POLISHED FROST?

摘要

One of winter flying's oddest traditions is that of "polishing" frost-instead of removing it entirely-to eliminate the greater drag the condition creates. Natural frost on a wing's upper surface is much rougher in texture than the wing itself. Polishing it, so the theory goes, removes that roughness and, supposedly, allows a safe departure. Except there's no data supporting this theory. And, according to the FAA, "the term 'polished frost' is ambiguous since no standard of acceptable smoothness is provided." So, the agency in May 2008 proposed a rule prohibiting takeoff with polished frost. At this writing, it appears the proposal has not yet been finalized.