Airworthiness Directive · Amendment 39-16843 · Pratt & Whitney Canada PT6A-15AG, -27, -28, -34, -34AG, -34B, and -36 Series Turboprop Engines
Pratt & Whitney Canada PT6A-15AG, -27, -28, -34, -34AG, -34B, and -36 Series Turboprop Engines
This AD applies to Pratt & Whitney Canada PT6A-15AG, -27, -28, -34, -34AG, -34B, and -36 series turboprop engines that have had maintenance done to the power section module involving first stage reduction sun gear replacement since February 3, 2010, and having a Timken Alcor Aerospace Technologies, Inc. (TAATI) part manufacturer approval (PMA) replacement first stage reduction sun gear, part number (P/N) E3024765, serial numbers (S/Ns) PC5-091 through PC5-176, installed.
We are adopting a new airworthiness directive (AD) for Pratt & Whitney Canada PT6A-15AG, -27, -28, -34, -34AG, -34B, and -36 series turboprop engines. This emergency AD was sent previously to all known U.S. owners and operators of these engines. This AD requires the removal of affected part manufacturer approval (PMA) replacement Timken Alcor Aerospace Technologies, Inc. (TAATI) first stage reduction sun gears and the interacting planet gears, from the propeller reduction gearbox assembly. This AD was prompted by failures of certain PMA replacement first stage reduction sun gears, manufactured by TAATI. We are issuing this AD to correct the unsafe condition on these products.
For affected engines, remove the PMA replacement TAATI first stage reduction sun gear and the interacting planet gears from the propeller reduction gearbox assembly within 15 operating hours or 15 days after the effective date of this AD, whichever occurs first.
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 reduction sun gear, P/N E3024765, S/Ns PC5-091 through PC5-176.
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.
