## Service Bulletin Fokker 50/60

Copyright All rights reserved by Fokker Services B.V. (The Netherlands). This document has been supplied by Fokker Services B.V . to its customers on a confidential basis subject to the provisions of an agreement. Reproduction or disclosure to third parties of this document or any part thereof, or the use of any information contained there in for purposes other than explicitly allowed by the aforesaid agreement, is not permitted except with the prior written permission of Fokker Services B.V.

May 20/10 SBF50-28-028 Revision 1, Sep 15/10 Page 1 1. Planning Information

A. Effectivity

(1) F27 Mark 050, 0502 and 0604 aircraft serial number(s):
20133 thru 20335, if no inboard fuel tanks are installed.

B. Concurrent Requirements

(1) Not applicable.

C. Reason

(1) An operator reported that in the LH nacelle the upper rod-end of the spring box of the main landing gear (MLG) actuator had touched a fuel pipe and that in the RH nacelle the MLG lock link (at the ground lock pin side) had touched another fuel pipe. For that reason SBF50-28-011 was issued in 1990 to introduce an inspection in each nacelle for a minimum clearance of 1.5 mm between the affected MLG parts and the fuel pipes. SBF50-28-011 also required the installation of new fuel pipe part numbers if less than 1.5 mm clearance was found.

Page 1 2 3 4 5 6 7 8 9

Revision 1 1 1 1 1 1 1 1 1 This Service Bulletin cancels Service Bulletin SBF50-28-011 (Part 1 )

FUEL

“This Service Bulletin is associated with the Fuel Tank Safety Program”

Distribution - A One-Time Inspection of the Configuration and Clearances of Fuel Pipes in the Nacelles

## Service Bulletin Fokker 50/60

Copyright All rights reserved by Fokker Services B.V. (The Netherlands). This document has been supplied by Fokker Services B.V . to its customers on a confidential basis subject to the provisions of an agreement. Reproduction or disclosure to third parties of this document or any part thereof, or the use of any information contained there in for purposes other than explicitly allowed by the aforesaid agreement, is not permitted except with the prior written permission of Fokker Services B.V.

SBF50-28-028 May 20/10 Page 2 Revision 1, Sep 15/10 (2) The (subsequent) design review of the F27 Mk 050, 0502 and 0604 fuel system in accordance with the guidelines related to FAA SFAR 88 and JAA INT/POL/25/12 revealed that an unsafe condition can develop if the clearance between the upper rod-end of the MLG spring box and the fuel pipe and/or the clearance between the MLG lock link at the ground lock pin side and the other fuel pipe is less than 3.0 mm. Insufficient clearance may result in chafing with possibly subsequent fuel leakage. With additional factors, this may result in an unsafe condition.

(3) This Service Bulletin introduces a one-time inspection to verify the part numbers of the two fuel pipes in each nacelle. When the fuel pipe part numbers specified in this Service Bulletin are installed, no further action is required because they ensure a minimum clearance of 3.0 mm with the MLG parts. However if other fuel pipe part numbers are installed, a check for a minimum clearance of 3.0 mm must be performed. If that clearance is less than 3 .0 mm, SBF50-28-031 (introducing fuel pipe part numbers which ensure 3.0 mm clearance) must be accomplished. If the clearance is more than 3.0 mm, repeat inspections must be performed (ref fuel ALI in paragraph 1.L.(1)(c) of this Service Bulletin) and the accomplishment of SBF50-28- 031 is optional (removing the fuel ALI requirement).

Reason for Revision

(1) This revision is made to: - Change the aircraft effectivity in the Planning Information 1.A.(1) - Delete the NOTE below the CDCCL item for the post SBF50-28-031 configuration in Publications Affected 1.L.(1) (c) - Change header of Service Bulletin - Change approval statement in paragraph 1.F.(1).(“Aproval”) - Attach Revision 1 of MCNM F50-071 to the Service Bulletin.

D. Description

(1) This Service Bulletin is divided into two parts and tells you how to:

- Part 1 : Check the Part Numbers of the Fuel Pipes in each Nacelle.

