Aircraft braking system

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.