Abstract: A rotorcraft may include an airframe and a rotor connected to the airframe. The rotor may include a plurality of blades defining ducts along the length thereof and vents in fluid communication with the ducts. Flow from through the vents may be controlled by valves with piezoelectric actuators. The valves may be adjusted to achieve a lift profile suited for an operational mode such as vertical, autorotative, or unloaded flight. The lift profile may vary along the length of the blade and may vary cyclically with rotation of the blade. The lift profile may be chosen to approximate a figure of merit for the rotor suitable for a given operational mode.

Abstract: A rotor system is disclosed for a reactive drive rotary wing aircraft. Apparatus and methods are disclosed for maintaining the rigidity of the rotor and eliminating play between flight controls and the rotor by mounting swashplate actuators to a flange rigidly secured to the mast. Apparatus and methods are disclosed for thermal management of the rotor in order to avoid bearing failure or loss of bearing preload. Methods include modulating the temperature of oil pumped over one or more of the mast bearing, swashplate bearing, and spindle bearing. The temperature of air passively or actively drawn through rotor may also be modulated to maintain bearing temperature within a predetermined range. Structures for reducing pressure losses and drag on components due to air flow through the rotor are also disclosed. A rotor facilitating thermal management by oil and air flow is also disclosed.

Abstract: The rotorcraft may include an airframe, at least one engine connected to the airframe, and a rotor connected to the airframe. The rotor may include a hub, a rotor blade, and a feathering spindle connected to the hub. The rotor blade may have a root and a tip and form a conduit extending in the radial direction from the root to the tip. The root may comprise a wall forming a hollow circular cylinder. The hollow circular cylinder may form a portion of the conduit. A plurality of bolts may be distributed circumferential within the wall of the root. The plurality of bolts may extend in the radial direction from the wall of the root to secure the rotor blade to the feathering spindle.

Abstract: A rotor system for a reactive drive rotary wing maintains the rigidity of the rotor and eliminates play between flight controls and the rotor by mounting swashplate actuators to a flange rigidly secured to the mast. Apparatus and methods perform thermal management of the rotor in order to avoid bearing failure or loss of bearing preload. Methods include modulating the temperature of oil pumped over one or more of the mast bearing, swashplate bearing, and spindle bearing. The temperature of air passively or actively drawn through rotor may also be modulated to maintain bearing temperature within a predetermined range. The rotor includes structures for reducing pressure losses and drag on components due to air flow through the rotor. A rotor facilitates thermal management by oil and air flow.

Abstract: A rotorcraft may include an airframe and a rotor connected to the airframe. The rotor may include a plurality of blades defining ducts along the length thereof and vents in fluid communication with the ducts. Flow from through the vents may be controlled by valves with piezoelectric actuators. The valves may be adjusted to achieve a lift profile suited for an operational mode such as vertical, autorotative, or unloaded flight. The lift profile may vary along the length of the blade and may vary cyclically with rotation of the blade. The lift profile may be chosen to approximate a figure of merit for the rotor suitable for a given operational mode.

Abstract: A rotor system is disclosed for a reactive drive rotary wing aircraft. Apparatus and methods are disclosed for mounting to the rotor hub certain controls, both electrical and mechanical, as well as fuel delivery for tipjets mounted to rotor blades. Air passively or actively drawn through rotor may feed the tipjets directly through the blades, while fuel and control is delivered along the blade to the tip thereof.

Abstract: A rotorcraft is disclosed. The rotorcraft may include an airframe, at least one engine connected to the airframe, and a rotor connected to the airframe. The rotor may include a hub, a rotor blade, and a feathering spindle connecting the rotor blade to the hub. The rotorcraft may further include a flow of oil passing proximate the feathering spindle. The flow of oil may cool the feathering spindle during take off and landing of the rotorcraft. Additionally, the flow of oil may heat the feathering spindle during travel of the rotorcraft at altitude.

