Aircraft icing caused by large supercooled droplets

Abstract

Substantial loss in rate of climb capability can result from less than 10 minutes duration in conditions where fewer than 0.1-1 cm-3 of droplets 30-400 μm in diameter are present. These conditions are found to have a greater effect than those where the liquid water was confined to smaller (generally less than about 30 μm diameter) droplets. Measurements from research aircraft flying in regions containing these large droplets, located in the Sierra Nevada in California, near Amarillo, Texas, and in northern Arizona are presented. Temperatures ranged from -5.5° to 9.4°C in 13 regions. The sizes of the droplets responsible for performance loss varied with each encounter but ranged from tens to hundreds of micrometers, and these were accompanied by few to no ice crystals. -from Author