Different wind conditions create different situations that
a helicopter is subjected to. For instance, a helicopter
flying at 90 knots in a zero-wind condition is equivalent to a
helicopter hovering in a 90-knot headwind. Since the rotating
main rotor blades are the helicopter’s ‘wings’ in flight, the
helicopter is flown most efficiently if the fuselage is kept
in trim with respect to the wind. This is true whether the
helicopter is in a headwind or tailwind condition
