It adds weight and changes the shape of the airfoil, either of which could spell disaster. Engineers at New Avionics Corp., Ft. Lauderdale (newavionics.com), developed an ice probe, the Icemeister (Model 9732), that can detect as little as 0.001 in. of ice, alerting pilots to its presence before it becomes a danger. This lets the pilot avoid icing conditions or engage anti-icing measures when they can do the most good. The probe can also be networked with autopilots and other systems that automatically start deicing equipment.
The simple device bounces an IR laser off a transparent dome that protrudes outside the aircraft skin or any other place icing is a problem (such as engine inlets) to the outside. The reflected signal is altered by ice on the outside of the dome. This change is detected by simple electronic circuitry. The 1 ⁄4-oz device has no moving parts, is radio silent (no MHz clock), and is hermetically sealed. It runs on 3.3 V and consumes less than 100 mA.