Summary
This NPRM proposes the supersedure of 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 action would require 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 proposal is prompted by an accident in which a Model SA.315B helicopter blade failed due to fatigue cracking. The proposed actions are intended to prevent separation of a blade and subsequent loss of control of the helicopter.