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: According to one implementation of the present disclosure, a stabilizer of an aircraft includes an energy attenuating portion. The energy attenuating portion includes first and second edge sections separated by an adaptable section. The adaptable section may be rigid in a first range of directions and compressible in a second range of 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: According to one implementation of the present disclosure, a stabilizer of an aircraft includes an energy attenuating portion. The energy attenuating portion includes first and second edge sections separated by an adaptable section. The adaptable section may be rigid in a first range of directions and compressible in a second range of directions.

Abstract: According to one implementation of the present disclosure, a stabilizer of an aircraft includes an energy absorbing assembly. The energy absorbing assembly includes first and second portions and a retractable section. The retractable section may be at least partially affixed to the first portion and is configured to enable displacement of the second portion of the stabilizer with respect to the first portion.

Abstract: According to one implementation of the present disclosure, a stabilizer of an aircraft includes an energy attenuating portion. The energy attenuating portion includes first and second edge sections separated by an adaptable section. The adaptable section may be rigid in a first range of directions and compressible in a second range of directions.

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: The present invention includes a system and method for slowing the rotation of a rotor using, for example, rotor brake system for a rotorcraft comprising: 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 variable-speed gearbox for a tiltrotor with fixed engine and rotating proprotor includes an input shaft coupled to the respective fixed engine, an output shaft coupled to the respective proprotor; a high-speed clutch integrated into a high-speed gear train, the high-speed gear train having an input coupled to the input shaft and an output coupled to the output shaft; and a low-speed clutch integrated into a low-speed gear train, the low-speed gear train having an input coupled to the input shaft and an output coupled to the output shaft. The high-speed clutch and the low-speed clutch can be freewheeling clutches capable of disconnecting the output and the input of the respective gear train of the high and low-speed gear trains in an overrunning condition when the output rotates faster than the input of the respective gear train. The low-speed clutch can be permanently engaged. In accordance to some embodiments the variable-speed gearboxes may include an accessory drive.

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: According to one implementation of the present disclosure, a stabilizer of an aircraft includes an energy absorbing assembly. The energy absorbing assembly includes first and second portions and a retractable section. The retractable section may be at least partially affixed to the first portion and is configured to enable displacement of the second portion of the stabilizer with respect to the first portion.

Abstract: According to one implementation of the present disclosure, a stabilizer of an aircraft includes an energy attenuating portion. The energy attenuating portion includes first and second edge sections separated by an adaptable section. The adaptable section may be rigid in a first range of directions and compressible in a second range of directions.

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.