Airworthiness Directives; Eurocopter France Model SA.315B, SA.316B, SA.316C, SE.3160, and SA.319B Helicopters

This amendment supersedes an existing airworthiness directive (AD) for Eurocopter France (ECF) Model SA.315B, SA.316B, SA.316C, SE.3160, and SA.319B helicopters. That AD requires initial and recurring inspections of the main rotor blade (blade) spar for cracks. This amendment requires initial and recurring dye penetrant or eddy current inspections for a cracked blade spar at 100-hour time-in- service (TIS) intervals or 600 cycles, whichever occurs first, rather than the 25-hour TIS intervals currently required. This amendment is prompted by an accident in which an ECF Model SA.315B helicopter blade failed due to fatigue cracking. The actions specified by this AD are intended to prevent separation of a blade and subsequent loss of control of the helicopter.