Service Bulletin 

Fokker 70/100 

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 therein for purposes other than explicitly allowed by the aforesaid agreement, is not permitted 

except with the prior written permission of Fokker Services B.V. 

Apr 27/09 SBF100-27-092 

Page 1 

FLIGHT CONTROLS

Horizontal Stabilizer - Introduction of Bolts with increased corrosion protection in the Stabilizer 

 Control Unit Dog-Links 

1. Planning Information

A. Effectivity 

(1) F28 Mark 0100 aircraft serial numbers: 

11244 thru 11527. 

(2) Production version of this modification: Not applicable. 

B. Concurrent Requirements 

(1) Not applicable. 

Page 1 2 3 4 5 6 7 8 

Revision - - - - - - - - 
Service Bulletin 

Fokker 70/100 

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 therein for purposes other than explicitly allowed by the aforesaid agreement, is not permitted 

except with the prior written permission of Fokker Services B.V. 

SBF100-27-092 Apr 27/09 

Page 2 

C. Reason 

(1) Recently on two Fokker 100 a/c, during accomplishment of task 062307-00-01, 

surveillance inspection of vertical stabilizer, it was found that bolt pn 23233-1 that 

connects the Horizontal Stabilizer Control Unit (HSCU) actuator with the doglinks, 

was broken (one on the nut side & one on the head side). In both occasions, the bolt 

shaft was still present in the connection and therefore the horizontal stabilizer function 

was not affected. The failed bolts were replaced and as a precaution the other bolts 

were also replaced. Subsequently 7 more a/c of the same Operator were inspected 

without further findings. 

(2) The horizontal stabilizer is connected to the HSCU actuator via two doglinks. If one of 

the connections fails the complete stabilizer load can be taken by the remaining 

doglink. Failure of the connection may stay undetected until the next scheduled 

surveillance inspection. The interval of the task is 4000 FH. When the bolt fails at the 

nut-end then the remaining part of the bolt can not drop out of the connection due to 

the limited amount of space available between the bolt-head and the plate which is 

installed in between the two bolts. In this way the affected connection is still able to 

carry the system loads. If the head side of the bolt fails then in the end the bolt may 

drop out of the connection. 

(3) In January 1996 Fokker issued Service Bulletin SBF100-27-069 (Goodrich SB 

23100-27-19). This SB was issued to introduce an inspection of the same bolts for 

cracks. Additionally the same SB introduced a lower torque for these bolts. Reason 

for the mandatory SB with a compliance of 3 months for lowering of the torque and 9 

months for the inspection, was the outcome of the examination of a failed bolt. The 

examination revealed that the bolt broke due to stress corrosion. The stress corrosion 

was attributed to a too high bolt torque. Since issuance of SBF100-27-069, four bolt 

failures are known to FS. In three of these events the bolt failed at the head side. 

(4) Investigation of two of the recently failed bolts showed that the terminating action as 

given in SBF100-27-069 was apparently not fully effective. Therefore, 

SBF100-27-091 was issued in August 2007 to safeguard fleet airworthiness for the 

short term. As a result of the accomplishment of SBF100-27-091 over 50 bolts were 

replaced. To ensure the integrity on the long term Goodrich introduced a bolt with an 

improved corrosion protection i.e. pn 23233-3 with CSB 23100-27-29. After the 

introduction of the improved bolt, the tie-wrap that was introduced as a temporary 

measure with SBF100-27-091 is deleted. 

NOTE: This SB is a cover for CSB 23100-27-29. 
Service Bulletin 

Fokker 70/100 

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 therein for purposes other than explicitly allowed by the aforesaid agreement, is not permitted 

except with the prior written permission of Fokker Services B.V. 

Apr 27/09 SBF100-27-092 

Page 3 

D. Description 

(1) This Service Bulletin tells you how to: 

- Remove the tie-wrap and the lower bolts of the HSCU. 

- Install the improved bolts in the HSCU. 

E. Compliance 

(1) Recommended 

Fokker Services recommends the accomplishment of this Service Bulletin within 30 

months after the issue date of this Service Bulletin. 

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 by EASA or under the authority of 

DOA nr. EASA.21J.059. 

G. Manpower 

(1) Approximately 7 man-hours are necessary to do this Service Bulletin on one aircraft. 

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 3,0 1,5 

Installation 2 3,0 1,5 

Testing 2 1,0 0,5 

Total 7,0 3,5 

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 SBF100-00-001 (Service Bulletin 

Introduction, section 2.C., "Manpower"). 

H. Weight and Balance 
Service Bulletin 

Fokker 70/100 

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 therein for purposes other than explicitly allowed by the aforesaid agreement, is not permitted 

except with the prior written permission of Fokker Services B.V. 

SBF100-27-092 Apr 27/09 

Page 4 

(1) Weight change: None 

Index change: None. 

I. Electrical Load Data 

(1) Not affected. 

J. Software Accomplishment Instructions 

(1) Not applicable. 

K. References 

(1) Fokker 100 Aircraft Maintenance Manual (AMM) 

Fokker Consumable Material List (CML) 

Fokker 100 Service Bulletin (SB): 

 - SBF100-27-037 

 - SBF100-27-069 

 - SBF100-27-091 

Fokker internal reference(s): 

 - ECR 15583 

Goodrich CSB 23100-27-29. 

