Airworthiness Directives; Eurocopter France Model AS355E, F, F1, F2, and N Helicopters

This amendment supersedes an existing airworthiness directive (AD) for the specified Eurocopter France (Eurocopter) model helicopters. The existing AD currently requires certain checks of the magnetic chip detector plug (chip detector) and the main gearbox (MGB) oil-sight glass; and certain inspections of the lubrication pump (pump) and replacing the MGB and the pump with an airworthy MGB and pump, if necessary. Also, the AD requires that a before a MGB or pump with any time-in-service (TIS) can be installed, it must meet the AD requirements. This amendment requires the same actions as the existing AD but corrects the wording to state that the check of the chip detector is for sludge rather than metal particles. This amendment is prompted by the need to correct the wording because the term "metal particles" may be misleading. The actions specified by this AD are intended to detect sludge on the chip detector, to prevent failure of the MGB pump, seizure of the MGB, loss of drive to an engine and main rotor, and subsequent loss of control of the helicopter.