AD/PT6T/2 - Check and Regulating Valve Housing Reinforcing Bracket - CANCELLED

What this does: This officially cancels a previous aviation safety rule (Airworthiness Directive AD/PT6T/2) that required operators to inspect or replace the reinforcing bracket on the check and regulating valve housing of Pratt & Whitney Canada PT6T turbine engines.

Who it affects: Aircraft operators and maintenance organisations using Pratt & Whitney PT6T engines (commonly found in helicopters such as the Bell 412 and aircraft like the de Havilland Canada DHC-6 Twin Otter).

Why it matters: The original directive required compliance with Service Bulletin No. 5063 before January 1975. This cancellation removes that legal obligation entirely, effective from 2 July 2009. This suggests the safety issue addressed by the original 1970s-era requirement has been resolved through retirement of affected components, fleet turnover, or alternative safety measures.