Abstract: A clutch assembly for an aircraft drive wheel drive system to move an aircraft independently on the ground is provided. The clutch is mounted within an aircraft drive wheel to be operatively engaged and disengaged to selectively actuate a roller traction or other drive system to activate a non-engine drive means to drive the wheel and the aircraft. One embodiment of the clutch assembly includes a plurality of pivoted sprag elements selectively activatable to transmit torque between inner and outer clutch members and activate the drive wheel drive system. The clutch assembly may also include mating crown gear and straight gear elements integrated with the drive system to reduce stresses on the drive system as the drive means is actuated. Various arrangements of sprags and clutch assembly components may be provided to monitor and selectively control disengagement of the clutch assembly and communicate disengagement to selectively prevent drive system actuation.

Abstract: A vehicle wheel drive assembly, particularly useful in an aircraft, is provided. The vehicle wheel drive assembly is mounted completely within a space defined by structural dimensions of a vehicle wheel and includes a drive means controllable to power the wheel and move the vehicle autonomously on a ground surface, a gear assembly drivingly connected to the drive means, and a clutch assembly operatively connected to the gear assembly. The clutch assembly is operatively mounted with respect to the gear assembly completely within an interior portion of a vehicle wheel axle on which the wheel drive assembly is mounted, thereby maximizing the space functionally available for all of the other components of the wheel drive assembly.

Abstract: A method for reducing aircraft turnaround time by improving airport ramp safety is provided. The method minimizes the time interval between an aircraft's landing and takeoff by independently moving the aircraft on the ground without the aircraft's engines by eliminating hazards from jet blast, the possibility of engine ingestion, and the time previously required to wait in the gate area upon arrival or at departure until jet blast or engine ingestion did not pose a danger. Turnaround time is further reduced by providing an onboard driver controllable to drive at least one of the aircraft's wheels between landing and takeoff, thereby eliminating the need for a tow vehicle and the time required to move the aircraft with a tow vehicle.

Abstract: A method for accelerated power push back of an aircraft equipped with a pilot-controlled engines-off taxi system that drives the aircraft without reliance on the aircraft's main engines or tugs is provided. An aircraft is quickly and efficiently moved out of a gate where it is positioned in a nose-in orientation. The pilot controls the taxi system to drive the aircraft in reverse along a perpendicular path away from the terminal to a location where there is sufficient space for the aircraft to stop and turn, and the aircraft is turned and driven in a forward direction to a takeoff runway. Pilot reliance on ground personnel guidance during push back maneuvers is minimized by providing a monitoring system designed to monitor gate and ramp areas around the aircraft in any visibility or environmental conditions and provide feedback to the pilot.

Abstract: A surface travel system for military aircraft is provided that enables efficient, quiet, and safe ground operations of one or more aircraft in a wide range of military missions and operations. The surface travel system includes controllable onboard drive means that effectively drives one or more of the aircraft's wheels to move the aircraft autonomously, efficiently, quietly, and safely on any travel surface required for a military mission. The present invention allows the rapid safe deployment of multiple aircraft from tight spaces and enhances the readiness and availability of aircraft for a wide range of military operations.

Abstract: A powered aircraft wheel is designed to include multiple wheel sections configured to define a cavity within the wheel and to support completely within the wheel cavity an onboard non-engine drive means controllable to move an aircraft autonomously without reliance on aircraft engines during taxi and ground travel. Each part of the powered wheel may be constructed of a material specifically selected to emphasize a functional property of the material that is optimal for the function of the wheel part at a specific location. The selected combination of functionally distinct materials gives the powered aircraft wheel a unique optimal structural and functional capability.

Abstract: A powered clutch assembly is provided for an aircraft landing gear or other vehicle wheel drive system equipped with wheel drive motors controllable to move the aircraft or vehicle during ground travel. Electric power for the clutch assembly is transferred to clutch actuation elements by a rotary power transfer assembly mounted between stationary and rotating elements within the landing gear wheel drive system to clutch actuation elements. Actuation elements are powered to securely lock clutch rotating elements when required to improve the reliability of failsafe operation of the clutch assembly when torque should not be transferred and to unlock clutch rotating elements when torque should be transferred when the landing gear wheel drive system is used to drive the aircraft during ground travel. Power transferred from the rotary power transfer assembly may also be used to operate components associated with the aircraft drive wheel other than the powered clutch assembly.

