Airworthiness Directives; Pratt & Whitney Canada Model PT6A-67D Turboprop Engines

This amendment supersedes an existing airworthiness directive (AD), applicable to Pratt & Whitney Canada (PWC) PT6A-67D turboprop engines, that currently requires inspections of the compressor turbine (CT) disk and blades for cracking and other irregularities using visual inspections and fluorescent penetrant inspections (FPI). That AD also requires amending the Beech Model 1900D Airplane Flight Manual (AFM) and installing a placard that alerts the pilot of a requirement to restrict continuous engine operation above 94.0% and below 97.1% N1 (Gas Generator RPM). In addition, that AD requires the installation of parts having an improved design including a CT stator assembly, a CT shroud housing, CT turbine blades, feather seals, and a small exit duct assembly . This amendment continues the requirements of the current AD and adds the requirements to remove the placard from the cockpit and to remove the amendment to the AFM after installation of the improved engine components. This amendment is prompted by reports from operators and the manufacturer stating that the engine RPM operating restriction is not required after installation of the improved engine components, and that this engine operating restriction can impact aircraft handling. The actions specified by this AD are intended to prevent aircraft handling problems due to imposition of the engine RPM restriction.