SERVICE BULLETIN

SERVICE BULLETIN F50-61-A165

TRANSMITTAL LETTER FOR REVISION NO.2

Dated Jul 28/15

1. REASON

A. Marking of conversion scheme number 650510484 at 3. A. (7) revised to include procedures for unpainted

and painted hubs.

2. ACTION

A. Remove and destroy existing pages 1, 3 and 4 of the service bulletin and replace with revised pages 1, 3

and 4 dated Jul 28/15.

Dowty Propellers

Anson Business Park, Cheltenham Road East, Gloucester, GL2 9QN ENGLAND

Telephone: 01452 716000 Facsimile: 01452 716001
Page 1 of 5

CAGE CODE: U7387

For Europe, Africa, India and

Middle East contact:

Dowty Propellers

Anson Business Park

Cheltenham Road East,

Gloucester, GL2 9QN, United Kingdom

T: + 44 (0)1452 716000

F: + 44 (0)1452 716001

For Asia, Australasia and the Pacific

contact:

Dowty Propellers

Anson Business Park

Cheltenham Road East,

Gloucester, GL2 9QN, United Kingdom

T: + 44 (0)1452 716000

F: + 44 (0)1452 716001

For the Americas

contact:

Dowty Propellers

114 Powers Court

Sterling, VA 20166

United States of America

T: + 1 (703) 421 4434

F: + 1 (703) 450 0087

GEK 119812

Copyright (2012), GE Aviation Systems Ltd., U.K

The information contained in this document is GE Aviation Systems Ltd proprietary information and is disclosed in confidence. It is the

property of GE Aviation Systems Ltd and shall not be used, disclosed to others or reproduced without the express written consent of GE

Aviation Systems Ltd, including, but without limitation, it is not to be used in the creation, manufacture, development, or derivation of any

repairs, modifications, spare parts, designs, or configuration changes or to obtain FAA, CAA, EASA, or any other government or regulatory

approval to do so. If consent is given for reproduction in whole or in part, this notice and the notice set forth on each page of this document

shall appear in any such reproduction in whole or in part. The information in this document may also be controlled by U.K. export laws.

Unauthorized export or re-export is prohibited.

All technical documentation and information contained herein, with respect to assembly and disassembly, cleaning, inspection methods

and limits, repair methods and limits, operational limits, life limits and the like, have been developed and approved for use with this

equipment and parts that have been manufactured and/or approved by GE and that have been maintained in accordance with GE 

technical documentation and recommendations. GE has no contractual or legal obligation for, nor knowlege of, non-GE-approved

parts and repairs. Accordingly, this document is not intended to apply to non-GE-approved parts and repairs.

ALERT

 Manual Ref: 61-10-34

SERVICE BULLETIN

PROPELLER - REAR HALF HUB DOWEL HOLE CRACKS

1. Planning Information

WARNING: FAILURE TO IMPLEMENT ANY INSTRUCTION GIVEN HERE, AS AMENDED FROM TIME

TO TIME BY DOWTY PROPELLERS, MAY ENDANGER HEALTH AND SAFETY.

A. Effectivity

Aircraft affected : Fokker F27 Mk 050, F27 Mk 0502 and F27 Mk 0604

Unit affected : Propeller

Type No. : (c)R352/6-123-F/1, (c)R352/6-123-F/2, (c)R410/6-123-F/35

Part No. : 660715001, 660715004 and 660715005

Hub Part No. 660715201, 660715255, 660720217,660720241, 660720252, 660720260,

660720288. All other hub part numbers are not affected by this service bulletin.

Serial Nos. : All

B. Concurrent requirements

(1) None.

Non Mod.

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Jul 28/15 (Revision 2)
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Use o r disclosure of data co ntain ed on this sheet is su bject to the rest rictions on the cover or first page

ALERT

C. Reason

(1) Cracks have been found around the hub location dowel holes in the face of the rear half hub of the

propeller. These cracks will reduce the service life of the hub assembly.

(2) The installation of liners in the hub location dowel holes will reduce the occurrence of cracks and

extend the service life of the hub assembly.

D. Description

(1) This service bulletin gives the procedure for the installation of liners in the hub location dowel holes

in the face of the rear half hub.

E. Compliance - ALERT

(1) For any hub with a part number shown in para 1.A. that has not been repaired to CMM 61-10-34,

Repair No. 53. Install the liners into the hub location dowel holes at the next shop visit when the

propeller is sent for repair or overhaul. Refer to the accomplishment instructions para 3.

(2) For any hub that has been inspected and found to have been repaired to CMM 61-10-34, Repair

No. 53. Refer to para 3.B. only.

