Abstract: A ducted fan for a helicopter includes a transverse duct and a counter-torque device supported within the duct. The counter-torque device includes a rotor rotatably mounted within the duct and a stator fixedly mounted within the duct downstream from the rotor. The rotor includes a rotor hub having a rotor axis, and rotor blades extending from the hub. The Rotor blades have a modulated angular distribution about the rotor axis. The stator includes a stator hub, and a plurality of stator vanes distributed around the stator hub. The stator vanes are angularly modulated around the stator hub.

Abstract: A ducted fan for a helicopter includes a transverse duct and a counter-torque device supported within the duct. The counter-torque device includes a rotor rotatably mounted within the duct and a stator fixedly mounted within the duct downstream from the rotor. The rotor includes a rotor hub having a rotor axis, and rotor blades extending from the hub. The Rotor blades have a modulated angular distribution about the rotor axis. The stator includes a stator hub, and a plurality of stator vanes distributed around the stator hub. The stator vanes are angularly modulated around the stator hub.

Abstract: A ducted fan for a helicopter includes a transverse duct and a counter-torque device supported within the duct. The counter-torque device includes a rotor rotatably mounted within the duct and a stator fixedly mounted within the duct downstream from the rotor. The rotor includes a rotor hub having a rotor axis, and rotor blades extending from the hub. The Rotor blades have a modulated angular distribution about the rotor axis. The stator includes a stator hub, and a plurality of stator vanes distributed around the stator hub. The stator vanes are angularly modulated around the stator hub.

Abstract: A proprotor blade (27a, 27b, 127a, 127b) having a fixed, spanwise, leading edge slot (215) located in at least the inboard portion of the proprotor is disclosed. The slot (215) is formed by a selectively shaped slat (217) disposed in a selectively shaped recessed area (219) located at the leading edge (202) of the main portion of the proprotor blade. The slot (215) is selectively shaped so the a portion of the airflow over the lower airfoil surface of the proprotor blade is diverted between the main portion of the proprotor blade and the slat (217) and exits at the upper airfoil surface of the proprotor blade. The present invention may be used on both military-type tiltrotor aircraft (11) and civilian-type tiltrotor aircraft (111) with only minor variations to accommodate the different shapes of the proprotor blades.

Abstract: A ducted fan for a helicopter includes a transverse duct and a counter-torque device supported within the duct. The counter-torque device includes a rotor rotatably mounted within the duct and a stator fixedly mounted within the duct downstream from the rotor. The rotor includes a rotor hub having a rotor axis, and rotor blades extending from the hub. The Rotor blades have a modulated angular distribution about the rotor axis. The stator includes a stator hub, and a plurality of stator vanes distributed around the stator hub. The stator vanes are angularly modulated around the stator hub.

Abstract: The present invention provides an aircraft wing (10) having a main portion (20) with a trailing edge (20b) and a movable flaperon (22) hingedly secured at the trailing edge. A movable flaperon seal (40) is hingedly attached at its leading edge to the trailing edge of the main portion of the wing. Interconnecting structure is provided between the main portion of the wing and the flaperon seal. Such structure is operable to pivot the seal flap such that the opening between the trailing edge of the main wing portion (20b) and the leading edge of said movable flap (22a) on the upper surface is selectively closed by the movable flap at predetermined angular positions of the movable flap.