Airworthiness Directives; Pratt & Whitney Canada Turboprop Engines

This amendment adopts a new airworthiness directive (AD) that applies to Pratt & Whitney Canada (PWC) engine models PW118, PW118A, PW118B, PW119B, PW119C, PW120, PW120A, PW121, PW121A, PW123, PW123B, PW123C, PW123D, PW123E, PW123AF, PW124B, PW125B, PW126, PW126A, PW127, PW127B, PW127E, PW127F, PW127G, PW127H, and PW127J turboprop engines. This amendment requires replacing certain Stewart Warner part number (P/N) fuel heaters, installed on PWC engines, with redesigned fuel heaters. This amendment is prompted by several field incidents in which one or more of the three studs that attach the fuel filter bowl to the fuel heater have been partially or completely pulled free of the fuel heater housing. We are issuing this AD to prevent the separation of the fuel filter bowl from the fuel heater, which could result in a pressurized fuel leak and possible engine fire.