Abstract: A method is provided for restoring mobility to an aircraft equipped with at least one self-propelled drive wheel powered by a driver when the aircraft has been rendered immobile as a result of one or more wheel tires adhering to and becoming stuck to tarmac or another ground surface. The method uses forces generated by the cooperative action of the wheel driver, the aircraft steering, and the aircraft braking system to release adherent tires of each set of main wheels and/or nose gear wheels by applying differential force to one set of wheels at a time to release any adherent tires so that the aircraft is able to move on the ground surface and travel in a desired direction at a desired speed.

Abstract: A method for increasing and optimizing the value of airport terminal exterior advertising is provided that significantly increases exposure of exterior advertising displays on the airside or non-public side of an airport terminal to passengers on arriving, parked, and departing aircraft. The movement of aircraft equipped with non-engine drive means on landing gear wheels for autonomous ground movement is controlled within an airport ramp area so that the aircraft moves in only a forward direction toward and away from a terminal parking place and parks in an orientation parallel to the terminal. The direction and orientation of aircraft ground travel and parking parallel to a terminal enhances and improves the visibility of exterior advertising displays to a maximum percentage of the passengers in the aircraft as the aircraft travels within the ramp area and parks between arrival and departure.

Abstract: A clutch driven aircraft electric taxi system is provided with a clutch assembly designed to be automatically selectively engaged or disengaged as required to drive an aircraft autonomously during ground operations. The clutch assembly is mounted integrally with other electric taxi system components completely within an aircraft landing gear wheel and may be designed with one way overrunning or selectable clutch engagement capability in one or both rotational directions, preferably using an arrangement of ratcheting struts and clutch elements adapted specifically for use in an aircraft landing gear drive wheel environment. The clutch assembly may automatically disengage in response to predetermined defined conditions or operating parameters.

Abstract: A method for maximizing traction in an aircraft drive wheel powered by non-engine drive means controllable to move the aircraft on the ground without reliance on the aircraft's brakes and dependence on friction defined by a mu-slip curve. The non-engine drive means is operated to control wheel speed and maintain the powered drive wheel in a maximized optimal traction condition when driving torques are applied to the drive wheel. Traction can be automatically maximized and maintained within an optimal range defined by a relationship between slippage and braking for maximum efficiency of aircraft ground travel under a wide variety of surface, weather, temperature, tire, and other conditions.

Abstract: An improved monitoring and control system capable of providing automatic control of ground movement in an aircraft equipped with non-engine drive means for autonomous ground movement to enhance airport ground safety and efficient ground travel is provided. The monitoring and control system is installed on aircraft equipped with non-engine drive means controllable to move the aircraft autonomously on the ground and includes monitoring means positioned in locations on the aircraft selected to obtain a maximum amount of information relating to an aircraft's ground position and operation, processor means, data transmission means, and manual or automatic control means to control and direct operation of an aircraft's non-engine drive means to move the aircraft autonomously, safely and efficiently on the ground. The improved monitoring and control system can be employed with one or a number of aircraft simultaneously to increase safety and efficiency of airport ground operations.

Abstract: A method for reducing aircraft turnaround time by improving airport ramp safety is provided. The method minimizes the time interval between an aircraft's landing and takeoff by independently moving the aircraft on the ground without the aircraft's engines by eliminating hazards from jet blast, the possibility of engine ingestion, and the time previously required to wait in the gate area upon arrival or at departure until jet blast or engine ingestion did not pose a danger. Turnaround time is further reduced by providing an onboard driver controllable to drive at least one of the aircraft's wheels between landing and takeoff, thereby eliminating the need for a tow vehicle and the time required to move the aircraft with a tow vehicle.

Abstract: A traction control system and method are provided for electric vehicles with at least one drive wheel powered by an electric drive motor to maintain optimum maximum traction while the vehicle is driven on the ground. The traction control system includes drive means capable of transmitting torque through a vehicle drive wheel and controllable to move the vehicle over a ground surface. A preferred drive means is an electric motor designed to move the vehicle at desired ground speeds in response to operator input. Operator input requests a desired speed, and the system determines drive wheel torque required to produce the desired speed and provides maximum current to produce maximum torque to drive the vehicle with optimum traction at the desired speed. The system uses constant feedback to find maximum current corresponding to torque required for an inputted speed request to automatically control traction in any electric powered vehicle.

