Abstract: A method and apparatus for deicing aircraft wherein a deicing fluid tank is provided with partitions which establish a plurality of chambers for receiving a deicing fluid, such as water, and at least one chamber for receiving an anti-icing fluid, such as glycol. The fluid to be heated is withdrawn from a selected one of the fluid chambers, heated to a predetermined temperature such as 140.degree.-190.degree. F., and returned to the same chamber preparatory to application. The temperature of the fluid in adjacent chambers is raised somewhat by conduction. The various partitions provide limited flow communication between the fluid chambers such that as fluid is withdrawn from the selected primary chamber for application onto an aircraft, the fluid in adjacent chambers replenishes the removed fluid without substantially reducing the temperature of the fluid therein, thereby requiring minimal recovery time to maintain a temperature-ready supply of fluid for a deicing operation.

Abstract: A system for automatically limiting the maximum speed of a vehicle to a predetermined maximum, particularly suitable for use with off-road vehicles such as aircraft deicing trucks. The system utilizes a magnetic Hall effect sensor to generate a speed signal which is compared to a signal representative of a preselected maximum vehicle speed. In response to the comparison a pulse-width modulated control signal is generated and used to control a transistor in series with the ignition coil primary thereby intermittently disrupting the ignition system.

Abstract: Apparatus is disclosed for determining the proportion of ethylene glycol in an aqueous solution that is used to remove as well as prevent the accumulation of ice and snow on commercial aircraft, the apparatus being used in de-icing equipment of the type which has a self-propelled vehicle, a large capacity heater which heats water carried on the vehicle, a proportioning system for mixing the water and ethylene glycol and pumping means for pumping the solution containing the desired proportion of ethylene glycol under high pressure through a nozzle which is directed toward the aircraft. The apparatus can determine the percentage of ethylene glycol that is contained in the aqueous solution at any time during the operation of the de-icing equipment.

Abstract: A method for deicing an aircraft having ice formed on its outer skin comprises heating a water solution substantially free of glycol to a temperature from approximately 160.degree. to approximately 190.degree. F. The water is then sprayed in a stream onto the skin under atmospheric conditions whereby the heated water will loosen the ice and wash the ice from the skin. The excess water solutionwhich falls from the airplane is drained away. The heated water forms a film on the skin and warms the skin to prevent additional ice from forming thereon. Under certain atmospheric conditions, the heated water film will evaporate from the skin, thereby chilling the skin and drying it so as to minimize the sticking of blowing snow and ice on the skin. The method minimizes the amount of glycol required for anti-icing.