- Part 2 : Check the Clearance between MLG Parts and Fuel Pipes in each Nacelle.

E. Compliance

(1) Recommended.

Fokker Services recommends the accomplishment of this Service Bulletin (part 1 and, if applicable part 2) within 6 months after the date of issue of this Service Bulletin.

## Service Bulletin Fokker 50/60

Copyright All rights reserved by Fokker Services B.V. (The Netherlands). This document has been supplied by Fokker Services B.V . to its customers on a confidential basis subject to the provisions of an agreement. Reproduction or disclosure to third parties of this document or any part thereof, or the use of any information contained there in for purposes other than explicitly allowed by the aforesaid agreement, is not permitted except with the prior written permission of Fokker Services B.V.

May 20/10 SBF50-28-028 Revision 1, Sep 15/10 Page 3 NOTE : It is expected that EASA will issue an Airworthiness Directive (AD) with respect to this subject with the same compliance terms. Refer to the EASA website for the publication of a Proposed Airworthiness Directive for comments.

F. Approval

(1) The technical content of this document is approved under the authority of DOA nr. EASA.21J.059.

G. Manpower

(1) Approximately 8,0 man-hours are necessary to do Part 1 or Part 2 of this Service Bulletin on one aircraft. (16,0 man-hours for both part 1 and part 2)

This table of manpower will help you to schedule and do this Service Bulletin:

Instructions Men Man-hours Elapsed time (hours)
Removal - - - Modification Inspection 2 8,0 4,0

Installation - - - Testing - - -

Total 8,0 4,0

NOTE : This estimate does not include the time necessary for the paint to dry and/or the sealant to cure.

(2) The estimated hours are for direct labor done by experienced personnel. They are calculated based on the conditions given in SBF50-00-001 (Service Bulletin Introduction, section 2.C., "Manpower").

H. Weight and Balance

(1) Weight change: None Index change: None.

I. Electrical Load Data

(1) Not affected.

J. Software Accomplishment Instructions

(1) Not applicable.

## Service Bulletin Fokker 50/60

Copyright All rights reserved by Fokker Services B.V. (The Netherlands). This document has been supplied by Fokker Services B.V . to its customers on a confidential basis subject to the provisions of an agreement. Reproduction or disclosure to third parties of this document or any part thereof, or the use of any information contained there in for purposes other than explicitly allowed by the aforesaid agreement, is not permitted except with the prior written permission of Fokker Services B.V.

SBF50-28-028 May 20/10 Page 4 Revision 1, Sep 15/10 K. References

(1) Fokker 50 Aircraft Maintenance Manual (AMM). Fokker Consumable Material List (CML). Fokker 50 Service Bulletin (SB): - SBF50-28-011 - SBF50-28-031.

L. Publications Affected

(1) This SB affects the publications listed below:

(a) Maintenance Documentation

- Fokker 50/60 Aircraft Maintenance Manual (AMM) - chapter 28-16 - chapter 32-30

NOTE : See attached Manual Change Notification MCNM F50-071 Revision 1.

(b) Maintenance Programs

- Fokker 50/60 Maintenance Review Board (MRB) - Fokker 50/60 Maintenance Planning Document (MPD) - Fokker 50/60 Customized Maintenance Program (CMP).

(c) Special Instructions for Continued Airworthiness (ICA)

The effect of this Service Bulletin on the special ICA is as follows:

YES NO - Electrical Wiring Interconnection system (EWIS) X - Fuel Tank Safety (FTS) X - - Damage Tolerance of Fatigue Critical Structure X

NOTE : If “YES”, when not already incorporated, the changed ICA will be incorporated in the MRB document within one calendar year from the date of issue of this Service Bulletin. Until then, the Fuel ALI and CDCCL actions as specified below shall be followed.

For F27 Mk050, 0502, 0604 aircraft in the pre SBF50-28-031 configuration :

Fuel ALI : A detailed inspection shall be performed on clearances of the fuel pipes in the LH and RH nacelle. The clearance shall be a minimum of 3.0 mm.

