# US 2023/0264809 A1 · Aircraft braking system

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- Number: US 2023/0264809 A1
- Document ID: US20230264809A1
- Status: Published application
- Kind: A1
- Application number: 18/172,234
- Filed: 2023-02-21
- Published: 2023-08-24
- Earliest claimed: 2022-02-21
- Assignees: Airbus Operations GmbH
- Applicants: Airbus Operations Limited
- Inventors: Julian GALE; Ashley BIDMEAD; Andrew HEBBORN
- Web page: https://patentgrep.com/patent/US20230264809A1

## CPC

- B64C 25/426: {Braking devices providing an automatic sequence of braking}
- B60T 7/04: foot actuated
- B60T 8/1703: {for aircrafts}
- B60T 8/325: {Systems specially adapted for aircraft}
- B60T 8/58: responsive to speed and another condition or to plural speed conditions
- B60T 2250/04: Vehicle reference speed; Vehicle body speed
- Y02T 50/80: Energy efficient operational measures, e.g. ground operations or mission management
- B64C: AEROPLANES; HELICOPTERS
- B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A method of parking an aircraft is disclosed including flight crew pedal braking to cause a brake force to be applied to the aircraft wheel brakes to slow the aircraft to a stationary state in which it is ready to be parked. Flight crew then activate a parking brake device and then release the pedal braking. An electronic control device, forming part of the aircraft’s braking system for example, automatically intervenes, following the manual release of the pedal braking, to cause a brake force to continue to be applied to the wheels. This may be until sufficient brake force is applied, as a result of the activation of the parking brake device, to hold the aircraft in its parked state or may be for a predetermined period of time, say, ten seconds.

## Claims

### Claim 1

A method of operating an aircraft, the aircraft comprising
a first brake system for one or more wheels of the aircraft, the first brake system having a first input device which is manually controllable to generate a braking command which causes a braking force to be applied that can be different values across a range of braking forces allowing the amount of braking applied to the one or more wheels to be varied under manual control of the first input device from zero to full braking,
a second brake system for one or more wheels of the aircraft, the second brake system having a second input device which is manually controllable to activate an aircraft parking mode in which a braking force sufficient to hold the aircraft stationary in a parked state is applied to one or more wheel brakes, and which is manually controllable to de-activate the aircraft parking mode so that the braking force is reduced to a level at which the aircraft is released from such a parked state,
the method comprising steps of
manually using the first input device to command the application of braking to one or more wheels of the aircraft by the first brake system when the aircraft is in a state ready to be parked and/or to slow the aircraft to such a state,
manually using the second input device to activate the aircraft parking mode, while the first input device continues to be manually used to command the application of braking,
after the aircraft parking mode has been activated, manually using the first input device to generate a lower or zero braking command,
an electronic control device overriding the lower braking command, if certain first pre-set criteria are met, so that the braking force applied by the first braking system is higher than so commanded, and
holding the aircraft in a parked state with use of the second braking system.

### Claim 2 (depends on 1)

A method according to claim 1, wherein
the first brake system is a pedal brake system, and
the first input device is a pedal brake.

### Claim 3 (depends on 1)

A method according to claim 1, wherein the method includes a step of the electronic control device ceasing, if certain second pre-set criteria are met, its overriding of the braking command, if any, from the first input device.

### Claim 4 (depends on 3)

A method according to claim 3, wherein the second pre-set criteria used by the electronic control device include whether a time period has elapsed, the time period being determined by a pre-set delay after the time at which the second input device is used to activate the aircraft parking mode.

### Claim 5 (depends on 3)

A method according to claim 3, wherein the second pre-set criteria used by the electronic control device include the level of braking commanded by the second brake system.

### Claim 6 (depends on 3)

A method according to claim 3, wherein the second pre-set criteria used by the electronic control device include the level of braking force being applied under the command of the second brake system.

### Claim 7 (depends on 1)

A method according to claim 1, wherein the first pre-set criteria used by the electronic control device include the speed of the aircraft and/or whether the aircraft is in take-off mode.

### Claim 8 (depends on 1)

A method according to claim 1, wherein the first pre-set criteria used by the electronic control device include whether a park brake system fault is detected.

