 Increased fuel prices in the mid-1970s to early 1980s, the SP's heavy wings, high cost, and 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 .