HELICOPTER ROTOR BLADES

摘要

A helicopter rotor blade (11) includes at its outer end (35) a tip vane (15) having a mean chord length greater than fifty per cent of a chord length of a blade central portion and a span length (25) greater than fifty per cent of the blade chord which in operation generates two approximately equal strength tip vortices to reduce an acoustic impulse and a resulting noise known as blade slap.