RINGS OF MIST ENCIRCLE U.S. PLANES. Officers and men aboard a U.S.

RINGS OF MIST ENCIRCLE U.S. PLANES. Officers and men aboard a U.S. aircraft carrier turn to watch as the whirring three-bladed propeller of a U.S. Navy Hellcat fighter plane, about to take off, rings the plane with halos of condensed moisture. The phenomenon, a rare sight which occurs only when atmospheric conditions are just right, is caused by a rapid change in pressure and a consequent sudden drop in temperature most pronounced at the tips of the propeller blades.