They are very valuable aerodynamic features as they significantly improve the efficiency of the wing design to improve fuel burn and handling characteristics on the latest and greatest jetliners. So if the most successful and best-engineered airliners have winglets, then the question becomes, why is there nothing similar found on the largest military transport aircraft in the world? At the time when the very biggest military transports were made, winglets were not yet proven enough technology to implement. The extreme wingspan of the world's largest military airlifters provides all the lift that these enormous jets need. This aircraft would completely change wing design, instead maximizing lift by using the airplane's fuselage as a primary surface.