I have a pipe dream in which the TAS would be detected by a kind of anemometer mounted at a suitable point on the fuselage. Provided the static pressure and TAT were available, the ADC could then calculate the CAS/IAS, and of course the Mach. But an anemometer might be even more prone to icing than a pitot head, and its RPM could be problematic...
Yes, probably.
What about a 'tongue' made of suitable material sticking out perpendicular to the aircraft fuselage which has no moving parts and which is bent back by the airflow? There would be no pipe to get blocked by insects or ice, and one would just measure the amount of bend electrically caused by the airflow to compute airspeed. You would heat the tongue to keep it de-iced, but this arrangement seems much more robust to me.
Any instrumentation designers or engineers care to comment?