Airworthiness Directives; Hartzell Propeller Inc. ( )HC-( )(2,3)Y(K,R)-2 Two- and Three-Bladed Compact Series Propellers

The FAA is adopting a new airworthiness directive (AD) for Hartzell Propeller Inc. left-hand rotating ( )HC-( )(2,3)Y(K,R)-2 two- and three-bladed, aluminum hub, "compact" series propellers, with hubs having a non-suffix serial number, and lubrication holes located on the shoulder of the hub blade socket. These propellers are installed on Lycoming Engines LIO-360 series and LO-360 series reciprocating engines installed on Piper Aircraft, Inc. Seneca PA-34-200 and Seminole PA-44-180, and Hawker Beechcraft Corporation Model 76 Duchess, airplanes. This AD requires initial and repetitive eddy current inspections (ECI), of the area around the lubrication holes of the hub blade sockets. This AD results from four reports of propeller hub cracks, including two in-flight blade separation events. We are issuing this AD to prevent failure of the propeller hub, which could result in blade separation and loss of control of the airplane.