Improved Aerodynamic Performance
The 747-400's most noticeable aerodynamic improvement is the 6-foot (1.8 m) longer wing with a 6-foot-high winglet angled upward and slightly outward. This change reduces fuel burn and extends the airplane's range.
The winglet provides the effect of having an even greater wingspan without outgrowing the standard airport slot.
The wingtip extension and winglet offer a fuel mileage improvement of about 3 percent.
The durable and lightweight winglets are made of graphite-epoxy materials, currently used on the all modern Boeing airplanes.
The composite and aluminum winglet saves 60 pounds (27 kg) per airplane compared to an all-aluminum structure.