BULLETIN INDEX LOCATOR

73-20-00

TURBOPROP ENGINE

POWER TURBINE CONTAINMENT RING MODIFICATION OF

MODEL APPLICATION

PT6A-20, PT6A-20A, PT6A-20B, PT6A-21, PT6A-25, PT6A-25A, PT6A-25C, PT6A-27, PT6A-28,

PT6A-34, PT6A-34AG, PT6A-34B, PT6A-36, PT6A-114, PT6A-135, PT6A-135A

Model(s) deleted this revision: PT6A-116

Compliance: CATEGORY 4

Summary: The existing power turbine containment ring is modified by installing a reinforcement

liner.

PRATT & WHITNEY CANADA

ALERT SERVICE BULLETIN

P&WC S.B. No. A1427R3

Feb 03/1988 PT6A-72-A1427

Revision No. 3: Jan 27/2012 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

TURBOPROP ENGINE MODEL PT6A

SUBJECT: Pratt & Whitney Canada Service Bulletin No. PT6A-72-A1427, Rev. No. 3, dated Jan

27/2012 (P&WC S.B. No. A1427R3) POWER TURBINE CONTAINMENT RING

MODIFICATION 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 service bulletin is revised to modify the compliance code and add alert.

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: Feb 03/1988

Revision No. 1: Feb 23/1989

Revision No. 2: Apr 03/1990

Revision No. 3: Jan 27/2012

Pratt & Whitney Canada Corp.

1000, Marie-Victorin

Longueuil, Québec, Canada J4G 1A1

Tél. 450-677-9411

27 January 2012

P&WC S.B. No. A1427R3

1. Planning Information

A. Effectivity

PT6A-20 Engines and all engines converted to Engine Model PT6A-20 (Ref. P&WC

engine conversion SB1267).

PT6A-20A Engines and all engines converted to Engine Model PT6A-20A (Ref. P&WC

engine conversion SB1268).

PT6A-20B Engines and all engines converted to Engine Model PT6A-20B (Ref. P&WC

engine conversion SB1206).

PT6A-21 Engines which are before and include Serial No. PCE-PCE-25361.

PT6A-25 Engines.

PT6A-25A Engines which are before and include Serial No. PCE-48757.

PT6A-25C Engines which are before and include Serial No. PCE-26258.

PT6A-27 Engines which are before and include Serial No. PCE-42523 and all engines

converted to Engine Model PT6A-27 (Ref. P&WC engine conversion SB1214).

PT6A-28 Engines and all engines converted to Engine Model PT6A-28 (Ref. P&WC

engine conversion SB1120).

PT6A-34 Engines which are before and include Serial No. PCE-57303 and all engines

converted to Engine Model PT6A-34 (Ref. P&WC engine conversion SB1499).

PT6A-34AG Engines which are before and include Serial No. PCE-57312 and all

engines converted to Engine Model PT6A-34AG (Ref. P&WC engine conversion

SB1252).

PT6A-34B Engines.

PT6A-36 Engines and all engines converted to Engine Model PT6A-36 (Ref. P&WC

engine conversion SB1405).

PT6A-114 Engines which are before and include Serial No. PCE-17218 excluding

17213.

PT6A-135 Engines.

PT6A-135A Engines which are before and include Serial No. PCE-35089.

B. Concurrent Requirements

None.

C. Reason

The existing power turbine containment ring is modified by installing a reinforcement

liner.

NOTE: Also some containment rings are modified to add scallops.

D. Description

The existing power turbine containment ring is modified by installing a reinforcement

liner, also some are modified to add scallops.

P&WC No. 35558, DCR

PRATT & WHITNEY CANADA

ALERT SERVICE BULLETIN

P&WC S.B. No. A1427R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator

Feb 03/1988 The export control classification with respect to this document is contained on the back of the locator. PT6A-72-A1427

Revision No. 3: Jan 27/2012 Page 1 of 7 © 1988 Pratt & Whitney Canada Corp.

PRINTED IN CANADA

TURBOPROP ENGINE

POWER TURBINE CONTAINMENT RING MODIFICATION OF
1. Planning Information (Cont’d)

E. Compliance

CATEGORY 4 - P&WC recommends to do this service bulletin the first time the engine

or module is at a maintenance base that can do the procedures,

regardless of the scheduled maintenance action or reason for engine

removal.

F. Approval

D.O.T./D.A.A. approved.

G. Manpower

Estimate of 1 man-hours required to include this service bulletin at overhaul.

