An FMS flight management computer equipping an aerodyne, complies with a constraint, in particular an altitude constraint, of the flight plan at an imposed waypoint close to the position of the aerodyne at the moment of instigation of its automatic flight plan following function. 14 or less, enabling the separation by specific gravity difference, and this is used as a covering material for an electric wire or cable to be high in flame retardancy. The cooling system may also have a plurality of orifice plates located between the pump and the heat exchanger. The quad electrodes receive electrical potential to form the field required to focus and maintain the ions at the center of the channel.