What did the “SP” in Boeing 747SP stand for?

The “SP” in Boeing 747SP stood for “Special Performance.”

Boeing developed the 747SP as a shorter, lighter version of the 747-100. Its reduced fuselage length lowered weight and drag, allowing greater range and higher speed than earlier 747 models. The aircraft was intended especially for long, nonstop routes that were difficult for standard 747 variants.

The first 747SP flew in 1974, and Pan American World Airways introduced it commercially in 1976. Only 45 were built, making it one of the rarest production 747 variants. The abbreviation is sometimes incorrectly expanded as “Short Passenger,” because the aircraft had a shortened fuselage, but Boeing’s official meaning was “Special Performance.”

The 747SP also became notable for special missions, including astronomical observatories, research aircraft, and diplomatic transport. Its unusual proportions make it visually distinct from the longer 747-100 and 747-200.