The inspection interval is 4800 FH and the first repeat inspection must be performed not later than 4800 FH after part 2 of this Service Bulletin was performed.

## Service Bulletin Fokker 50/60

Copyright All rights reserved by Fokker Services B.V. (The Netherlands). This document has been supplied by Fokker Services B.V . to its customers on a confidential basis subject to the provisions of an agreement. Reproduction or disclosure to third parties of this document or any part thereof, or the use of any information contained there in for purposes other than explicitly allowed by the aforesaid agreement, is not permitted except with the prior written permission of Fokker Services B.V.

May 20/10 SBF50-28-028 Revision 1,Sep 15/10 Page 5 NOTE : The inspection must be performed in accordance with the instructions in the new task 28-16-00-200-816-A introduced with attached Revision 1 of MCNM F50-071.

CDCCL : In case of the replacement or removal / installation of the fuel pipes or removal / installation of the MLG gear upper member, outer cylinder, drag stay or lock link in the LH or RH nacelle, it shall be assured that the minimum clearance is 3.0 mm.

NOTE : The verification shall be performed in accordance with the instructions in the AMM task 32-30-00-710-815-A, changed in accordance with the change instructions for pre SBF50-28-031 aircraft in the attached Revision 1 of MCNM F50-071.

For F27 Mk050, 0502, 0604 aircraft in the post SBF50-28-031 configuration

CDCCL : In case of replacement or removal / installation of the fuel pipes in the LH and RH nacelle, it shall be assured that the fuel pipes and associated brackets and clamps remain in the post SBF50-28-031 configuration.

(d) Operational Documentation

Not affected.

(2) For incorporation of this Service Bulletin in your documentation refer to SBF50-00-001 (Service Bulletin Introduction, section 4 "Incorporation of Service Bulletins in Documentation of Fokker Services").

M. Interchangeability or Intermixability of Parts

(1) Not applicable.

## Service Bulletin Fokker 50/60

Copyright All rights reserved by Fokker Services B.V. (The Netherlands). This document has been supplied by Fokker Services B.V . to its customers on a confidential basis subject to the provisions of an agreement. Reproduction or disclosure to third parties of this document or any part thereof, or the use of any information contained there in for purposes other than explicitly allowed by the aforesaid agreement, is not permitted except with the prior written permission of Fokker Services B.V.

SBF50-28-028 May 20/10 Page 6 Revision 1, Sep 15/10 2. Material Information

A. Material – Price and Availability

(1) The materials are local source items.

B. Material Required

(1) These parts, which are necessary to complete this Service Bulletin on 1 aircraft, are not part of the mod kit.

New Part Number Qty Keyword Info Old Part Number Instructions/ Disposition

- * Plasticine - - Local source

NOTE:* Use as much as necessary.

(2) These mod kit parts are necessary to do this Service Bulletin on 1 aircraft.

(a) Not applicable.

C. Tooling – Price and Availability

(1) Not applicable.

D. Drawings Required

(1) Not applicable.

## Service Bulletin Fokker 50/60

Copyright All rights reserved by Fokker Services B.V. (The Netherlands). This document has been supplied by Fokker Services B.V . to its customers on a confidential basis subject to the provisions of an agreement. Reproduction or disclosure to third parties of this document or any part thereof, or the use of any information contained there in for purposes other than explicitly allowed by the aforesaid agreement, is not permitted except with the prior written permission of Fokker Services B.V.

May 20/10 SBF50-28-028 Revision 1, Sep 15/10 Page 7 3. Accomplishment Instructions

General

- These instructions are applicable to the LH and RH installation.

- Data for the RH installation is between parentheses.

- Refer to the CML for material numbers.

Part 1

A. Do a Configuration Check of the affected Fuel Pipes in each Nacelle.

Refer to figure 1.

(a) If all part numbers of the installed fuel pipes (2 in each nacelle) are mentioned in the list below, then state in the aircraft logbook that the aircraft is post SBF50-28- 031.

