# BULLETIN INDEX LOCATOR 

# 72-50-05 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF MODEL APPLICATION PT6C-67C Commercial Support Program No: 1005964 Compliance: 3, 3, 3 Summary: A baffle located on the Power Turbine (PT) shaft housing cover may move out of position and contact the downstream side of the second stage PT disk. This is because a retaining ring holding the Power Turbine (PT) baffle in place may become loose. An initial and recurring borescope inspection is required to confirm if the retaining ring and the PT baffle are correctly in place. 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Cover Sheet

24-Hour Global Service USA & CANADA........................ **1-800-268-8000** Other .......................................... **1-450-647-8000** 

### CFIRST CENTRE International .................... **(IAC*)+8000-268-8000** Fax ............................................. **1-450-647-2888** Toll free where available (SIL GEN-027) * International Access Code Web Site .................................. **www.pwc.ca**WARNING - PROPRIETARY RIGHTS & EXPORT CONTROLS NOTICE This bulletin contains proprietary information of Pratt & Whitney Canada Corp. (′′ P&WC′′), which P&WC provides in confidence and solely for the purposes of supporting engine certification and providing applicable information regarding the proper use, maintenance, inspection, repair, servicing and parts application of P&WC products and services, as directed therein. Neither this bulletin nor any information in it may be disclosed to others, or used for any other purpose, including, without limitation, to design, create, develop, reproduce, manufacture or derive any design, part, product, material, process, modification, configuration change or repair, or obtain FAA or other government approval to do so. Possession and use of this bulletin is also subject to the restrictions set out in P&WC’s Technical Data Agreement (a copy of which may be obtained by contacting P&WC Technical Publications). The contents of this bulletin may be subject to export control laws. Unauthorized export or re-export of the bulletin, or parts thereof, is prohibited. By accepting and possessing this bulletin, you agree to be bound by the foregoing terms. If a Government agency or department intends to disclose any information, written notice should be given to: VP - Legal Services, Pratt & Whitney Canada Corp., 1000 Marie-Victorin (01BE5), Longueuil, Quebec J4G 1A1.

**Export Control Classification** *Data is subject to the jurisdiction of the Export and Import Controls Bureau of the Department of Foreign Affairs and International Trade of Canada, Department of Commerce of the United States and/or Department of State of the United States. ** Data is not subject to the jurisdiction of the Department of Commerce of the United States or Department of State of the United States but would become subject if exposed to any US involvement. **Regulation Classification Number**  Canadian ECL(s)* ECCN(s)* P-ECCN(s)** 9E991 USML (ITAR)* P-USML**REVISION TRANSMITTAL SHEET TURBOSHAFT ENGINE MODEL PT6C

SUBJECT: Pratt & Whitney Canada Service Bulletin No. PT6C-72-A41060, Rev. No. 3, dated Oct 11/2012 (P&WC S.B. No. A41060R3) RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF
Replace your existing copy of this service bulletin with the attached revised bulletin. Destroy the superseded copy. Please retain this Revision Transmittal Sheet with the revised bulletin. SUMMARY: This revision is issued to:

v delete the Note in para. 1E that stated ‘‘For engines that are past the above interval....’’, and

v change the format of the compliance code shown on the title page from Compliance:

