Gulfstream

TRANSMITTAL SHEET

Transmittal

Page 1 of 1

Galaxy-52-107Dec 02/2001Galaxy-52-107

This sheet transmits Revision 1, dated January 27, 2011, to Gulfstream Service 

Bulletin 150-27-123, dated October 27, 2010, titled Flight Controls - Aileron System - 

Inspection of Centering Spring Rod.

Reason for Revision

Planning Information, desciption statement updated providing simplified instructions

Material Information, removed Illustrated Part Catalog (IPC) reference

Accomplishment Instructions, updated providing simplified instructions.

Accomplishment Instructions, removed IPC note. 

Aircraft in compliance with the original issue of this service bulletin require no further 

action.

This is a COMPLETE REISSUE of Gulfstream Service Bulletin 150-27-123. 

List of Effective Pages

Previous revisions to service bulletin 150-27-123

None

Page No. Date

1 through 9 January 27, 2011

January 27, 2011
SERVICE BULLETIN

SUBJECT

 

 

 

 

NUMBER 150-27-123 Rev 1 

FLIGHT CONTROLS - (ATA 27) - AILERON 

SYSTEM - INSPECTION OF CENTERING 

SPRING ROD 

JANUARY 27, 2011 
Gulfstream

SERVICE BULLETIN

Service Bulletin No. 150-27-123

Page 1 of 9

This service bulletin revision supersedes all previous revisions of Service Bulletin (SB) 

150-27-123. Aircraft in compliance with the original issue of this service bulletin require 

no further action. Operators should fill out CMP card as previously complied with and 

return to Gulfstream Aerospace CMP.

FLIGHT CONTROLS - AILERON SYSTEM - INSPECTION 

OF CENTERING SPRING ROD

PLANNING INFORMATION

150-27-123

1. Effectivity

Aircraft serial numbers 201 through 286

2. Concurrent Requirement

None

3. Reason

During a routine inspection, an aileron servo actuator centering spring rod was found 

broken. 

4. Description

This service bulletin revision provides simplified instructions to perform a one-time 

detailed inspection of the aileron servo actuator centering spring rod to verify the rod is 

not broken.

5. Compliance

Compliance with this service bulletin is mandatory at the next suitable planned 

maintenance period within 12 months from the original release date of this service 

bulletin.

6. Approval

This service bulletin revision has been reviewed by the Civil Aviation Authority of Israel 

(CAAI). The design content herein complies with the applicable Civil Aviation 

Regulations and is CAAI approved.

7. Manpower

The following information is for planning purposes only:

Estimated man-hours: 10 

October 27, 2010

Revision 1 January 27, 2011
Gulfstream 

SERVICE BULLETIN

Service Bulletin No. 150-27-123

Page 2 of 9

8. Weight and Balance

None

9. Electrical Load Data

No Change

10. Software Accomplishment Summary

None

11. References

G150 Aircraft Maintenance Manual (AMM), Chapters 06, 20 and 27

12. Other Publications Affected

G150 AMM, Chapters 05 and 27

13. Interchangeability or Intermixability of Parts

None

October 27, 2010

Revision 1 January 27, 2011
Gulfstream

SERVICE BULLETIN

Service Bulletin No. 150-27-123

Page 3 of 9

MATERIAL INFORMATION

1. Material - Price and Availability

The parts required to accomplish this service bulletin are available by contacting 

Spare Parts Sales at 800-810-GULF (4853) or 912-965-4178.

2. Warranty Coverage - Component

Labor and materials will be at no charge if the aircraft is still within the relevant warranty 

periods and this Service Bulletin is accomplished within the recommended compliance 

time, as stated in this document, at a Gulfstream G150 Authorized Warranty Repair 

Facility. * 

*Coverage is granted per the terms and conditions of the Gulfstream Aircraft Sales 

Agreement to the original purchaser or subsequent owner with appropriate Assignment 

of Warranties on file with Gulfstream.

3. Material Necessary for Each Aircraft

NOTE: The parts listed in this section can be substituted with equivalent Israel 

Aerospace Industries (IAI) approved parts. If equivalent part(s) is used, it 

must be accompanied by documentation from IAI stating equivalence.

A. Material to be Procured:

NOTE: If centering spring rod(s) require replacement, contact Gulfstream 

Aerospace Customer Support at 800-810-GULF (4853) or 

912-965-4178 for replacement instructions. 

