# 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 th e 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 716001Page 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 System s Ltd proprietary information and is disclosed in confidence. I t is the property of GE Aviation Systems Ltd and shall not be used, discl osed to others or reproduced wi thout the express written consen t of GE Aviation Systems Ltd, including, but without limitation, it is not to be used in the creation, m anufacture, development, or der ivation of any repairs, modifications, spare parts, designs, or configuration chang es or to obtain FAA, CAA, EASA, or any other government or regulatory approval to do so. If consent is given for reproduction in whol e 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 in formation in this document may also be controlled by U.K. exp ort 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 w ith 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, MA Y 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)R 352/6-123-F/2, (c)R410/6-123-F/35 Part No. : 660715001, 660715004 and 660715005 Hub Part No. 660715201, 660715255, 660720 217,660720241, 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. Nov 19/12 

# F50-61-A165 Jul 28/15 (Revision 2)Page 2 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
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 hole s 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 in stallation 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 in to 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 ma n-hours to incorp orate 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)Page 3 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
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 pr ice 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 listof 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 conversi on scheme, number 650510484 procedure, has been correctly performed.

Nov 19/12 

# F50-61-A165 Jul 28/15 (Revision 2)Page 4 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
B. Records (1) When the instructions of this service bulletin have been completed, writ e 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)Page 5 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 RA D (0.009 to 0.014 in) 45 o 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)