Air Data Probe Anomalies in Flight Through Measured High Ice Water Content Conditions

temperature and airspeed readings during commercial and research flight operations. These anomalies occur when ice crystals are ingested into the heated probe inlet, melt or partially melt to liquid water, and then refreeze or remain in a liquid state depending on the probe heat and cloud conditions. In pitot probes, the refreezing may cause complete blockage of the total pressure, which causes airspeed anomalies. In total air temperature (TAT) probes, the melted ice water may flow near the temperature-sensing element and cause the TAT reading to approach 0 °C. During the High Ice Water Content (HIWC) RADAR and HIWC–2022 flight campaigns and the Convective Process Experiment–Cabo Verde (CPEX–CV) flight campaign, a total of 71 anomalies were recorded on the NASA DC–8 pitot probes when subjected to specific flight and cloud conditions. Similarly, a research TAT probe mounted near the pitot probes had 19 anomalies. This paper presents analyses of the measured natural conditions that led to these TAT and pitot anomalies, identifies two types of pitot probe anomalies, applies a concentration factor to estimate local TWC conditions near the TAT and pitot probes, and identifies the static air temperature and pressure altitude where the anomalies occurred on the Part 33, Appendix D envelope.