Wing flap mechanism

Abstract

A carrier unit for chordwise extending and rotatably positioning an auxiliary airfoil mounted adjacent to the trailing edge of a relatively fixed main airfoil of an airplane. When the auxiliary airfoil is in a fully retracted and stowed position, the actuation and positioning linkage mechanism of the carrier unit is completely housed within the combined auxiliary and main airfoil envelope with no external protrusions or fairings. For auxiliary airfoil extension, to increase the overall chord plane by approximately eight percent, a first set of four-bar linkages is utilized comprising: a beam member supported at a forward portion by a pair of approximately parallel links pivoted to wing structure and swingable chordwise in a generally parallel relationship for translatably shifting the auxiliary airfoil which is pivoted to a rearward portion of the beam member. For changing the auxiliary airfoil angle-of-incidence relative to the main airfoil, one or more sets of four-bar linkages are integrated with the first set for a unified rotation programming and extension drive that functions to produce an aerodynamic slot opening when the auxiliary airfoil is extended to takeoff and landing positions whereat it is deflected up to approximately forty degrees relative to the main airfoil reference chord plane. For an aerodynamic braking action during landing roll-out, the geometrical relationship of the sets of four-bar linkages functions to deflect the auxiliary airfoil chord plane greater than forty degrees, to approximately ninety degrees or more relative to the main airfoil reference chord plane.