CATEGORY 3 TO Compliance 3, 3, 3.
EFFECT OF REVISION ON PRIOR ACCOMPLISHMENT: None. NOTE: A black bar in the left margin indicates a change in that line of text or figure.
REVISION HISTORY: Original Issue: Aug 12/2011 Revision No. 1: Sep 29/2011 Revision No. 2: Feb 10/2012 Revision No. 3: Oct 11/2012 Pratt & Whitney Canada Corp. 1000, Marie-Victorin Longueuil, Québec, Canada J4G 1A1 Tél. 450-677-9411
11 October 2012 P&WC S.B. No. A41060R31. Planning Information A. Effectivity PT6C-67C Engines Pre-SB41056. NOTE: 1. Engines that were shipped from a P&WC Service Center after June 15/2011 are already compliant for the first inspection of this Service Bulletin but they must comply with the repetitive inspection requirement. NOTE: 2. Engines that had Special Instruction 45-2011 accomplished are already compliant for the first inspection of this Service Bulletin but they must comply with the repetitive inspection requirement. NOTE: 3. The repetitive inspections per SB A41059 are no longer required after embodiment of this SB. NOTE: 4. Engines Serial Number KB0562, KB0850 and KB0856 are already compliant for the first inspection of this Service Bulletin but they must comply with the repetitive inspection requirement. B. Concurrent Requirements None. C. Reason (1) Problem A baffle located on the Power Turbine (PT) shaft housing cover may move out of position and contact the downstream side of the second stage PT disk. (2) Cause A retaining ring holding the Power Turbine (PT) baffle in place may become loose. (3) Solution Do an initial and recurring borescope inspection to confirm that the PT baffle and the retaining ring are correctly in place. D. Description Do a borescope inspection to confirm if the retaining ring and the PT baflle are correctly installed. This SB must be performed under the direct supervision of a trained P&WC representative or by personnel that have received specific training for this inspection. P&WC No. DCR13892, DCR17606 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 1 of 14 © 2011 Pratt & Whitney Canada Corp. PRINTED IN CANADA TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF1. Planning Information (Cont’d) E. Compliance **For engines with more than 2000 PT cycles:** CATEGORY 3 - P&WC recommends to do this SB within 100 flight hours or 150 PT cycles whichever comes first and recurring inspections every 600 flight hours or 900 PT cycles whichever comes first. **For engines between 1000 and 2000 PT cycles:** CATEGORY 3 - P&WC recommends to do this SB within 250 flight hours or 350 PT cycles whichever comes first and recurring inspections every 600 flight hours or 900 PT cycles whichever comes first. **For engines with less than 1000 PT cycles:** CATEGORY 3 - P&WC recommends to do this SB within 500 flight hours or 750 PT cycles whichever comes first and recurring inspections every 600 flight hours or 900 PT cycles whichever comes first. NOTE: 1. The PT cycles equals Current Cycles on the Second Stage PT disk. NOTE: 2. For engines that are already compliant with the first inspection of this service bulletin based on the note in para. 1.A. (Effectivity), the flight hours and PT cycles to be considered for the first inspection are the ones from the last shop visit. F. Approval D.A.A. approved G. Manpower Once you have access to the part, an estimate of 1.0 man-hours is required to include this service bulletin at maintenance. H. Weight and Balance None. I. Electrical Load Data Not changed. J. Software Accomplishment Summary Not applicable. 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 2 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF1. Planning Information (Cont’d) K. References None. L. Publications Affected None. M. Interchangeability and Intermixability of Parts Interchangeability - Refer to Para. 2.C. Intermixability - Not changed. 2. Material Information A. Industry Support Information Refer to Commercial Support Program Notification (CSPN) No. 1005964. Refer to SIL PT6C-012 to schedule a visit of a P&WC representative or MRT. B. Material - Cost and Availability Not applicable. C. Material Necessary for Each Engine Not applicable. D. Reidentified Parts None. E. Tooling - Price and Availability
Tool No. Nomenclature Est. Price ($US,) Delivery None Fiberscope with 1.0 mm fiber diameter or less and a minimum of 600 mm in length (Ref. Fig. 1). NA Commercially Available 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 3 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF2. Material Information (Cont’d)
Tool No. Nomenclature Est. Price ($US,) Delivery None Guide and Pointer Tool (Ref. Fig. 1 and 4). NA Provided by P&WC 3. Accomplishment Instructions **WARNING:** ENGINE MUST BE COOL PRIOR TO DOING THIS PROCEDURE. **CAUTION:** THIS PROCEDURE MUST BE PERFORMED UNDER THE DIRECT SUPERVISION OF A TRAINED P&WC REPRESENTATIVE OR BY PERSONNEL THAT HAVE RECEIVED SPECIFIC TRAINING FOR THIS INSPECTION. **CAUTION:** THE BORESCOPE IS FRAGILE. HANDLE WITH CARE TO AVOID DAMAGE AND DO NOT BEND EXCESSIVELY. **CAUTION:** DO NOT ROTATE THE POWER TURBINE WHILE DOING THIS PROCEDURE. IF THE ENGINE IS INSTALLED, DO NOT ROTATE THE MAIN OR TAIL ROTOR. A. Do the borescope inspection as follows: (1) For installed engines or engines ready to be installed on the airframe, the airframe primary exhaust nozzle bolted to the engine exhaust port flange must be removed (Ref. Fig. 2). Refer to the airframe maintenance manual. (2) Gain access to the engine exhaust port (Ref. Fig. 3). (3) Insert the pointer tool between the platforms of the 2nd stage PT blades and the exhaust hub at TDC position. Make sure the tip of the pointer tool is pointing toward the center of the engine. Apply tape over the pointer tool to prevent it from moving. NOTE: Contact P&WC if the pointer tool cannot be inserted properly. It might be because the PT baffle ass’y has moved out of position. (4) Insert the borescope fiber and manoeuver the fiber in the cavity between the 2nd stage PT disk and the baffle to locate the retaining ring. (5) Verify that the retaining ring is in position. (6) Repeat above steps at approximatly 135 deg from TDC (on more accessible side). 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 4 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF3. Accomplishment Instructions (Cont’d) (7) If the retaining ring is missing or the PT Baffle out of position, return the engine to P&WC. (8) Complete the Inspection Form (Ref. Fig. 9) attached and send it by E-mail or Fax to:

