Abstract: In an aircraft exhibiting an undesirable nose-down pitching moment due to a rearward shift of the wing lift acting aft of the characteristic pitch axis of the aircraft as speed increases in a certain speed regime, the vertical member of the tail section is configured to develop an increasing drag. The increasing tail member drag acts in elevation above the horizontal plane that contains the pitch axis so as to develop a counteracting nose-up pitching moment that mitigates the unwanted nose-down pitching component associated with changing wing lift characteristics.

Abstract: A swept wing for jet transports having a thickness-chord length (t/c) ratio that continuously decreases (i.e., tapers) from the wing root to the wing tip is disclosed. The tapered t/c ratio wing has reduced weight and improved overall efficiency when compared to conventional, constant t/c ratio wings. While the t/c ratio of the wing tapers, the combined structural and skin strength of the wing remains adequate to handle bending loads imposed by lift and engine weight. In this regard, the cross-sectional thickness of the midspan region of the wing is chosen such that the wing skin thickness can be reduced to the minimum allowable for the skin material. Also, the cross-sectional thickness of the outboard region of the wing is decreased, resulting in decreased drag and weight in this region. Further, the camber of the outboard portion of the wing is increased (as compared to the camber of a constant t/c ratio wing) to prevent the unsweeping of spanwise oriented isobars.

Abstract: Disclosed is an airplane all-moving airfoil having a moment reducing apex for facilitating control of the airfoil. In a preferred embodiment, the apex protrudes forward from the leading edge of an all-moving horizontal stabilizer and operates through its aerodynamic effect on the stabilizer to reduce the moment required to maintain and vary the stabilizer position. Counter-rotating airflow vortices produced by the apex reduce the rearward displacement of the center of pressure on the stabilizer as the stabilizer is deflected into an increasing angle of attack. As a result, lighter weight hydraulic stabilizer and elevator actuating mechanisms can be employed. In a preferred embodiment an aeroelastically flexible apex is employed to enhance moment reduction at high angles of attack.