Abstract: A method for maximizing traction in an aircraft drive wheel powered by non-engine drive means controllable to move the aircraft on the ground without reliance on the aircraft's brakes and dependence on friction defined by a mu-slip curve. The non-engine drive means is operated to control wheel speed and maintain the powered drive wheel in a maximized optimal traction condition when driving torques are applied to the drive wheel. Traction can be automatically maximized and maintained within an optimal range defined by a relationship between slippage and braking for maximum efficiency of aircraft ground travel under a wide variety of surface, weather, temperature, tire, and other conditions.

Abstract: An identification system and method are provided for aircraft equipped with electric taxi systems for autonomous ground movement that enables airport ground personnel and others outside the aircraft to safely and easily identify the aircraft moving on ground surfaces at an airport as equipped with a pilot-controlled electric taxi system and to distinguish these aircraft from aircraft not moved by electric taxi systems. The identification system may be mounted with nose or main landing gear drive wheels supporting the electric taxi system. The identification system includes an identifying lighting system with lighting elements of a selected number, shape, color, or arrangement positioned on at least a visible face of one or more landing gear wheels. Automatic or manual controls may actuate the identification system to identify electric taxi system-equipped aircraft when the aircraft are moved with the electric taxi system or are stopped.

Abstract: An efficient system and method are provided wherein aircraft may be retrofitted with non-engine drive means controllable to power landing gear wheels to move the aircraft autonomously during ground movement without engines or tow vehicles so that existing landing gear structures are employed to achieve force distribution and load transfer. Non-engine drive means capable of powering a landing gear wheel to move the aircraft during taxi are integrated into existing landing gear designs so that excess drive forces are transferred and distributed through previously evaluated and certificated landing gear structures, including tow fittings, determined to be capable of handling such forces, which eliminates changes to the landing gear and facilitates retrofit and certification. Engines-off taxi technology can be rapidly designed and developed to be retrofitted on existing aircraft nose and/or main landing gear and then efficiently certificated.

Abstract: An airport terminal gate traffic management system is provided that maximizes efficiency and safety of passenger transfer and aircraft servicing and minimizes aircraft time parked at a terminal. Aircraft are driven forward into and out of gates by controllable landing gear wheel non-engine drive means and parked in a parallel or perpendicular orientation relative to the terminal that facilitates passenger transfer through a maximum number of aircraft doors. Passenger transfer and aircraft servicing may begin upon aircraft arrival using all available accessible aircraft doors. Departing aircraft may be turned by an unassisted pilot and driven forward with the controllable non-engine drive means to a takeoff runway. Airport terminal aircraft gate traffic is most effectively and efficiently managed when a significant number of aircraft using an airport are equipped with non-engine drive means controllable to move them into and out of a parking orientation optimal for passenger transfer.

Abstract: Control of aircraft steering during ground travel is provided in an aircraft equipped with an engines-off wheel drive system controllable to move the aircraft autonomously on the ground without reliance on the aircraft's main engines or external tow vehicles. The wheel drive system is designed to interact with the aircraft's nose wheel hydraulic steering system to augment or replace the hydraulic steering system with the operation of the wheel drive system at taxi speeds, particularly at very low taxi speeds and even when the aircraft is stopped, to steer the aircraft as it maneuvers through turns during ground travel between landing and takeoff and at other times.

Abstract: A system and method is provided for improving efficiency of aircraft gate services and reducing time spent by an aircraft parked parallel to an airport terminal wherein aircraft utilities and gate services provided during turnaround are supported by an arrangement of flexibly movable, service and utility-carrying extendable passenger boarding bridges that enable passenger and baggage exchange concurrently with connection of utilities and provision of gate services to the aircraft. Baggage transfer is facilitated by conveyors mounted on one or more loading bridges and designed to provide a direct connection between an aircraft and a terminal. Aircraft are maneuvered by a pilot into and out of a parallel parking location in a forward direction by an engines-off electric taxi system, enabling loading bridge, utility, and service connections to be made to multiple aircraft doors as soon as the aircraft reaches a parking location and then quickly disconnected upon departure.