Passive Robust Airspeed Sensing for Uncrewed Aircraft Systems in Icing Conditions

An airspeed system specifically developed for small uncrewed aircraft systems (UAS) is proposed and tested in a multiphase wind tunnel. The system measures dynamic pressure on the lee side of the probe geometry, thereby reducing vulnerability to icing, contamination, and precipitation and enabling operation without heating. The underlying concept relies on calibrated pressure coefficient differences that preserve a monotonic relationship with dynamic pressure. Wind tunnel experiments were conducted under controlled Appendix C icing conditions, as well as clean and dry reference cases. The results demonstrate reliable airspeed measurements in adverse environments, with only slightly reduced accuracy compared to nonicing conditions. Gradual performance degradation rather than abrupt failure was observed, while runback icing was identified as the most critical limitation.