v E-mail: GP.PWC.PT6.Series.Turboshaft.SE@pwc.ca

v Fax: 450-647-9597 B. Write accomplishment of P&WC S.B. No. 41060 in the applicable engine module log book. 4. Appendix 

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# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 5 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OFC194090 Fiberscope with guide tool installed Figure 1 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 6 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF**AIRFRAME PRIMARY EXHAUST NOZZLE** 

C184820 Primary Exhaust Nozzle Figure 2 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 7 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OFC185421 Engine Exhaust Port Figure 3 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 8 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OFC194092 Second Stage PT Blades and Exhaust Hub Figure 4 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 9 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF**INSERT FIBER HERE EXHAUST HUB** 

**COVER P/N 3070467−01** 

**RETAINING RING P/N AS3217−215**  **BAFFLE P/N 3070555−01** 

C184823 Retaining Ring Location - Engines Pre-SB41056 Figure 5 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 10 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OFC194093 Retaining Ring Installed - Engines Pre-SB41056 Figure 6 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 11 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF**BAFFLE P/N 3070555−01** 

**RETAINING RING P/N AS3217−215** 

**RETAINING RING IN PLACE**

**RETAINING RING REMOVED BAFFLE**  **P/N 3070555−01**

C194094 Retaining Ring Missing - Engines Pre-SB41056 Figure 7 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 12 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF**POINTER TOOL COVER** 

**RETAINING RING PT DISK** 
**PT BAFFLE LIP**

**RETAINING RING IN PLACE**

**RETAINING RING MISSING (SIMULATED BORESCOPE VIEW)**  **DISLODGED PT BAFFLE POINTER TOOL**  **COVER**

**PT BAFFLE LIP COVER**  **PT DISK**

C194095

PT Baffle Figure 8 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 13 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF

## INSPECTION FORM

**ENGINE S/N: ENGINE TSN:** 
**AIRCRAFT S/N (IF INSTALLED): ENGINE POSITION (IF INSTALLED):**  **INSPECTION DATE: INSPECTION LOCATION:**  **INSPECTION PERFORMED BY: P&WC FSR INVOLVED:**  **RETAINING RING IN PLACE: YES**  **NO COMPANY NAME:** 



### Complete the Inspection Form and send it by E−mail or Fax to: **E−mail: GP.PWC.PT6.Series.Turboshaft.SE@pwc.ca FAX: 450−647−9597**  **OPERATOR /OWNER NAME:**

**SECOND STAGE PT DISK CYCLES:**

C188086 Inspection Form Figure 9 

### PRATT & WHITNEY CANADA 

# ALERT SERVICE BULLETIN P&WC S.B. No. A41060R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator The export control classification with respect to this document is contained on the back of the locator. Aug 12/2011 **PT6C-72-A41060** Revision No. 3: Oct 11/2012 Page 14 of 14 TURBOSHAFT ENGINE RETAINING RING, POWER TURBINE BAFFLE - INSPECTION OF