Aircraft Icing Potential and Ice- and Mixed-phase Cloud Microphysics

AbstractCold cloud interactions with aircrafts that fly through them require knowledge of cloud microphysics. Aircrafts must be designed to fly into supercooled clouds, or they must avoid those clouds in order to prevent problems associated with airframe and engine icing. De-icing or anti-icing systems must be engineered to withstand reasonable extremes in terms of ice water content (IWC), supercooled liquid water content (LWC), ice particle size distributions (SDs), and temperature. The aircraft design or certification envelopes (FAR 25, Appendix C; Federal Aviation Administration, 1999) were developed before the advent of modern cloud physics instrumentation. In the case of ice and mixed-phase clouds, data from the aircraft measurements during recent field campaign suggest that cloud temperature is one of the main parameters governing cloud microstructure, the size distributions, and the current icing potential (CIP). This study may help improve airplane icing prediction through better understanding of the ice microphysical properties.