Airworthiness Directive · Amendment 39-17045 · Pratt & Whitney Canada Turboprop Engines
Pratt & Whitney Canada Turboprop Engines
This AD applies to Pratt & Whitney Canada PT6A-38, -41, -42, -42A, -61, -64, -66, -66B, -110, -112, -114, -114A, -121, -135, and -135A series turboprop engines:
(1) That have had maintenance done to the power section module involving first stage sun gear or planet gear replacement since December 22, 2008; and
(2) That have any of the following Timken Alcor Aerospace Technologies, Inc. (TAATI) part manufacturer approval (PMA) replacement first stage sun gears or planet gear sets installed:
(i) First stage sun gears P/N E3028456, all serial numbers (S/Ns).
(ii) First stage sun gears P/N E3037304, all S/Ns.
(iii) Planet gear sets P/N E3101455-02, all S/Ns.
(iv) Planet gear sets P/N E3101525-02, all S/Ns.
We are adopting a new airworthiness directive (AD) 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. This AD requires removal from service of certain part manufacturer approval (PMA) replacement Timken Alcor Aerospace Technologies, Inc. (TAATI) 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 TAATI. We are issuing this AD to prevent failure of the sun gear and planet gears which will result in an engine in-flight shut down, possible uncontained engine failure, aircraft damage, and serious injuries.
(1) Comply with this AD within the compliance times specified, unless already done.
(2) Within 40 operating hours after the effective date of this AD, remove from service the following PMA replacement TAATI first stage sun gear and the planet gears from the propeller reduction gearbox assembly:
(i) First stage sun gears P/N E3028456, all S/Ns, and the associated planet gears.
(ii) First stage sun gears P/N E3037304, all S/Ns, and the associated planet gears.
(iii) Planet gear sets P/N E3101455-02, all S/Ns, and the associated sun gears.
(iv) Planet gear sets P/N E3101525-02, all S/Ns, and the associated sun gears.
After the effective date of this AD, do not install on any airplane, any engine or power section module with a TAATI PMA replacement first stage sun gear or a planet gear set, as listed in paragraph (c) of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