H. Weight and Balance

None.

I. Electrical Load Data

Not changed.

J. Software Accomplishment Summary

Not applicable.

K. References

Illustrated Parts Catalog P/N 3015444 (PT6A-6, PT6A-6A, PT6A-6B, PT6A-20,

PT6A-20A, PT6A-20B)

Illustrated Parts Catalog P/N 3013244 (PT6A-21, PT6A-27, PT6A-28)

Illustrated Parts Catalog P/N 3027544 (PT6A-25, PT6A-25A)

Illustrated Parts Catalog P/N 3032144 (PT6A-25C)

Illustrated Parts Catalog P/N 3021244 (PT6A-34, PT6A-34AG, PT6A-34B, PT6A-36)

Illustrated Parts Catalog P/N 3043514 (PT6A-114, PT6A-114A, PT6A-135, PT6A-135A)

Overhaul Manual P/N 3011403 (PT6A-20, PT6A-20A, PT6A-20B)

Overhaul Manual P/N 3013243 (PT6A-21, PT6A-27, PT6A-28)

Overhaul Manual P/N 3027543 (PT6A-25, PT6A-25A)

Overhaul Manual P/N 3032143 (PT6A-25C)

Overhaul Manual P/N 3021243 (PT6A-34, PT6A-34AG, PT6A-34B, PT6A-35, PT6A-36,

PT6A-114, PT6A-114A, PT6A-135, PT6A-135A)

Part Digest No. 2992

PRATT & WHITNEY CANADA

ALERT SERVICE BULLETIN

P&WC S.B. No. A1427R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator

Feb 03/1988 The export control classification with respect to this document is contained on the back of the locator. PT6A-72-A1427

Revision No. 3: Jan 27/2012 Page 2 of 7

TURBOPROP ENGINE

POWER TURBINE CONTAINMENT RING MODIFICATION OF
1. Planning Information (Cont’d)

L. Publications Affected

Illustrated Parts Catalog P/N 3015444 (PT6A-6, PT6A-6A, PT6A-6B, PT6A-20,

PT6A-20A, PT6A-20B)

Illustrated Parts Catalog P/N 3013244 (PT6A-21, PT6A-27, PT6A-28)

Illustrated Parts Catalog P/N 3027544 (PT6A-25, PT6A-25A)

Illustrated Parts Catalog P/N 3032144 (PT6A-25C)

Illustrated Parts Catalog P/N 3021244 (PT6A-34, PT6A-34AG, PT6A-34B, PT6A-36)

Illustrated Parts Catalog P/N 3043514 (PT6A-114, PT6A-114A, PT6A-135, PT6A-135A)

M. Interchangeability and Intermixability of Parts

Interchangeability - Refer to Para. 2.C.

Intermixability - Not changed.

2. Material Information

A. Industry Support Information

Not applicable.

B. Material - Cost and Availability

You can get the procurable parts listed in Para. 2.C. from any Pratt & Whitney Canada

Parts Distribution Center.

The estimated total cost of new parts needed to replace old parts is $Quote (US, 2011).

The new parts are available.

C. Material Necessary for Each Engine

The quantity of materials listed in this section is on a per Engine basis.

New P/N Keyword Old P/N Qty

Est. Unit

List Price

($US,

2011)

Instructions

Disposition

3109595-01 Ring Assembly,

Containmnet, Power

Turbine

3022339 1 (A)(B)

3109594-01 Ê Liner, Reinforcement 1 Quote (C)

PRATT & WHITNEY CANADA

ALERT SERVICE BULLETIN

P&WC S.B. No. A1427R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator

Feb 03/1988 The export control classification with respect to this document is contained on the back of the locator. PT6A-72-A1427

Revision No. 3: Jan 27/2012 Page 3 of 7

TURBOPROP ENGINE

POWER TURBINE CONTAINMENT RING MODIFICATION OF
New P/N Keyword Old P/N Qty

Est. Unit

List Price

($US,

2011)

Instructions

Disposition

(A) ONE WAY INTERCHANGEABLE - (ATA 200 Explanation Code 01):

The old part can only replace the old part; the new part can replace the old and the new

part.

(B) To get the new part it is possible to make a modification to the old part, or you can get the

new part from any Pratt & Whitney Canada Distribution Center.

(C) NOT INTERCHANGEABLE - (ATA 200 Explanation Code 03):

The old part must replace the old part; the new part must replace new part.