(b) If one or more part numbers of the installed fuel pipes ( 2 in each nacelle) are not mentioned in the list below, then perform part 2 of this Service Bulletin.

- WIF7039-413 (WIF7039-414) or F8423-112-407 (F8423-112-408)

- WIF7039-409 (WIF7039-411) or F8423-107-409 (F8423-107-411). Part 2

A. Do an Inspection to Check the Clearance between the MLG and the Fuel Pipes in each the Nacelle.

Refer to figure 1.

(1) Attach plasticine with a minimum thickness of 10 mm to the fuel pipes at the positions shown for the LH and RH Nacelles.

(2) Put the aircraft on jacks (Refer to the AMM, chapter 07-11-00)

(3) Do a retraction/extension test of the MLG (Refer to the AMM, chapter 32-30-00)

(4) Examine the plasticine for the imprint made by the MLG and carefully determine the clearance by measuring the shortest distance from each fuel pipe to the imprint of the MLG in the piece of plasticine.

(a) If, for all 4 fuel pipes, the measured clearance is more than 3.0 mm, then continue with step (5).

## Service Bulletin Fokker 50/60

Copyright All rights reserved by Fokker Services B.V. (The Netherlands). This document has been supplied by Fokker Services B.V . to its customers on a confidential basis subject to the provisions of an agreement. Reproduction or disclosure to third parties of this document or any part thereof, or the use of any information contained there in for purposes other than explicitly allowed by the aforesaid agreement, is not permitted except with the prior written permission of Fokker Services B.V.

SBF50-28-028 May 20/10 Page 8 Revision 1, Sep 15/10 (b) If, on one or more of the 4 fuel pipes, chafing marks are present on the fuel pipe or the measured clearance is less than 1.5 mm, Service Bulletin SBF50-28-031 shall be accomplished before further flight.

(c) If, on one or more of the 4 fuel pipes, the measured clearance is between 1.5 mm and 3.0 mm, Service Bulletin SBF50-28-031 shall be accomplished within 2 years after the issue date of this Service Bulletin SBF50-28-028.

(5) Remove the plasticine that you attached in step (1).

B. Remove the tools, materials and equipment from the work area. Make sure that work area is clean.

C. Lower the aircraft to the ground and remove the jacks (Refer to the AMM, chapter 07-11- 00).

D. State in your Aircraft Logbook that the aircraft is post SBF50-28-028 Part 1 and Part 2

.

## Service Bulletin Fokker 50/60

Copyright All rights reserved by Fokker Services B.V. (The Netherlands). This document has been supplied by Fokker Services B.V . to its customers on a confidential basis subject to the provisions of an agreement. Reproduction or disclosure to third parties of this document or any part thereof, or the use of any information contained there in for purposes other than explicitly allowed by the aforesaid agreement, is not permitted except with the prior written permission of Fokker Services B.V.

May 20/10 SBF50-28-028 Revision 1, Sep 15/10 Page 9 The General Arrangement of the Fuel Pipes

Figure 1

## Manual Change Notification – Maintenance Documentation Fokker 50/60

SEP 15/10 MCNM F50-071 REV 1 Page 1 of 4 

### MCNM-F50-071 REV 1

Subject : Fuel – Inspection of the Fuel Pipes in the Nacelle, and if necessary, the Installation of Four New Fuel Pipes.
Reason : This MCN is issued to provide you with the changes on the content(s) of the affected manual(s), due to the introduction of SBF50-28-028 and SBF50-28-031.

Reason for Revision : CDCCL affected sections in AMM Task 32-30-00-710-815 are not applicable to aircraft which are in the Post SBF50-28-031 configuration. In addition, a new AMM Task is introduced for replacement of the fuel-pipes that are in the Pre SBF50-28- 031 configuration.
Effectivity : Refer to SBF50-28-028 and SBF50-28-031.
Compliance : Once you have determined the applicability of this MCN for one or more of your aircraft, incorporate this information into the applicable manual(s).

