another. But, there is one variant that is still unknown to many people, the short and stubby 747SP. The 747SP has been developed from the original 747-100 model however it is completely different from other 747 variants. The 747SP was shorter compared to the regular 747 by nearly 48 feet and it also had other significant changes. The SP had the single slotted flaps instead of the triple slotted flaps of the 747 and the underwing canoes featured in other varients were completely eliminated. This helped the SP to be significantly lighter compared to other variants. The vertical stabilizer was taller on the SP which allowed for improved performance.

The 747SP was developed in response to the development of tri-jets in the form of the

DC-10 and the L-1011 and Pan Am, its launch customers, request to fly long haul and long and thin routes. Initially, the plane was supposed to be a trijet and also would have the same engine layout as the l-1011. This was done by Boeing in order to match the fuel economy of the rival trijets as this move would reduce fuel consumption. However, Boeing chief engineer Joe Stutter said that it was an engineering challenge to design the unique trijet configuration so the plane ended being 4 engined like the regular 747.

The weight-cutting measures ensured the improved performance of the jet.

The 747SP at its rollout ceremony in 1975

Credit- The Jet Age: The Life and Times of the Boeing 747SP (g-alyp.blogspot.com)

Initially named SB for short body but when the plane was launched, it was renamed SP for special performance. The aircraft was launched in 1973 and Pan Am, its launch customer, placed an order for 10 aircraft with 15 options. The first 747SP MSN- 21022 N747SP was revealed and flow its first flight in 1975. A year later the aircraft, N533PA "Clipper Freedom" was delivered to Pan Am.