### Claim 9 (depends on 1)

A method according to claim 1, wherein the first pre-set criteria are such that the electronic control device initially overrides the lower braking command if the electronic control device determines, in view of one or more input signal(s) received at the electronic control device, that
(a) the aircraft is not in take-off mode, and
(b) the aircraft is not moving at a speed of more than a threshold speed, the threshold speed being less than 15 knots, and wherein
the electronic control device continues to override the lower braking command for at least five seconds after the time at which the second input device is used to activate the aircraft parking mode, unless the electronic control device determines in view of one or more input signal(s) received at the electronic control device that
(c) the second input device has been used to deactivate the aircraft parking mode for a time longer than a threshold time, the threshold time being less than 5 seconds, or
(d) the level of braking force being applied under the command of the second brake system is higher than a pre-set threshold.

### Claim 10 (depends on 1)

A method according to claim 1, being performed as part of a method of parking an aircraft, wherein
the step of manually using the first input device is performed by flight crew pressing one or more brake pedals to cause brake force to be applied to the brakes of one or more wheels of the aircraft when the aircraft is ready to be parked,
the step of manually using the second input device is performed by flight crew activating a parking brake device,
the step of manually using the first input device to generate a lower or zero braking command, after the aircraft parking mode has been activated, is performed by flight crew then releasing the one or more brake pedals,
the step of the electronic control device overriding the lower braking command is performed by the electronic control device automatically intervening, following the releasing of the brake pedal(s) by the flight crew, to cause the brake force to be applied by the first braking system at least until sufficient brake force is applied, as a result of the activation of the parking brake device, to hold the aircraft in its parked state.

### Claim 11

An electronic control device for use when effecting braking of the wheels of an aircraft, the aircraft comprising
a first brake system for braking one or more of the wheels, the first brake system having a first input device which is manually controllable by flight crew to generate a braking command which causes a braking force to be applied that can be different values across a range of braking forces allowing the amount of braking applied to the one or more wheels to be varied under manual control of the first input device from zero to full braking, and
a second brake system for braking one or more of the wheels, the second brake system having a second input device which is manually controllable by flight crew to activate an aircraft parking mode in which a braking force sufficient to hold the aircraft stationary in a parked state is applied to one or more wheel brakes, and which is manually controllable by flight crew to de-activate the aircraft parking mode so that the braking force is reduced to a level at which the aircraft is released from such a parked state,
the electronic control device being configured to
monitor the braking command demanded by the first brake system and/or a level of braking actually applied by the first brake system,
monitor the braking command demanded by the second brake system and/or a level of braking actually applied by the second brake system,
apply, in the event that certain first pre-set criteria are met, a higher level of braking by the first brake system than would otherwise be applied, and
cease to apply, in the event that certain second pre-set criteria are met, said higher level of braking by the first brake system,
the first pre-set criteria including both (a) the flight crew activating the aircraft parking mode with the use of the second input device and (b) there being a premature reduction in the braking command demanded by the first brake system and/or in the level of braking actually applied by the first brake system, and
the second pre-set criteria including (c) whether the aircraft parking mode is demanded by the second input device active and (d) whether it can be concluded that a braking force sufficient to hold the aircraft stationary in the parked state is being applied to one or more wheel brakes.

### Claim 12 (depends on 11)

An electronic control device according to claim 11, wherein the control device receives an input from which the control device can determine whether a park brake has been activated by flight crew.

### Claim 13 (depends on 11)

An electronic control device according to claim 11, wherein the control device receives an input from which the control device can determine whether pedal braking is active.

### Claim 14 (depends on 11)

An electronic control device according to claim 11, wherein the control device receives an input from which the control device can determine aircraft ground speed or whether the aircraft ground speed meets certain speed criteria.

### Claim 15 (depends on 11)

An electronic control device according to claim 11, wherein the control device receives an input from a braking force sensor which detects the brake pressure or brake force applied by one of the brake systems of the aircraft.

### Claim 16 (depends on 11)

An electronic control device according to claim 11, wherein the control device receives an input from which the control device can determine whether a parking brake fault exists.

### Claim 17 (depends on 11)

An electronic control device according to claim 11, wherein the control device uses a clock signal to ascertain whether a certain amount of time has elapsed from the time when the flight crew last activated the aircraft parking mode with the use of the second input device.

### Claim 18 (depends on 11)

An electronic control device according to claim 11, wherein the aircraft is a commercial fixed-wing passenger aircraft configured to carry at least 50 passengers.

### Claim 19 (depends on 1)

A computer program product comprising instructions which, when the program is executed by a programmable control device, cause the control device to carry out the function of the electronic control device of the method of claim 1.

### Claim 20 (depends on 11)

A computer program product comprising instructions which, when the program is executed by a programmable control device, cause the control device to carry out the function of the electronic control device of claim 11.
