Airworthiness Directives; Eurocopter Deutschland (Eurocopter) Model EC135 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-12-01, which was sent previously to all known U.S. owners and operators of Eurocopter Model EC135 helicopters by individual letters. This AD requires initial and repetitive visual inspections and one dye-penetrant inspection of the main rotor hub shaft (shaft) for cracks. If a crack is found during any of the inspections, this AD requires replacing the shaft with an airworthy shaft before further flight. This amendment is prompted by the discovery of fatigue cracks on the shaft of a helicopter. The actions specified by this AD are intended to detect fatigue cracks in the shaft that could lead to shaft failure and subsequent loss of control of the helicopter.