SPLIT WINGLET

A winglet system for an aircraft wing includes an upper winglet and a lower winglet mounted to a wing. The lower winglet has a static position when the wing is subject to an on-ground static loading. The lower winglet is configured such that upward deflection of the wing under an approximate 1-g flight loading causes the lower winglet to move upwardly and outwardly from the static position to an in-flight position resulting in an effective span increase of the wing under the approximate 1-g flight loading relative to the span of the wing under the on-ground static loading. The lower winglet is configured to aeroelastically deflect upwardly under the approximate 1-g flight loading and further increase the effective span of the wing beyond the effective span increase that is caused by the upward deflection of the wing.