Abstract: A rotor system is disclosed for a reactive drive rotary wing aircraft. Apparatus and methods are disclosed for maintaining the rigidity of the rotor and eliminating play between flight controls and the rotor by mounting swashplate actuators to a flange rigidly secured to the mast. Methods are disclosed for modulating the temperature of oil pumped over one or more of the mast bearing, swashplate bearing, and spindle bearing. The temperature of air passively or actively drawn through rotor may also be modulated to maintain bearing temperature within a predetermined range. Structures for reducing pressure losses and drag on components due to air flow through the rotor are also disclosed. A rotor facilitating thermal management by oil and air flow is also disclosed. Surfaces interfacing between the swashplate and the mast and between control rods and the swashplate or pitch horn may bear a solid lubricant layer.

Abstract: A rotor system of a reactive drive rotary wing maintains rigidity and stiffness and resists slack and backlash by mounting swashplate actuators to a flange rigidly secured to the mast, and may be monolithic therewith. A mast tilt actuator and a mast pivot may secure to the mast flange, with vibration suppressors. A shroud may provide a sealed fluid path for airflow therethrough encircling portions of the rotor hub and restricting airflow between the rotor hub and shroud. A rotor cavity, in fluid communication with blade ducts (hollow portions of the blade spars), and either or both contoured to reduce pressure losses, may assist in temperature control, and may feed into tip jets on the blades.

Abstract: A rotorcraft may include an airframe and a rotor connected to the airframe. The rotor may include a plurality of blades defining ducts along the length thereof and vents in fluid communication with the ducts. Flow from through the vents may be controlled by valves with piezoelectric actuators. The valves may be adjusted to achieve a lift profile suited for an operational mode such as vertical, autorotative, or unloaded flight. The lift profile may vary along the length of the blade and may vary cyclically with rotation of the blade. The lift profile may be chosen to approximate a figure of merit for the rotor suitable for a given operational mode.

Abstract: A rotor system is disclosed for a reactive drive rotary wing aircraft. Apparatus and methods are disclosed for maintaining the rigidity of the rotor and eliminating play between flight controls and the rotor by mounting swashplate actuators to a flange rigidly secured to the mast. Methods are disclosed for modulating the temperature of oil pumped over one or more of the mast bearing, swashplate bearing, and spindle bearing. The temperature of air passively or actively drawn through rotor may also be modulated to maintain bearing temperature within a predetermined range. Structures for reducing pressure losses and drag on components due to air flow through the rotor are also disclosed. A rotor facilitating thermal management by oil and air flow is also disclosed. Surfaces interfacing between the swashplate and the mast and between control rods and the swashplate or pitch horn may bear a solid lubricant layer.

Abstract: The rotorcraft may include an airframe, at least one engine connected to the airframe, and a rotor connected to the airframe. The rotor may include a hub, a rotor blade, and a feathering spindle connected to the hub. The rotor blade may have a root and a tip and form a conduit extending in the radial 5 direction from the root to the tip. The root may comprise a wall forming a hollow circular cylinder. The hollow circular cylinder may form a portion of the conduit. A plurality of bolts may be distributed circumferential within the wall of the root. The plurality of bolts may extend in the radial direction from the wall of the root to secure the rotor blade to the feathering 10 spindle.

Abstract: Apparatus and methods is used for controlling yaw of a rotorcraft in the event of one or both of low airspeed and engine failure. A yaw propulsion provides a yaw moment at low speeds. The yaw propulsion device may be an air jet or a fan. A pneumatic fan may be driven by compressed air released into a channel surrounding an outer portion of the fan. The fan may be driven by hydraulic power. Power for the yaw propulsion device and other system may be provided by a hydraulic pump and/or generator engaging the rotor. Low speed yaw control may be provided by auxiliary rudders positioned within the stream tube of a prop. The auxiliary rudders may one or both of fold down and disengage from rudder controls when not in use. A power take-off engages a rotor and is engaged in response to detecting a loss of engine power.