D. Reidentified Parts

The following list of parts can be reworked:

OLD P/N NEW P/N

3022339 3109595-01

E. Tooling - Price and Availability

Not applicable.

3. Accomplishment Instructions

A. At engine disassembly, remove from engine existing power turbine containment ring

P/N 3022339 in accordance with overhaul manual instructions.

B. Existing serviceable containment ring P/N 3022339 can be reworked and reidentified as

follows:

(1) Install reinforcement liner P/N 3109594-01 into the power turbine containment ring

(Ref. Fig. 1).

(2) Using a suitable clamping device, clamp at least twelve positions to minimize gap

between liner outside diameter and ring inside diameter during welding.

(3) Weld liner using filler wire AMS 5679 or 5675 and T.I.G. method of welding (Ref.

Fig. 1, View B B).

(4) For containment ring P/N 3022339 prior change letter H, modify as follows (Ref.

Fig. 2)

(a) Machine scallops (5)

(b) Break all sharp edges.

PRATT & WHITNEY CANADA

ALERT SERVICE BULLETIN

P&WC S.B. No. A1427R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator

Feb 03/1988 The export control classification with respect to this document is contained on the back of the locator. PT6A-72-A1427

Revision No. 3: Jan 27/2012 Page 4 of 7

TURBOPROP ENGINE

POWER TURBINE CONTAINMENT RING MODIFICATION OF
0.050

NO WELD

0.030 A

0.700 MAX.

OVERLAPPING

P/N 3022339 (PRE−SB)

P/N 3109595 (POST−SB)

SLEEVE

P/N 3109594−01

0.070 

MIN.

0.125

MIN.

SECTION A−A

VIEW B

B

A

A

D

C

0.050

NO WELD

(POST−SB)

C193066

Rework and reidentification of Power Turbine Containment Ring

Figure 1

PRATT & WHITNEY CANADA

ALERT SERVICE BULLETIN

P&WC S.B. No. A1427R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator

Feb 03/1988 The export control classification with respect to this document is contained on the back of the locator. PT6A-72-A1427

Revision No. 3: Jan 27/2012 Page 5 of 7

TURBOPROP ENGINE

POWER TURBINE CONTAINMENT RING MODIFICATION OF
0.117

OFFSET HOLE

0.053

MIN.

30

35 47

10.480

10.460

DIA

0.270

0.250

0.160

0.140 0.405

0.375R 8

70 45

0.160

0.140

4 PLACES 0.405

0.375R

4 PLACES

°

° °

°

° °

− −D

C193067

Rework and reidentification of Power Turbine Containment Ring

Figure 2

PRATT & WHITNEY CANADA

ALERT SERVICE BULLETIN

P&WC S.B. No. A1427R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator

Feb 03/1988 The export control classification with respect to this document is contained on the back of the locator. PT6A-72-A1427

Revision No. 3: Jan 27/2012 Page 6 of 7

TURBOPROP ENGINE

POWER TURBINE CONTAINMENT RING MODIFICATION OF
3. Accomplishment Instructions (Cont’d)

(5) Fluorescent penetrant inspect weld per SPOP 62.

WARNING: USE EYE PROTECTION WHEN YOU WRITE WITH THE VIBRATION

PEENING PROCEDURE.

(6) Put a line across the old part number. Use the vibration peening procedure, 0.003

to 0.006 in. (0.08-0.15 mm) deep, and write the new part number (Ref. Para. 2D) in

the same area.

C. Existing serviceable containment ring P/N 3109595-01 (Previously modified by SB 1427)

not incorporating scallops (5) are to be modified as follows (Ref. Fig. 2)

(1) Machine scallops (5)

(2) Break all sharp edges.

(3) Fluorescent penetrant inspect per SPOP 62.

D. At engine assembly, install on engine new or reworked power turbine containment ring

assembly P/N 3109595-01 in accordance with overhaul manual instructions

E. Write accomplishment of P&WC S.B. No. 1427 in the applicable engine module log

book.

4. Appendix

Not applicable.

PRATT & WHITNEY CANADA

ALERT SERVICE BULLETIN

P&WC S.B. No. A1427R3

P&WC Proprietary Information. Subject to the restrictions on the back of the locator

Feb 03/1988 The export control classification with respect to this document is contained on the back of the locator. PT6A-72-A1427

Revision No. 3: Jan 27/2012 Page 7 of 7

TURBOPROP ENGINE

POWER TURBINE CONTAINMENT RING MODIFICATION OF