Impact of Icing on Unmanned Aerial Vehicle (UAV) Operations

摘要

Clouds with supercooled liquid water constitute a significant aviation hazardbecause of the potential risk of air-craft icing. Icing reduces rate of lift, rate of climb, and fuel efficiency while increasing drag, stalling speed, weight, and power requirements. Indirectly, icing also exacts a penalty because on board icing detection/removal equipment may be required at the expense of other payload and because icing conditions may restrict launch/recovery or possible flight paths. All of these considerations can be of increased importance for unmanned aerial vehicle (UAV) operations because of the unique design features of some UAVs and because of the extra burden placed on autonomous control systems. Therefore, UAV operations will require strong icing forecast support and remote icing detector systems at the vehicle bases and possibly on the vehicles themselves. High flying long endurance UAVs will be able to fly above icing levels but are at special risk in ascending/descending through icing layers due to the degradation icing causes to the highly optimized wing shape of such vehicles. Low flying short endurance vehicles do not have such sensitive wing shapes but may not be able to fly above all icing layers. The high flyers may be able to ascend/descend over their bases and thus require remote sensors only at the bases, whereas low flyers may require on board sensors when they are out of base sensor range. A brief overview of the icing problem for UAvs will be given along with proposed solutions and potential needs, including improved dorecasting and reliable compact remote sensors.