Full-Scale Testing of a Centrifugally Powered Pneumatic De-Icing System for Helicopter Rotor Blades

A centrifugally powered pneumatic de-icing system was developed and tested. Two prototype designs were fabricated and parametrically tested at representative icing conditions. The superior performing design was able to remove ice thicknesses as small as 0.078 in. at and 0.112 in. at . This configuration was reproduced and installed on the outboard 8 ft section of a full-scale 24 ft K-MAX blade. Full-scale icing tests were conducted at Kaman's outdoor whirl tower using a custom portable icing cloud generator to produce a controlled icing cloud as well as a secondary cloud generator that produced large, uncontrolled water droplets. During full-scale icing tests, the de-icing system was able to remove ice thicknesses as small as 0.08 in. at 270 rpm. A method to calculate power drawn from the main rotor during de-icing system operation is presented. During depressurization, the system draws a peak power of 4.15 hp from the rotor and 0.02 hp during pressurization. The total weight of the de-icing system is comparable to that of existent erosion caps installed on in-service helicopters.