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US 10,479,481 B2Granted
Process and machine for reducing a drag component of a horizontal stabilizer on an aircraft
AssigneeThe Boeing Company
InventorHenry Llewellyn Beaufrere
Life of this patent
Estimating the term…
Abstract
A process and a machine for improving a performance of a particular model of an aircraft, via reducing a size of a horizontal stabilizer for the particular model of the aircraft, the process comprising augmenting a nose-up moment, for the particular aircraft model, provided by a reduced horizontal stabilizer for the particular aircraft model, via addition of an ailevatoron mixer.
Claims19
A flight control system for an aircraft, that comprises:
- tricycle configured landing gear that comprises main gear;
- wings mounted on, and separated from a horizontal stabilizer by, a fuselage, the horizontal stabilizer configured to generate a moment, about an axis defined by contact points of the main gear of the aircraft with a takeoff surface, in an aircraft nose-up direction;
- an ailevatoron, respectively on each wing of the wings, located aft of the axis and configured to generate, about the axis, an ailevatoron moment;
- an ailevatoron mixer that comprises a filter and a scheduler configured to:
- receive inputs that comprise:
- a flight control position, rotation speed criteria, aircraft performance, and flight control commands;
- determine, based upon the inputs, a rotation moment required to rotate a nose of the aircraft off the takeoff surface for takeoff;
- responsive to the moment generated by the horizontal stabilizer being less than the rotation moment, due to the horizontal stabilizer comprising a size reduced from a size originally designed to produce the rotation moment for the aircraft to takeoff with a maximum allowed nose-down take off weight moment without the ailevatoron mixer, determining a magnitude required for the ailevatoron moment, such that a sum of the moment produced by the horizontal stabilizer and the ailevatoron moment equals the rotation moment;
- determine a deflection, away from the takeoff surface, required for the ailevatoron, respectively on each wing of the wings, to generate a force that generates the magnitude required for the ailevatoron moment;
- and
- command the ailevatoron, respectively on each wing of the wings, to deflect away from the takeoff surface to the deflection determined.
8 more elements
A flight control system that comprises an ailevatoron mixer configured to produce an ailevatoron moment for an aircraft at takeoff, such that the aircraft comprises:
- a tricycle landing gear configuration that comprises two main gear and a nosewheel;
- a tail that comprises a horizontal stabilizer that comprises an elevator;
- wings mounted on opposite sides of, and separated from the tail by, a fuselage;
- an axis defined by contact points of the two main gear with a takeoff surface;
- a center of gravity located between the axis and the nosewheel of the aircraft, such that the center of gravity generates a weight moment about the axis that holds the nosewheel on the takeoff surface;
- an ailevatoron, respectively on each wing of the wings, located aft of the axis and configured to generate the ailevatoron moment about the axis;
- and
- the ailevatoron mixer comprising:
- a filter configured to receive:
- a weight on wheels signal, an airspeed, a pitch command, and a deflection of the elevator, of the aircraft;
- a scheduler configured to determine, responsive to the pitch command to rotate the aircraft for the takeoff and based upon a magnitude of the weight moment being greater than a magnitude of an aircraft nose-up pitch moment generated by the horizontal stabilizer, due to the horizontal stabilizer comprising a size reduced from a size originally designed to produce the required nose-up pitch moment to overcome the weight moment for the aircraft to takeoff without the ailevatoron mixer:
- a magnitude required for the ailevatoron moment;
- and
- a magnitude required for a symmetric deflection, away from the takeoff surface, of the ailevatoron, respectively on each wing of the wings, such that the ailevatoron moment supplements the aircraft nose-up pitch moment generated by the horizontal stabilizer sufficiently to generate a rotation moment that overcomes the weight moment and lifts the nosewheel off the takeoff surface for the aircraft to tho takeoff from the takeoff surface;
- a mixer configured to:
- receive:
- a roll command, and the magnitude required for the symmetric deflection;
- and
- mix the roll command with the magnitude required for the symmetric deflection to form a command to the ailevatoron, respectively on each wing of the wings, that generates the ailevatoron moment.
16 more elements
Dependencies are inferred from the claim text.