Publications Affected : The Aircraft Maintenance Manual (AMM) The Illustrated Parts Catalogue (IPC).
Change Note : AMM
If your aircraft stays in the Pre SBF50-28-031 configuration, then update AMM Task 32-30-00-710-815-A, as follows:
- Add the text (CDCCL) in front of the title of the Task - Add the following Notes below the title of the Task:

- Add this new Subtask before Subtask 32-30-00-001-205-A00:

## Manual Change Notification – Maintenance Documentation Fokker 50/60

SEP 15/10 MCNM F50-071 REV 1 Page 2 of 4 - Add this new Subtask after Subtask 32-30-00-001-355-A00:

- Add a new Fig. 32-30-00-990-015-A00 at the end of the Task, as shown on Figure 1 of this MCN.

If your aircraft stays in the Pre SBF50-28-031 configuration, then add a new Task 28-16-00-200-816-A, and do as follows: - Use this title for the new Task:
Check of the Clearance between the Fuel Pipe Installation in the Nacelle and the

Main Landing Gear Installation

- Add this text below the title of the new Task:

This maintenance procedure affects Fuel Tank Safety. It is related to a fuel system ALI (Airworthiness Limitation Item). Strictly adhere to the contents of this task to make sure that unsafe conditions do not develop.
- Make a copy of all Subtasks given in the updated AMM Task 32-30-00-710- 815-A (including the change notes of this MCN) - Delete the copied Subtasks 32-30-00-001-275-A00 thru 32-30-00-001-305- A00 from the new Task - Re-identify all copied Subtasks, to comply with the identification of the new Task - At the end of the new Task, add a new Fig. 28-16-00-990-016-A00 as shown on Figure 1 of this MCN.

## Manual Change Notification – Maintenance Documentation Fokker 50/60

SEP 15/10 MCNM F50-071 REV 1 Page 3 of 4 If your aircraft stays in the Pre SBF50-28-031 configuration, then add a new Task 28-16-00-300-812-A, and do as follows: - Use this title for the new Task:

(CDCCL) Replacement of Transfer-lines in the Nacelle between STA 2574 and STA 4052

- Add this text below the title of the new Task:

NOTE: This Task gives an abbreviated procedure for replacement of the fuel pipes that are in the Pre SBF50-28-031 configuration.

- Use this procedure for the new Task:

WARNING: OBEY THE SAFETY PRECAUTIONS GIVEN IN 28-00-00-610-813. JET FUEL IS EXPLOSIVE AND POISONOUS.

A. Defuel the LH (RH) main tank (Refer to Task 12-11-01-650-813 for more data). B. Remove the access panel 925AZ (926AZ). C. Replace the fuel pipe(s) (Refer to IPC 28-16-04-01 for more details).

NOTE: Start of Fuel System CDCCL affected section.
D. Do a check of the clearance between the main landing gear and the fuel pipes (Refer to Task 32-70-00-710-815 for more data).

NOTE: End of Fuel System CDCCL affected section.

E. Refuel the LH (RH) main tank (Refer to Task 12-11-01-650-813 for more data). F. Examine the fuel pipe(s) that you installed, for leaks. G. Install the access panel 925AZ (926AZ).

IPC
If applicable, update the fuel pipe installation in IPC Figure 28-16-04-01, in accordance with SBF50-28-031.

NOTE : If you have a Documentation Revision Service (DRS) with Fokker Services, this information will be included into your manuals at the earliest opportunity.

NOTE : MCNM-F50-071 Revision 1 supersedes MCNM-F50-071, dated MAY 20/10. Text highlighted by a revision bar indicates: - A revision of the text introduced with the original issue of this MCN - An introduction of new changes. Text not highlighted by a revision bar was already included in the original issue of this MCN and is not revised. It is retained for clarity.

## Manual Change Notification – Maintenance Documentation Fokker 50/60

SEP 15/10 MCNM F50-071 REV 1 Page 4 of 4 Fuel Pipe Installation in Nacelle – Check Figure 1