Measurement of Ice Accretion Using Ultrasonic Pulse-Echo
Techniques
Aircraft icing remains one of the most severe aviation weather hazards. A system to measure aircraft
ice accretion and accretion rate in real time could directly reduce this hazard. Real-time
measurement of ice accretion rate can provide the pilot with a quantitative evaluation of icing
severity. Therefore, the effectiveness of changes in flight path to minimize ice accretion can be
determined. In addition, an automatic measuring system system measuring ice accretion on critical
components such as wings, engine inlets, propellers, or rotor blades could be used to automatically
activate and optimally control ice protection systems. Although many schemes have been suggested
for measuring aircraft ice accretion,1-3 there is still a need for a practical system
capable of real-time in situ measurement of ice accretion. The purpose of this study
is to evaluate the feasibility and potential performance of an ice detection system using pulsed
ultrasonic waves to measure ice thickness over a small transducer mounted flush with the aircraft
surface. Since the technique of ultrasonic "pulse-echo" thickness measurement produces a real-time
ice thickness signal, the ice accretion rate may be determined by electronically differentiating this
thickness measurement with respect to time.
--J. Hansman, Jr., and M. S. Kirby, "Measurement of Ice Accretion Using Ultrasonic Pulse-Echo Techniques," Proceedings, American institute of Aeronautics and Astronautics