Abstract: A system and method for slowing the rotation of a rotor using, for example, rotor brake system for a rotorcraft comprises: one or more generators connected to a main rotor gearbox; an electric distributed anti-torque system mounted on a tail boom of the rotorcraft comprising two or more electric motors connected to the one or more generators, wherein the two or more electric motors are connected to one or more blades; and wherein a rotation of the rotor is slowed by placing a drive load on the main rotor gearbox with the one or more generators to bleed the mechanical power from rotor into electrical power via the two or more electric motors, wherein the electric distributed anti-torque system generates thrust in opposing directions.

Abstract: A propulsion system for a rotorcraft includes a first fan assembly including a plurality of first fan blades, a second fan assembly including a plurality of second fan blades and a drive system adapted to provide torque to the first and second fan blades. The first fan blades have a larger rotational inertia than the second fan blades. The second fan blades are adapted to experience a larger angular acceleration than the first fan blades in response to torque from the drive system, thereby providing responsive thrust control for the rotorcraft.

Abstract: A modal restraint system for an occupant of a seat of an aircraft. The modal restraint system includes a strap feeder unit and a strap selectively retractable into and extendable from the strap feeder unit. The strap feeder unit is adapted to switch between a plurality of modes including an unfixed mode and a fixed mode. The strap is extendable from and retractable into the strap feeder unit in the unfixed mode. The strap is substantially unextendable from the strap feeder unit in the fixed mode. The strap feeder unit is in the unfixed mode by default. The strap feeder unit is operable to switch from the unfixed mode to the fixed mode in response to a precautionary event including detection of an operational parameter that is beyond a predetermined threshold, thereby reducing freedom of movement of the occupant relative to the seat.

Abstract: An anti-torque system for a rotorcraft includes a first tail fan assembly including a plurality of first fan blades and a second tail fan assembly including a plurality of second fan blades. The first tail fan assembly has a larger diameter than the second tail fan assembly. The first fan blades have a larger rotational inertia than the second fan blades such that the second fan blades experience a larger angular acceleration than the first fan blades in response to torque, thereby providing yaw control for the rotorcraft.

Abstract: A modal restraint system for an occupant of a seat of an aircraft. The modal restraint system includes a strap feeder unit and a strap selectively retractable into and extendable from the strap feeder unit. The strap feeder unit is adapted to switch between a plurality of modes including an unfixed mode and a fixed mode. The strap is extendable from and retractable into the strap feeder unit in the unfixed mode. The strap is substantially unextendable from the strap feeder unit in the fixed mode. The strap feeder unit is in the unfixed mode by default. The strap feeder unit is operable to switch from the unfixed mode to the fixed mode in response to a precautionary event including detection of an operational parameter that is beyond a predetermined threshold, thereby reducing freedom of movement of the occupant relative to the seat.

Abstract: A system and method for slowing the rotation of a rotor using, for example, rotor brake system for a rotorcraft comprises: one or more generators connected to a main rotor gearbox; an electric distributed anti-torque system mounted on a tail boom of the rotorcraft comprising two or more electric motors connected to the one or more generators, wherein the two or more electric motors are connected to one or more blades; and wherein a rotation of the rotor is slowed by placing a drive load on the main rotor gearbox with the one or more generators to bleed the mechanical power from rotor into electrical power via the two or more electric motors, wherein the electric distributed anti-torque system generates thrust in opposing directions.

Abstract: A modal restraint system for an occupant of a seat of an aircraft having a mechanical failure sensor includes a strap feeder unit and a strap selectively retractable into and extendable from the strap feeder unit. The strap is positionable adjacent to the occupant. The strap feeder unit is adapted to switch between a plurality of modes including an unfixed mode and a fixed mode. The strap is extendable from and retractable into the strap feeder unit in the unfixed mode. The strap is substantially unextendable from the strap feeder unit in the fixed mode. The strap feeder unit is in the unfixed mode by default. The strap feeder unit is operable to switch to the fixed mode in response to a precautionary event including detection of an aircraft mechanical failure by the mechanical failure sensor, thereby reducing freedom of movement of the occupant relative to the seat.

Abstract: An anti-torque system for a rotorcraft includes a first tail fan assembly including a plurality of first fan blades and a second tail fan assembly including a plurality of second fan blades. The first tail fan assembly has a larger diameter than the second tail fan assembly. The first fan blades have a larger rotational inertia than the second fan blades such that the second fan blades experience a larger angular acceleration than the first fan blades in response to torque, thereby providing yaw control for the rotorcraft.

Abstract: A propulsion system for a rotorcraft includes a first fan assembly including a plurality of first fan blades, a second fan assembly including a plurality of second fan blades and a drive system adapted to provide torque to the first and second fan blades. The first fan blades have a larger rotational inertia than the second fan blades. The second fan blades are adapted to experience a larger angular acceleration than the first fan blades in response to torque from the drive system, thereby providing responsive thrust control for the rotorcraft.

Abstract: An anti-torque system for a rotorcraft includes a first tail fan assembly including a plurality of first fan blades, a second tail fan assembly including a plurality of second fan blades and a motor adapted to provide torque to the first and second fan blades. The first fan blades have a larger rotational inertia than the second fan blades. The second fan blades are adapted to experience a larger angular acceleration than the first fan blades in response to torque from the motor, thereby providing responsive yaw control for the rotorcraft.

