AD FAA-2012-0005

We are adopting an airworthiness directive (AD) for the Eurocopter France (ECF) Model AS332L2 helicopter and superseding an AD for the Model EC225LP helicopter. This AD is prompted by the manufacturer issuing additional corrective action to prevent failure of the main gearbox (MGB) due to the degradation of the epicyclic module of the MGB and expands the applicability to include the ECF Model AS332L2 helicopter because an investigation showed a failure within the epicyclic reduction gear module resulted in the rupture of the MGB case and separation of the main rotor head of a model AS332L2 helicopter in 2009. These actions are intended to prevent failure of the MGB and subsequent loss of control of the helicopter.