Abstract: Aircraft nacelles having adjustable chines are described. An example apparatus includes a chine coupled to a nacelle. The chine is oriented along a fore-aft direction. The chine is rotatable relative to the nacelle about an axis of rotation. The axis of rotation is substantially perpendicular to a plane of the chine defined by an outer mold line of the chine.

Abstract: A chine spoiler system enhances aircraft wing stall recovery characteristics while optimizing a maximum lift coefficient (CLMAX) of an aft-swept wing on an aircraft having an engine nacelle mounted below the wing. The system includes a chine located on a surface of the nacelle; the chine is configured to generate a vortex at high angles of attack. The vortex passes over an upper surface of the wing, favorably influencing inboard wing aerodynamics to delay airflow separation from the wing, in advance of a stall. The vortex increases CLMAX, but also creates a nose-up pitching moment on an aft-swept wing, which degrades stall recovery. A chine spoiler system module is configured to render the chine ineffective at predetermined wing flap configurations and angles of attack (typically post CLMAX) to balance the objectives of achieving high pre-stall CLMAX, while providing a nose-down pitching moment increment for improved stall recovery.

Abstract: Aircraft nacelles having adjustable chines are described. An example apparatus includes a chine coupled to a nacelle. The chine is oriented along a fore-aft direction. The chine is rotatable relative to the nacelle about an axis of rotation. The axis of rotation is substantially perpendicular to a plane of the chine defined by an outer mold line of the chine.

Abstract: A chine spoiler system enhances aircraft wing stall recovery characteristics while optimizing a maximum lift coefficient (CLMAX) of an aft-swept wing on an aircraft having an engine nacelle mounted below the wing. The system includes a chine located on a surface of the nacelle; the chine is configured to generate a vortex at high angles of attack. The vortex passes over an upper surface of the wing, favorably influencing inboard wing aerodynamics to delay airflow separation from the wing, in advance of a stall. The vortex increases CLMAX, but also creates a nose-up pitching moment on an aft-swept wing, which degrades stall recovery. A chine spoiler system module is configured to render the chine ineffective at predetermined wing flap configurations and angles of attack (typically post CLMAX) to balance the objectives of achieving high pre-stall CLMAX, while providing a nose-down pitching moment increment for improved stall recovery.

Abstract: Multi-positional tail skid assemblies and methods for their use. In one embodiment, a multi-positional tail skid assembly includes a skid member and a skid deployment system operably connected to the skid member. The skid member can include a first portion attachable to an aft portion of a fuselage and a second portion movable relative to the aft portion of the fuselage. The second portion can support a skid surface configured to contact a surface of a runway. The skid deployment system can be configured to move the skid surface between first and second positions. When the skid surface is in the first position, the skid surface is closer to the aft portion of the fuselage than when the skid surface is in the second position.

Abstract: Multi-positional tail skid assemblies and methods for their use. In one embodiment, a multi-positional tail skid assembly includes a skid member and a skid deployment system operably connected to the skid member. The skid member can include a first portion attachable to an aft portion of a fuselage and a second portion movable relative to the aft portion of the fuselage. The second portion can support a skid surface configured to contact a surface of a runway. The skid deployment system can be configured to move the skid surface between first and second positions. When the skid surface is in the first position, the skid surface is closer to the aft portion of the fuselage than when the skid surface is in the second position.

Abstract: An airplane having a fuselage (11), opposed main wings (12), and blunt-leading-edge raked wingtips (8) is provided. Each main wing includes an outboard end (9) and a leading edge (14) having an outboard end leading-edge nose and nose radius. One blunt raked wingtip (8) is located at each main wing outboard end (9) and includes a leading edge (20) swept back from the main wing leading edge (14). Each blunt raked wingtip (8) further includes a plurality of local airfoils each having a leading-edge nose radius and a chord. The nose radius is greater than about 2% of the local chord for the majority of the airfoils. The relative bluntness of the raked wingtips minimizes boundary-layer separation, drag associated with boundary-layer separation, and premature buffeting of the aircraft during low speed flight.