GB712028A - Airplane flap control mechanism - Google Patents

Abstract

712,028. Controlling aircraft. BOEING AIRPLANE CO. Nov. 10, 1952, No. 28291/52. Class 4 A control mechanism for a wing flap on an aircraft in which the flaps may be operated conjointly with ailerons to improve lateral control at low landing speeds comprises tracks carried by the wing pivotally supporting the flap and guiding it for movement relative to the wing between retracted and projected positions and a further track having a curvature such that the incidence of the flap is varied with retracting and extending movements and means associated with the aileron control mechanism to move the curved track normally to the plane of the wing so that the incidence of the flap, in its extended positon, may be adjusted. The wing 12 carries cantilever tracks 24<SP>1</SP> having roller carriages for supporting arms 14<SP>1</SP> downwardly cranked at their ends and pivotally connected at 20' to the flap 10. Fore and aft movement of the flap is effected by screw and nut mechanisms 56, 58 operated by a drive shaft 55. To vary the incidence of the flap an arm 42 thereon carries a roller carriage 46 which cooperates with a curved track 44 on an arm 48, pivoted at 74 to the wing structure 34 and connected to an operating jack 76. The control for the jack may be associated with the aileron controls so that if, at low speeds an aileron is moved above its mid-position the flap on that side of the aircraft will automatically be raised, the position of the other flap remaining unaltered. In a further embodiment (Fig. 1, not shown) the downwardly cranked end of the arm 14' is replaced by a bellcrank arm, pivotally secured to the arm 14<SP>1</SP> and to the flap 10 and having- a forward extension which carries a roller carriage cooperating with a curved track on the arm 24<SP>1</SP> similar to the track 44.