Airworthiness Directives; Hartzell Propeller Inc. ()HC-()2Y(K,R)-() Series Propellers

The FAA is superseding an existing airworthiness directive (AD) for Hartzell Propeller Inc. ()HC-()2Y()-() series propellers with non-suffix serial number (SN) propeller hubs installed on Lycoming O-, IO-, LO-, and AEIO-360 series reciprocating engines. That AD currently requires initial and repetitive eddy current inspections (ECIs) of the front cylinder half of the propeller hub for cracks and removing cracked hubs from service before further flight. In addition, that AD allows installation of an improved design propeller hub (suffix SN "A" or "B") as terminating action to the repetitive ECI. This ad requires the same actions but changes the affected propeller series designation to ()HC-()2Y(K,R)-() series propellers with non-suffix SN propeller hubs and suffix SN letter "E" propeller hubs. This AD also expands the engine eligibility to include Lycoming LIO-, TO-, LTO-, AIO-, and TIO-360-series engines. This AD results from the need to make changes to the affected series designation of propellers, to expand the engine applicability, and to respond to comments received on AD 2006- 18-15. We are issuing this AD to prevent failure of the propeller hub causing blade separation and subsequent loss of airplane control.