USE OF AUXILIARY RUDDERS FOR YAW CONTROL AT LOW SPEED
First Claim
1. A rotorcraft comprising:
- an airframe includinga cabin portion supporting flight controls and a seat to receive a pilot,a tower portion fixed to the cabin portion and extending upward therefrom,an empennage extending from proximate the cabin portion away therefrom,a first horizontal stabilizer mounted to the empennage, a first rudder secured to pivot with respect to the first horizontal stabilizer, anda vertical stabilizer connected to the empennage;
a rotor rotatably mounted to the tower to rotate about an axis of rotation offset from the vertical stabilizer and first horizontal stabilizer;
a propulsion source mounted to the airframe and directing air flow across the vertical stabilizer;
a first auxiliary rudder mounted to the vertical stabilizer and spaced from the first horizontal stabilizer; and
a controller receiving yaw control inputs from a pilot and selectively actuating the auxiliary rudders in response to the yaw control inputs exclusively at airspeeds of the rotorcraft below an airspeed threshold.
12 Assignments
0 Petitions
Accused Products
Abstract
Apparatus and methods for controlling yaw of a rotorcraft in the event of one or both of low airspeed and engine failure are disclosed. 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.
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Citations
20 Claims
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1. A rotorcraft comprising:
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an airframe including a cabin portion supporting flight controls and a seat to receive a pilot, a tower portion fixed to the cabin portion and extending upward therefrom, an empennage extending from proximate the cabin portion away therefrom, a first horizontal stabilizer mounted to the empennage, a first rudder secured to pivot with respect to the first horizontal stabilizer, and a vertical stabilizer connected to the empennage; a rotor rotatably mounted to the tower to rotate about an axis of rotation offset from the vertical stabilizer and first horizontal stabilizer; a propulsion source mounted to the airframe and directing air flow across the vertical stabilizer; a first auxiliary rudder mounted to the vertical stabilizer and spaced from the first horizontal stabilizer; and a controller receiving yaw control inputs from a pilot and selectively actuating the auxiliary rudders in response to the yaw control inputs exclusively at airspeeds of the rotorcraft below an airspeed threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A rotorcraft comprising:
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an airframe including first and second horizontal stabilizers mounted to the airframe, each of the first and second horizontal stabilizers having a rudder mounted thereto, and a vertical stabilizer mounted to the airframe between the first and second horizontal stabilizers; a rotor rotatably mounted to the airframe and rotatable about an axis of rotation, the axis of rotation offset from the vertical stabilizer and first and second horizontal stabilizers; a propulsion system mounted to the airframe and oriented to direct air flow over the vertical stabilizer; an auxiliary rudder mounted to the vertical stabilizer positioned between the first and second horizontal stabilizers; and a controller programmed to receive yaw control inputs from a pilot and to actuate the auxiliary rudders in response to the yaw control inputs only for airspeeds of the rotorcraft below an airspeed threshold. - View Dependent Claims (12, 13, 14, 15)
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16. A rotorcraft comprising:
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an airframe including a cabin portion supporting flight controls and a seat to receive a pilot, a tower portion fixed to the cabin portion and extending upward therefrom, first and second empennages extending from proximate the cabin portion away therefrom, first and second horizontal stabilizers mounted to the first and second empennages, respectively, first and second rudders secured to pivot with respect to the first and second horizontal stabilizers, respectively, and a vertical stabilizer connected to extend between the first and second empennages; a rotor, rotatably mounted to the tower to rotate about an axis of rotation offset from the vertical stabilizer and first horizontal stabilizer; a propulsion source mounted to the airframe and directing air flow across the vertical stabilizer; a first auxiliary rudder mounted to the vertical stabilizer and spaced from the first horizontal stabilizer; and a controller receiving yaw control inputs from a pilot and selectively actuating the first auxiliary rudder in response to the yaw control inputs exclusively at airspeeds of the rotorcraft below an airspeed threshold. - View Dependent Claims (17, 18, 19, 20)
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Specification