Boeing 747SP UnitedBoeing 747SP United Airlines airplane model. Boeing developed the 747SP in the mid 1970s as a longer range, shortened 747, trading passenger seating for extra range. The 747SP is the only 747 model to feature a changed fuselage length compared with the 747 100. The 747SP first flew on July 4 1975, certification was awarded on February 4 1976 and first delivery (to Pan American) was in March 1976. The 747SP's fuselage is shortened by 14. 35m (47ft 1in)