PT6 Focus of New Airworthiness Directive

The FAA is adopting an airworthiness directive for certain Pratt & Whitney Canada PT6A-38, -41, -42, -42A, -61, -64, -66, -66B, -110, -112, -114, -114A, -121, -135, and -135A series turboprop engines. The AD requires the removal from service of certain PMA replacement parts from Timken Alcor Aerospace Technologies, including first-stage sun gears and planet gears installed in the reduction gearbox. This AD was prompted by failures of certain first-stage sun gears manufactured by Timken Alcor. These failures can result in an in-flight engine shut down, possible uncontained engine failure, aircraft damage and serious injuries.