The 747-400 incorporates major aerodynamic improvements over earlier 747 models, including the addition of winglets to reduce drag, new avionics, a new flight deck and the latest in-flight entertainment systems. And, the 747 continues to be the world's fastest subsonic jetliner, cruising at Mach .855 -- or 85.5 percent of the speed of sound. The 747-400 has a range of approximately 7,260 nautical miles (13,450 km), and the lowest cost per seat-mile of any twin-aisle airplane in service today.