F. Approval

(1) This service bulletin was approved and classified as ALERT. The technical content of this service

bulletin, which affects airworthinesss, is approved under the authority of Design Organisation

Approval No. EASA.21J.008.

G. Manpower

(1) This service bulletin will take approximately 5.0 man-hours to incorporate at repair or overhaul.

H. Weight and Balance

(1) None.

I. Electrical Load Data

(1) None.

J. Software Accomplishment Summary

(1) None.

K. References

(1) Dowty Propellers Component Maintenance Manual 61-10-34.

(2) Dowty Propellers Standard Practices Manual 60-00-00.

L. Other Publications Affected

(1) None.

M. Interchangeability or Intermixability of Parts

(1) None.

Nov 19/12 F50-61-A165

May 12/15 (Revision 1)
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Use o r disclosure of data co ntain ed on this sheet is su bject to the rest rictions on the cover or first page

ALERT

2. Material Information

A. Material-Price and Availability

(1) The items necessary to accomplish this Service Bulletin are given in para 2. B. 

(2) Make an order for the items to the address that follows:

Aviall Services, Inc.

PO Box 619048

DFW Airport

Dallas TX75261

USA

(3) Ask Aviall for the price and supply date.

B. Material Necessary

The items necessary to accomplish this Service Bulletin are:

New Qty for

Part No. Each Unit Name

(1) 660712687 2 Liner 

(2) P999230 A/R Sealant (PR1440B-B1/2, PS5020-3)

C. Reidentified Parts

(1) None.

D. Tooling

(1) None.

3. Accomplishment Instructions

The figure/item numbers in parentheses are those used in the illustrated parts list of the Component

Maintenance Manual.

A. Procedure (Refer to Figure 1)

(1) Machine the dowel holes and chamfers as shown.

(2) Flaw detect the machined areas: refer to NDT 8DAP.

(3) Locally apply protective treatment to the machined surfaces in accordance with PS5118 or,

PS5114.

(4) Refer to PS5020-3. Apply a bead of PR1440B-B1/2 (P999230) sealant to the bottom of the fine limit

bore in the dowel holes in area Y. This will hold the liners.

(5) Assemble the liners 660712687 to the dowel holes as shown. Do a check to make sure the internal

diameter of the liners is as shown.

(6) Repair any damaged paint: refer to PS51003-1.

(7) Write the Dowty Propellers conversion scheme number 650510484 adjacent to the existing part

number as follows:

(a) For unpainted hubs, in accordance with PS5405-3.

(b) For painted hubs, in accordance with PS5405-1.

(8) Examine the part to ensure that the conversion scheme, number 650510484 procedure, has been

correctly performed.

Nov 19/12 F50-61-A165

Jul 28/15 (Revision 2)
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ALERT

B. Records

(1) When the instructions of this service bulletin have been completed, write the Service Bulletin No.

F50-61-A165 in the propeller log book and on the hub log card.

(2) For any hub that has been repaired to CMM 61-10-34, Repair No. 53:

(a) Write the conversion scheme number 650510484 adjacent to the existing part number at the

next shop visit. Refer to PS5405-3.

(b) Write the service bulletin number F50-61-A165 in the propeller log book and on the hub log

card.

Nov 19/12 F50-61-A165

Jul 28/15 (Revision 2)
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GE Aviation Systems Ltd Proprietary Information 

Use o r disclosure of data co ntain ed on this sheet is su bject to the rest rictions on the cover or first page

ALERT

Conversion of Hub Assembly

Figure 1

F506753

17,0 mm (0.669 in) DIA. (REF.)

22,5 mm (0.88 in) MAXIMUM

TO DRILL POINT (REF.)

18,30 to 18,55 mm

(0.720 to 0.730 in)

21,0 mm (0.826 in) (REF.)

18,75 to 19,0 mm DIA.

(0.738 to 0.748 in)

CHAMFER

21,97 to 22.22 mm DIA.

(0.864 to 0.874 in)

17,467 to 17.478 mm DIA.

(0.687 to 0.688 in)

0,04 mm DIA.

(0.001in) A

0,25 to 0.38 mm RAD

(0.009 to 0.014 in)

45o

2,0 mm (0.078) RAD.

1,75 to 1,00 mm RAD.

 (0..03 to 0.04 in)

(REF.)

0,38 to 0,643 mm

(0.015 to 0.025 in)

DETAIL Z

DETAIL Z

15,95 mm (0.628 in) DIA.

 MINIMUM LINER BORE

AFTER LINER ASSEMBLY

660712687 (2-0FF) LINER

FITTED FLUSH WITH CHAMFER

AT MOUTH OF BORE

A

171,45 DIA.

(6.75 in)

Y

0,1

(4)

Nov 19/12 F50-61-A165

May 12/15 (Revision 1)