AD FAA-2012-0416

We are superseding an existing airworthiness directive (AD) for all Pratt & Whitney Canada Corp. (P&WC) PW118, PW118A, PW118B, PW119B, PW119C, PW120, PW120A, PW121, PW121A, PW123, PW123B, PW123C, PW123D, PW123E, PW123AF, PW124B, PW125B, PW126A, PW127, PW127E, PW127F, PW127G, and PW127M turboprop engines. That AD currently requires initial and repetitive inspections of certain serial numbers (S/Ns) of propeller shafts for cracks and removal from service if found cracked. This new AD requires the same actions, but requires removal from service of affected propeller shafts as mandatory terminating action to the repetitive inspections. This AD was prompted by reports of two propeller shafts found cracked at time of inspection during maintenance. We are issuing this AD to detect propeller shaft cracks, which could cause failure of the shaft, propeller release, and loss of control of the airplane.