A wingtip fence refers to the winglets including surfaces extending both above and below the wingtip, as described in Whitcomb's early research.[1] Both surfaces are shorter than or equivalent to a winglet possessing similar aerodynamic benefits. The Airbus A310-300 was the first airliner with wingtip fences in 1985.[21] Other Airbus models followed with the A300-600, the A320ceo, and the A380. Other Airbus models including the A320 Enhanced, A320neo, A350 and A330neo have blended winglets rather than wingtip fences.