FAA Proposes AD on Eurocopter EC135 Variants’ Main Gearbox

The FAA proposes a new airworthiness directive for the Eurocopter EC135P1, EC135P2, EC135P2+, EC135T1, EC135T2 and EC135T2+. It requires analyzing the main gearbox (MGB) oil for indications of metal chips or pieces, reviewing the MGB log or equivalent record, and inspecting certain teeth in the MGB after two chip indications. The proposed actions are intended to detect wear in the MGB that could lead to a gear tooth rupture, failure of the MGB, loss of power to the main rotor, and subsequent loss of control of the helicopter.