Abstract: A modal restraint system for an occupant of a seat of an aircraft having a mechanical failure sensor includes a strap feeder unit and a strap selectively retractable into and extendable from the strap feeder unit. The strap is positionable adjacent to the occupant. The strap feeder unit is adapted to switch between a plurality of modes including an unfixed mode and a fixed mode. The strap is extendable from and retractable into the strap feeder unit in the unfixed mode. The strap is substantially unextendable from the strap feeder unit in the fixed mode. The strap feeder unit is in the unfixed mode by default. The strap feeder unit is operable to switch to the fixed mode in response to a precautionary event including detection of an aircraft mechanical failure by the mechanical failure sensor, thereby reducing freedom of movement of the occupant relative to the seat.

Abstract: A modal restraint system for an occupant of a seat of an aircraft includes a strap feeder unit and a strap selectively retractable into and extendable from the strap feeder unit. The strap is positionable adjacent to the occupant so as to dispose the occupant between the strap and the seat. The strap feeder unit is adapted to switch between a plurality of modes including a fixed mode and an unfixed mode. The strap is substantially unextendable from the strap feeder unit in the fixed mode. The strap is extendable from and retractable into the strap feeder unit in the unfixed mode. The strap feeder unit is in the fixed mode by default. The strap feeder unit is operable to switch to the unfixed mode in response to a user input, thereby increasing freedom of movement of the occupant relative to the seat of the aircraft.

Abstract: A modal restraint system for an occupant of a seat of an aircraft includes a strap feeder unit and a strap selectively retractable into and extendable from the strap feeder unit. The strap is positionable adjacent to the occupant so as to dispose the occupant between the strap and the seat. The strap feeder unit is adapted to switch between a plurality of modes including an unfixed mode and a fixed mode. The strap is extendable from and retractable into the strap feeder unit in the unfixed mode. The strap is substantially unextendable from the strap feeder unit in the fixed mode. The strap feeder unit is in the unfixed mode by default. The strap feeder unit is operable to switch to the fixed mode in response to a precautionary event, thereby reducing freedom of movement of the occupant relative to the seat of the aircraft.

Abstract: An anti-torque system for a rotorcraft includes a first tail fan assembly including a plurality of first fan blades, a second tail fan assembly including a plurality of second fan blades and a motor adapted to provide torque to the first and second fan blades. The first fan blades have a larger rotational inertia than the second fan blades. The second fan blades are adapted to experience a larger angular acceleration than the first fan blades in response to torque from the motor, thereby providing responsive yaw control for the rotorcraft.

Abstract: A rotorcraft comprises a fuselage, a tail boom, a rotor system, and a centrifugal blower system. The centrifugal blower system comprises a centrifugal blower configured to generate thrust using an airflow, wherein the centrifugal blower is located within the tail boom. The centrifugal blower system also comprises a plurality of ducts configured to control the thrust generated by the centrifugal blower, wherein the plurality of ducts is located on a portion of the tail boom surrounding the centrifugal blower, and wherein the plurality of ducts comprises one or more adjustable ducts configured to vary a size of an associated duct opening.

Abstract: A power system for an aircraft includes a plurality of power consumers each operable to consume power in a range from zero to maximum power demand and collectively capable of consuming a combined maximum power demand, a power source operable to output power to the power consumers and a power allocation system operable to allocate power from the power source to the power consumers based on an operational parameter of the aircraft. The power allocated by the power allocation system is less than the combined maximum power demand of the power consumers, thereby allowing the power source to have a maximum power output less than the combined maximum power demand of the power consumers.

Abstract: An active cooling system includes a sensor configured to monitor a status of a lubrication system of a lubricated component and a cowling configured to cover at least a portion of the lubricated component. The cowling includes an inlet panel configured to move from a normal operating position to a cooling position, wherein the cooling position creates an air inlet configured to increase airflow passing by the lubricated component. The active cooling system further includes an actuator configured to initiate movement of the inlet panel from the normal operating position to the cooling position.

Abstract: A propulsion system for a rotorcraft includes a first fan assembly including a plurality of first fan blades, a second fan assembly including a plurality of second fan blades and a drive system adapted to provide torque to the first and second fan blades. The first fan blades have a larger rotational inertia than the second fan blades. The second fan blades are adapted to experience a larger angular acceleration than the first fan blades in response to torque from the drive system, thereby providing responsive thrust control for the rotorcraft.

Abstract: A power system for an aircraft includes a plurality of power consumers each operable to consume power in a range from zero to maximum power demand and collectively capable of consuming a combined maximum power demand, a power source operable to output power to the power consumers and a power allocation system operable to allocate power from the power source to the power consumers based on an operational parameter of the aircraft. The power allocated by the power allocation system is less than the combined maximum power demand of the power consumers, thereby allowing the power source to have a maximum power output less than the combined maximum power demand of the power consumers.

Abstract: A modal restraint system for an occupant of a seat of an aircraft includes a strap feeder unit and a strap selectively retractable into and extendable from the strap feeder unit. The strap is positionable adjacent to the occupant so as to dispose the occupant between the strap and the seat. The strap feeder unit is adapted to switch between a plurality of modes including an unfixed mode and a fixed mode. The strap is extendable from and retractable into the strap feeder unit in the unfixed mode. The strap is substantially unextendable from the strap feeder unit in the fixed mode. The strap feeder unit is in the unfixed mode by default. The strap feeder unit is operable to switch to the fixed mode in response to a precautionary event, thereby reducing freedom of movement of the occupant relative to the seat of the aircraft.