AD/PT6A/7 - Re-Routing Of Governor Air Pressure Line - CANCELLED

What this does: This document cancels an earlier aircraft safety rule (called an Airworthiness Directive or AD) that applied to specific Pratt & Whitney Canada PT6A turbine engines.

Who it affects: Aircraft operators and maintenance organisations that use or service these engines—commonly found in regional airliners, cargo aircraft, and agricultural planes.

What has changed: The previous rule required mechanics to re-route a specific air pressure line (the governor air pressure line) whenever installing a re-conditioned engine that had been overhauled after April 1966. As of 2 July 2009, this requirement no longer applies.

Why it matters: This reduces regulatory burden by removing an outdated maintenance obligation. The original rule addressed a specific safety issue identified in the 1960s, but the Civil Aviation Safety Authority has determined it is no longer necessary—likely because the affected engine population has been modified, retired, or the risk is now managed through other means.