Abstract: A rotor system is disclosed for a reactive drive rotary wing aircraft. Apparatus and methods are disclosed for maintaining the rigidity of the rotor and eliminating play between flight controls and the rotor by mounting swashplate actuators to a flange rigidly secured to the mast. Apparatus and methods are disclosed for thermal management of the rotor in order to avoid bearing failure or loss of bearing preload. Methods include modulating the temperature of oil pumped over one or more of the mast bearing, swashplate bearing, and spindle bearing. The temperature of air passively or actively drawn through rotor may also be modulated to maintain bearing temperature within a predetermined range. Structures for reducing pressure losses and drag on components due to air flow through the rotor are also disclosed. A rotor facilitating thermal management by oil and air flow is also disclosed.

Abstract: An aircraft is disclosed having an engine and a propeller mounted to a fuselage. An empennage mounts to the aircraft and includes first and second horizontal stabilizers separated by a distance greater than the diameter of a stream tube of the propeller at the horizontal stabilizers. A rudder extends between the horizontal stabilizers and is positioned within the stream tube of the propeller. A bulkhead is positioned rearwardly from the cockpit and oriented perpendicular to a longitudinal axis of the airframe. A tailboom and engine are mounted to the airframe by means of the bulkhead having the engine mounted between the tailboom and a lower edge of the bulkhead. Landing gear may mount to the bulkhead proximate a lower edge thereof.

Abstract: A rotorcraft is disclosed. The rotorcraft may include an airframe and a rotor connected to the airframe. The rotor may include a hub and at least one rotor blade having a tip jet. The rotorcraft may further include a plurality of compressors for generating compressed air and a network of conduits connecting the outlets of the plurality of compressors with every tip jet of the rotor. The rotorcraft may further include a control system preventing back flow through each outlet of the plurality of compressors.

Abstract: A rotor system is disclosed for a reactive drive rotary wing aircraft. Rigidity of the rotor is enhanced and play between flight controls and the rotor are eliminated by mounting swashplate actuators to a flange rigidly secured to the mast. Thermal management of the rotor is performed in order to avoid bearing failure or loss of bearing preload. Methods include modulating the temperature of oil pumped over one or more of the mast bearing, swashplate bearing, and spindle bearing. The temperature of air passively or actively drawn through rotor may also be modulated to maintain bearing temperature within a predetermined range. Structures for reducing pressure losses and drag on components due to air flow through the rotor are also disclosed. Thermal management of a rotor may be performed by oil and air flow.

Abstract: A rotorcraft may include an airframe and a rotor connected to the airframe. The rotor may include a plurality of blades defining ducts along the length thereof and vents in fluid communication with the ducts. Flow from through the vents may be controlled by valves with piezoelectric actuators. The valves may be adjusted to achieve a lift profile suited for an operational mode such as vertical, autorotative, or unloaded flight. The lift profile may vary along the length of the blade and may vary cyclically with rotation of the blade. The lift profile may be chosen to approximate a figure of merit for the rotor suitable for a given operational mode.

Abstract: An aircraft is disclosed having an engine and a propeller mounted to a fuselage. An empennage mounts to the aircraft and includes first and second horizontal stabilizers separated by a distance greater than the diameter of a stream tube of the propeller at the horizontal stabilizers. A rudder extends between the horizontal stabilizers and is positioned within the stream tube of the propeller. A bulkhead is positioned rearwardly from the cockpit and oriented perpendicular to a longitudinal axis of the airframe. A tailboom and engine are mounted to the airframe by means of the bulkhead having the engine mounted between the tailboom and a lower edge of the bulkhead. Landing gear may mount to the bulkhead proximate a lower edge thereof.

Abstract: A rotorcraft is disclosed. The rotorcraft may include an airframe comprising a mast defining an interior cavity, at least one compressor connected to the airframe, and a rotor. The rotor may include a hub and a rotor blade. The hub may connect to the mast to rotate with respect thereto. The hub may also define an interior cavity. The rotor blade may form a radial conduit extending radially therewithin. A flow of compressed air generated by the at least one compressor may pass from the at least one compressor, through the interior cavity defined by the mast, through the interior cavity defined by the hub, and into the radial conduit. A swashplate assembly controlling pitch of the rotor blade may be located exterior to the hub and mast. Accordingly, the swashplate assembly may not be heated by the flow of compressed air.