### ALERT SERVICE BULLETIN

Timken 1 st Stage Reduction Sun & Planet Gears
P/N’s: E3024765 & E3101455-02 Revision: B Issued: Nov. 7, 2011

File: T-804_Rev_B Page 1 of 2 This specification is property of TIMKEN. Statemen ts such as “as agreed with TIMKEN” or “as approved by TIMKEN” require authorization from TIMKEN Engine ering.

Timken Alcor Aerospace Technologies, Inc. 3110 N. Oakland, Mesa, Arizona 85215 

## T-804 ALERT SERVICE BULLETIN

Subject: Increased monitoring of chip detector. Removal of T imken Alcor Aerospace Technologies, Inc. (“TAATI”) PMA sun and planet gea rs TAATI Part Number(s): E3024765 & E3101455-02 Engine Application(s): Pratt and Whitney Canada PT6A-15AG, -27, -28, -34, -34AG, -34B, -36 Revision History: Rev. B dated 11/07/2011

REASON:

Rev. A of T-804 alert service bulletin (issued Augu st 29, 2011) applied to Timken Alcor Aerospace Technologies, Inc. (“ TAATI ”) PMA sun gear (P/N E3024765), serial numbers PC5- 091 through PC5-176. Subsequently, the FAA issued Airworthiness Directiv e 2011-20-51 (Sept. 15, 2011) (“ AD ”), which applied to the same serial numbers as initial T-804 alert serv ice bulletin. The FAA AD remains in effect for thos e serial numbers. This revision (Rev. B) expands the applicability of the T-804 alert service bulletin to include additi onal first stage reduction sun gears and planet gears manufact ured by TAATI.

Failure of the 1 st stage sun or planet gear may result in damage to t he reduction gear system and a possible In Flight Shutdown, creating a risk of pro perty damage, serious injuries, or fatality.

APPLICABILITY:

This Rev. B to alert service bulletin T-804 is appl icable to TAATI PMA sun gear (P/N E3024765) and PMA planet gear (P/N E3101455-02).

Affected serial numbers for each part number are :

P/N E3024765: Serial numbers PC5-090 and earlier and SG36-120 and earlier P/N E3101455-02: Set serial numbers EE-197 and ear lier, EE-4094 and earlier, and EE-4113

ACCOMPLISHMENT INSTRUCTIONS:

1. Inspect chip detector for collected debris within 1 0 operating hours following receipt of this alert service bulletin and at every 25 operating ho urs thereafter until the affected sun and planet gears are removed from service in accordance with i nstruction #2 and TCH maintenance manual instructions . If debris is observed, determine if the debris is allowable or non-allowable according to the applicable TCH maintenance manual. If the debris is considered non-allowable, remove the affected sun and planet gears in accordance with instruction #2.

### ALERT SERVICE BULLETIN

Timken 1 st Stage Reduction Sun & Planet Gears
P/N’s: E3024765 & E3101455-02 Revision: B Issued: Nov. 7, 2011

File: T-804_Rev_B Page 2 of 2 This specification is property of TIMKEN. Statemen ts such as “as agreed with TIMKEN” or “as approved by TIMKEN” require authorization from TIMKEN Engine ering.

Timken Alcor Aerospace Technologies, Inc. 3110 N. Oakland, Mesa, Arizona 85215 

## T-804 ALERT SERVICE BULLETIN

2. Remove the affected sun gear or planet gears from s ervice in accordance with the TCH maintenance manual within the earliest to occur of: (a) 60 operating hours after receipt of this alert service bulletin, (b) 60 days after receipt of this alert service bulletin, or (c) as required by instruction #1. At the same time, remove the interacting (mating) planet or sun gears. Replace the removed sun and planet gears with a complete zero t ime, first stage reduction sun gear and planet gear matched set.

Contact TAATI customer service and obtain a RMA num ber, then return the affected sun gear or planet gear to TAATI.

_________________ Record compliance with this alert service bulletin in the applicable section of the engine log book at initial and final inspection and at removal of the sun and planet gears. The entry should include part number, serial number and a reference to SB #T-804 Rev. B.

You may contact Timken to request a log sheet to he lp document all intermediate inspections performed in accordance with this alert service bulletin.

APPROVAL:

This document is FAA approved.