L. Publications Affected 

(1) This SB affects the publications listed below: 

(a) Maintenance Documentation

-Fokker 100 Illustrated Parts Catalog (IPC) - chapter 27-42 

NOTE: See attached Manual Change Notification MCNM F100-137. 

(b) Maintenance Programs

Not affected. 

(c) Special Instructions for Continued Airworthiness (ICA)

This Service Bulletin requires a revision to the Instructions for Continued 

Airworthiness (ICA) for: 

 YES NO 

- Electrical Wiring Interconnection System (EWIS) - X 

- Fuel Tank Safety (FTS) - X 

- Damage Tolerance of Fatigue Critical Structure - X 

(d) Operational Documentation
Service Bulletin 

Fokker 70/100 

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 therein for purposes other than explicitly allowed by the aforesaid agreement, is not permitted 

except with the prior written permission of Fokker Services B.V. 

Apr 27/09 SBF100-27-092 

Page 5 

Not affected. 

(2) For incorporation of this Service Bulletin in your documentation refer to 

SBF100-00-001 (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 70/100 

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 therein for purposes other than explicitly allowed by the aforesaid agreement, is not permitted 

except with the prior written permission of Fokker Services B.V. 

SBF100-27-092 Apr 27/09 

Page 6 

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

23233-3 2 Bolt 23233-1 New 

F0N2-2210-10 AR Nut F0N2-2210-10 Local source 

Mastinox 6856H * Jointing 

Compound 

Fk05-003 

** 

 Local source 

Mastinox 6856K * Jointing 

Compound 

Fk05-010A

** 

 Local source 

MS24665-155 AR Cotter Pin MS24665-155 Local source 

MS24665-374 AR Cotter Pin MS24665-374 Local source 

 2 Tie-wrap MS3367-2-9 Discard 

NOTES: * Use as much as necessary 

** Refer to the CML for material numbers. 

(2) These 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 70/100 

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 therein for purposes other than explicitly allowed by the aforesaid agreement, is not permitted 

except with the prior written permission of Fokker Services B.V. 

Apr 27/09 SBF100-27-092 

Page 7 

3. Accomplishment Instructions

General 

- Refer to the CML for material numbers. 

- For removal and installation of the HSCU bolts refer to AMM 27-42-01-000-814 & 

 AMM 27-42-01-400-814. 

A. Modify the HSCU. 

Ref. figure 1. 

(1) Removal of bolts and tie-wraps. 

Remove and discard: 

- 2 Tie-wrap MS3367-2-9 Discard 

- 2 Bolt 23233-1 Discard 

(2) Install the improved bolts. 

Use: 

- 2 Bolt 23233-3 New 

- AR Jointing Compound Mastinox 6856H or 

Mastinox 6856K 

Fk05-003 

Fk05-010A 

- AR Cotter Pin MS24665-155 

- AR Cotter Pin MS24665-374 

B. Do a test of the top anti-collision light. 

Action Result

(1) On the overhead panel, on the 

EXT LIGHTS panel, push the 

BEACON pushswitch 

(a) 

(b) 

The BEACON pushswitch OFF 

legend goes off. 

The top anti-collision light 

starts to flash. 

(2) On the overhead panel, on the 

EXT LIGHTS panel, push the 

BEACON pushswitch. 

(a) 

(b) 

The BEACON pushswitch OFF 

legend comes on. 

The top anti-collision light goes 

off. 

C. Remove all tools, material and equipment from the working area. Make sure the working 

area is clean. 

D. Move the Horizontal Stabilizer through its complete range of travel and make sure that no 

interferences are present. 
Service Bulletin 

Fokker 70/100 

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 therein for purposes other than explicitly allowed by the aforesaid agreement, is not permitted 

except with the prior written permission of Fokker Services B.V. 

SBF100-27-092 Apr 27/09 

Page 8 

Figure 1 – HSCU Bolt Installation 

*

*

Modify the HSCU as follows: 

Ref. AMM 27-42-01-000-814 & 

AMM 27-42-01-400-814. 

- Cut and discard the tie-wraps. 

- Remove and discard bolts* pn 

 23233-1. 

- Install bolt* pn 23233-3. 
Manual Change Notification – Maintenance Documentation 

Fokker 70/100 

APR 17/09 MCNM F100-137

Page 1 of 1 

MCNM-F100-137 

Subject : Flight Controls –Horizontal Stabilizer – Introduction of Bolts with increased corrosion 

protection in the Stabilizer Control Unit Dog-Link. 

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 SBF100-27-092. 

Effectivity : Refer to SBF100-27-092. 

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 Illustrated Parts Catalogue (IPC). 

Change Note : IPC

 

 Update IPC Figure 27-42-01-01, as folllows: 

- Change the partnumber of the Bolt (Fig. item 190) to 23233-3 

- In the nomenclature of Fig. item 170 A thru 170 G (as applicable), add the text 

“SB27-29”. 

NOTE: If you have a Document Revision Service (DRS) with Fokker Services, this MCN 

will be included into your IPC, at the earliest opportunity.