## MARSHALL AEROSPACE AND DEFENCE GROUP THE AIRPORT, CAMBRIDGE, ENGLAND 

### SERVICE BULLETIN

Letter of Transmittall Page 1 of 1 MARSHALL AEROSPACE AND DEFENCE GROUP SERVICE BULLETIN SBM 200 MARSHALL AEROSPACE AND DEFENCE GROUP BRAKE MASTER CYLINDER PIVOT PIN EXAMINATION © 2015 Marshall Aerospace and Defence Group

THE INFORMATION CONTAINED IN THIS DOCUMENT CONTAINS PROPRIETARY DATA WHICH IS THE PROPERTY OF MARSHALL AEROSPACE AND DEFENCE GROUP AND IS DISCLOSED IN CONFIDENCE. THE DATA OR DOCUMENT SHALL NOT BE USED, DISCLOSED TO OTHERS OR REPRODUCED WITHOUT EXPRESS WRITTEN PERMISSION OF MARSHALL AEROSPACE AND DEFENCE GROUP. IF CONSENT IS GIVEN, THIS PROPRIETARY DATA NOTIFICATION SHALL APPEAR IN ANY REPRODUCTION, WHETHER IN WHOLE OR IN PART. Issued By Marshall Aerospace and Defence Group The Airport, Cambridge, CB5 8RX

LETTER OF TRANSMITTAL

Dated April 2015

This page transmits Initial Issue of Service Bulletin SBM 200

RECORD OF REVISIONS Revision No. Date Reason for Change 0 Initial Issue 1 April 2015 Amendment to Compliance - Accomplishment Timescales.

### MARSHALL AEROSPACE AND DEFENCE GROUP SERVICE BULLETIN



# SBM 200 Apr 15 (Rev 1) Page 1 of 8 BRAKE MASTER CYLINDER PIVOT PIN EXAMINATION 1. PLANNING INFORMA TION A. EFFECTIVITY Slingsby T67 Firefly T67B, T67C Series, T67M, T67M Mkll, T67M200, T67M260. B. CONCURRENT REQUIREMENTS None C. REASON A case has been reported of the failure of a brake master cylinder pivot pin part number T67M-45- 539 (Figure 1). Two of these pivot pins are fitted per aircraft, one to the #1 pedal assembly and one to the #4 pedal assembly. The operator reported hearing a breaking noise from the rudder pedal area during taxying. An investigation was carried out and it was discovered that the brake master cylinder pivot pin had broken on the #4 pedal assembly. The pin was broken between the threaded section and the larger central barrel (Figure 2). The surface of the broken material was found to be dull, indicating a possible fatigue related fracture. Unrelated to the pivot pin failure instances of dimensional differences to the brake master cylinder pivot pin design have been discovered (Figure 3). D. DESCRIPTION This Service Bulletin (SB) details the examination for damage and dimensional inconsistencies to the brake master cylinder pivot pin. E. COMPLIANCE (1) Classification Essential (2) Accomplishment Timescales Before next flight, unless SBM-200 Revision 0 has been carried out. Thereafter at each annual inspection in conjunction with SB187 or SB188 as applicable. F. APPROVAL Marshall Aerospace and Defence Group EASA Design Organization Approval No EASA.21J.181.

### MARSHALL AEROSPACE AND DEFENCE GROUP SERVICE BULLETIN



# SBM 200 Mar 15 Page 2 of 8 G. MANPOWER One person – approximate man-hours as follows:

H. WEIGHT AND BALANCE No change. I. ELECTRICAL LOAD DATA No change. J. SOFTWARE SUMMARY Not Applicable. K. REFERENCES Marshall Aerospace and Defence Group Firefly T67 Maintenance Manual. L. OTHER PUBLICATIONS AFFECTED Not Applicable. M. INTERCHANGEABILITY/INTERMIXABILITY OF PARTS Not Applicable. 2.MA TERIAL INFORMA TION A. MATERIAL - PRICE AND AVAILABILITY Not Available. B. INDUSTRY SUPPORT INFORMATION Not Applicable. C. MATERIAL NECESSARY FOR EACH AIRCRAFT Loctite 222. Locking wire to DTD189A. 2 off Split Pins Pt. No. 120-15-132. Preparation 1 Inspection / Rectification 1 (excluding NDI inspection) Testing 1 Re-assembly 1 Records 1 Total 5 (excluding NDI inspection)

### MARSHALL AEROSPACE AND DEFENCE GROUP SERVICE BULLETIN



# SBM 200 Mar 15 Page 3 of 8 D. MATERIAL NECESSARY FOR EACH SPARE Not Applicable. E. REIDENTIFIED PARTS Not Applicable. F. TOOLING - PRICE AND AVAILABILITY Not Applicable. 3.ACCOMPLISHMENT INSTRUCTIONS A. MAINTENANCE PRACTICES W

