Airworthiness Directives; Turbomeca Arriel 1 Series Turboshaft Engines

We are revising an existing airworthiness directive (AD) for the products listed above. This AD was prompted by Turbomeca restoring all or part of the life limits of the affected discs, and European Aviation Safety Agency's (EASA) issuance of AD 2010-0101R2, dated March 24, 2011, to do the same. Turbomeca has introduced a reinforced eddy- current inspection (ECI) which, combined with a revised analysis, allows the life limit of the affected discs to be extended. We are issuing this revision to prevent failure of the gas generator (GG) second stage turbine disc which could result in the release of high energy debris and damage to the helicopter.