Airworthiness Directives; MD Helicopters Inc. Model MD900 Helicopters

This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc. Model MD900 helicopters. This action requires installing a fan input force limiting control rod assembly fail-safe device (fail-safe device). This AD also requires, after installing a fail-safe device, before the first flight of each day, checking the fail-safe device for bent clips, taut lanyards, and piston rod movement. If any of these conditions are found, this AD requires replacing the control rod assembly with an airworthy control rod assembly before further flight. This amendment is prompted by an accident report of fatigue failure of the piston rod in the spring capsule on a control rod assembly. The actions specified in this AD are intended to provide a temporary backup support system in the event of a piston rod failure and to prevent subsequent loss of control of the helicopter.