ARNING: OBEY ALL WARNINGS, CAUTIONS AND MAINTENANCE PRACTICES. IF YOU DO NOT OBEY THIS WARNING THERE IS A RISK OF INJURY TO PERSONNEL AND/OR DAMAGE TO THE EQUIPMENT. (1) Observe all safety procedures. (2) All engineering and local procedures are to be observed whilst embodying this Service Bulletin. (3) After inspection ensure aircraft is clean and clear of tools and miscellaneous equipment and any removed parts are replaced. B. PREPARATION Prior to proceeding, ensure that the Service Bulletin has been read in its entirety and is understood. C. INSPECTION (1) Rudder pedal assembly #1: (a) Remove rudder pedal stop screw (1) and slide assembly aft from its housing. (b) Remove and discard locking wire (2). (c) Remove the split pin (3) and washer (4). Discard split pin. (d) Slide off lower inner bracket from main brake cylinder pivot after removing bracket, attached with 2 off socket head screws. (e) Displace brake cylinder (5) inboard to clear top pivot. (f) Remove pivot pin (6) by unscrewing. NOTE: The pivot pin is bonded in position.

### MARSHALL AEROSPACE AND DEFENCE GROUP SERVICE BULLETIN



# SBM 200 Mar 15 Page 4 of 8 (g) Carry out visual inspection of brake master cylinder pivot pin for damage, cracks or distortion (Reference Figure 1 and Figure 2). (h) Carry out visual inspection for dimensional accuracy of threaded portion of the brake master cylinder pivot pin (Reference Figure 1 and Figure 3). (Ensure that threaded portion is 5 mm in length, and adjacent shank is 2.5 mm in length). (i) Carry out NDI (fluorescent dye penetrant), using local regulations, of the brake master cylinder pivot pin threaded portion and shank where it enters the central barrel. (j) If any damage, crack or distortion to the brake master cylinder pivot pin is discovered or the pivot pin fails the dimensional requirement then it is considered to be unserviceable and is to be replaced. (k) If no damage, crack or distortion to the brake master cylinder pivot pin is found and the pivot pin meets the dimensional requirements, re-assemble in reverse of the removal procedure, using a new split pin. The pivot pin (6) is bonded in position using Loctite 222. Ensure that wire-locking does not foul on any adjacent structure or components. (2) Repeat Para 2.C1 to rudder pedal assembly #4. D. MODIFICATION Not applicable. E. TESTING (1) Carry out operational check of the rudder control system for full and free movement. (2) Carry out operational check of the aircraft wheel brake control system, IAW Aircraft Maintenance Manual P4-44, 4.7, ensuring no binding at the brake master cylinder pivots. F. COMPLETION (1) Annotate airframe logbook or aircraft record with - SBM 200 carried out (in accordance with local requirements). (2) Retain the damaged parts for further inspection and reported to Marshall Aerospace and Defence Group (MADG) using the User Experience Report (UER) system in accordance with the Aircraft Maintenance Manual. For any replaceable parts or materials contact Marshall Aerospace and Defence Group Product Support Department contact details as below: Mr M Bright Technical Group Support Engineer Marshall ADG The Airport Cambridge CB5 8RX UK Tel. No. +44 (0) 1223 399856 +44 (0) 7825365617 Email: mark.bright@marshalladg.com

### MARSHALL AEROSPACE AND DEFENCE GROUP SERVICE BULLETIN



# SBM 200 Mar 15 Page 5 of 8 Examination - Brake Master Cylinder Pivot Pin Figure 1

### MARSHALL AEROSPACE AND DEFENCE GROUP SERVICE BULLETIN



# SBM 200 Mar 15 Page 6 of 8 Pivot pin Figure 2

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# SBM 200 Mar 15 Page 7 of 8 Pivot pin threads Figure 3

### MARSHALL AEROSPACE AND DEFENCE GROUP SERVICE BULLETIN



# SBM 200 Mar 15 Page 8 of 8 SBM 200 ANNEX A BRAKE MASTER CYLINDER PIVOT PIN EXAMINATION This form is to be completed and submitted to the address below. Mr M Bright Technical Group Support Engineer Marshall ADG The Airport, Cambridge, CB5 8RX UK mark.bright@marshalladg.com

Aircraft works number SB 200 carried out Total Flight Hours Details of action required

Reporters contact details i.e. Name, Address, e-mail, telephone etc

Owner’s details