Continental C-90

Airworthiness Directives; Teledyne Continental Motors Models C75, C85, C90, C125, C145, O-200, O-300, and GO-300 Series and Rolls-Royce, plc C90, O-200 and O-300 Series Reciprocating Engines

This amendment revises an existing airworthiness directive (AD), applicable to Teledyne Continental Motors (TCM) Models C75, C85, C90, C125, C145, O-200, O-300, and GO-300 series reciprocating engines, that currently requires inspection of the cylinder rocker shaft bosses for cracks, and inspection of the cylinder rocker shaft for looseness and replacement, if necessary, with a serviceable part. This amendment clarifies that the inspection must be accomplished at the next cylinder removal from the engine or engine overhaul, whichever occurs first, and adds certain Rolls-Royce, plc engines to the AD's applicability. This amendment is prompted by the need to clarify when the inspection must be performed. The actions specified by this AD are intended to prevent engine power loss and engine failure.