Method of training a neural network to control an aircraft system

A method of training a neural network to control an aircraft braking system having a plurality of aircraft braking system components, the method comprising:

• obtaining an aircraft braking system operational mode data space representing a set of operational modes for the aircraft braking system, wherein each operational mode represents a configuration of the aircraft braking system where performance of one or more of the plurality of aircraft braking system components is impaired, according to a model of the aircraft braking system, wherein the plurality of aircraft braking system components comprise one or more of a power supply selector valve and an actuator;
• obtaining probability data indicative of probabilities of the operational modes occurring, wherein each of the probabilities is positive and greater than a zero probability;
• comparing obtained probability data for each operational mode to a theoretical operational probability threshold, wherein each of the probabilities is greater than a zero probability;
• removing operational modes having a probability less than or equal to the theoretical operational probability threshold from the aircraft braking system operational mode data space to leave behind a reduced aircraft braking system operational mode data space, wherein the reduced aircraft braking system operational mode data space is limited to the operational modes from the operational mode data space having a probability greater than the theoretical operational probability threshold and excludes the operational modes in the operational mode data space having a probability equal or less than the theoretical operational probability threshold;
• comparing obtained probability data for operational modes within the reduced aircraft braking system operational mode data space to a real-world operational probability threshold;
• removing operational modes having a probability greater than or equal to the real-world operational probability threshold from the reduced aircraft braking system operational mode data space to leave behind a training aircraft braking system operational mode data space, wherein the operational modes remaining in the training aircraft braking system operational mode data space is limited to the operational modes in the reduced aircraft braking system operational mode data space having a probability less than the real-world operational probability threshold;
• and
• training the neural network using operational modes within the training aircraft braking system operational mode data space, to control reconfiguration of the braking system by controlling one or more of the power supply selector valve and the actuator.