B. Materials Supplied by Operator:

None

4. Reidentified Parts

None

5. Special Tooling

GSE rig pin, P/N GSE27200364

New P/N Keyword Old P/N Qty

MS24665-151 Cotter Pin - A/R

October 27, 2010

Revision 1 January 27, 2011
Gulfstream 

SERVICE BULLETIN

Service Bulletin No. 150-27-123

Page 4 of 9

ACCOMPLISHMENT INSTRUCTIONS

CAUTION: PROTECT WIRE BUNDLES, CONNECTORS AND SURROUNDING 

STRUCTURE DURING ANY MAINTENANCE PROCEDURES FROM 

SHAVINGS, DEBRIS AND CONTAMINATION. MAINTAIN A PROPERLY 

CLEANED WORK AREA THROUGHOUT THE PROCEDURE TO ENSURE THE 

INTEGRITY OF THE AFFECTED COMPONENT/SYSTEM. VISUALLY 

INSPECT WORK AREA USING ADDITIONAL LIGHT AS NECESSARY TO 

VERIFY ABSENCE OF ANY DEBRIS PRIOR TO COMPLETION OF 

PROCEDURE. FAILURE TO COMPLY MAY RESULT IN DAMAGE TO 

COMPONENTS AND/OR SYSTEMS.

1. Prepare aircraft for safe maintenance. Refer to AMM, Safe Ground Maintenance 

Procedure, Chapter 20.

CAUTION: MAKE SURE ELECTRICAL POWER IS DISCONNECTED FROM AIRCRAFT. 

FAILURE TO COMPLY MAY RESULT IN INJURY TO PERSONNEL AND/OR 

DAMAGE TO AIRCRAFT.

2. Disconnect external electrical power from aircraft. Refer to AMM, Chapter 20.

3. Remove left and right wing access panels 521GL, 521HL, 621GR and 621HR. Refer 

to AMM, Chapter 06 and Figure 1, Sheets 1 and 2.

4. Apply electrical power to aircraft. Refer to AMM, Chapter 20.

WARNING: FAILURE TO ENSURE ALL PERSONNEL AND EQUIPMENT ARE CLEAR OF 

FLIGHT CONTROL SURFACES BEFORE OPERATING FLIGHT CONTROLS 

MAY RESULT IN SERIOUS INJURY OR DEATH.

5. Apply external hydraulic power to aircraft. Refer to AMM, Chapter 20. 

6. Insert rig pin, P/N GSE27200364, in bell crank at rib 6. Refer to AMM, Chapter 27.

NOTE: To access the bell crank at rib 6, a small circular access panel must be 

removed. The panel is just aft of the wing leading edge on the lower side of 

the wing in the rib 6 area. The panel is secured with 3 fasteners. 

7. Remove hydraulic power from aircraft. Refer to AMM, Chapter 20.

8. Remove electrical power from aircraft. Refer to AMM, Chapter 20.

9. Disconnect the centering spring arm from the aileron servo actuator. Refer to Figure 2, 

Sheet 2. Discard cotter pin, retain hardware for reinstallation. 

October 27, 2010

Revision 1 January 27, 2011
Gulfstream

SERVICE BULLETIN

Service Bulletin No. 150-27-123

Page 5 of 9

10. Perform a detailed tactile inspection of the left and right aileron centering spring rod. 

The rod should be grasped and shaken/moved in all axes using moderate force 

applied by hand through the openings for access panels 521GL, 521HL, 621GR and 

621HR, to verify its integrity. Refer to Figure 2, Sheets 1 and 2.

11. Apply moderate torsional load by hand on the centering spring rod using the attached 

linkage segments to further confirm the finding in Step 11, that the rod is intact. The 

rod should provide torsional resistance to the load applied by hand through the 

linkage segments. Refer to Figure 2, Sheets 1 and 2.

NOTE: If any rod is found fractured or broken, contact Gulfstream Aerospace 

Customer Support at 800-810-4853 or 912-965-4178 for replacement 

instructions.

12. Apply electrical power to the aircraft. Refer to AMM, Chapter 20.

WARNING: FAILURE TO ENSURE ALL PERSONNEL AND EQUIPMENT ARE CLEAR OF 

FLIGHT CONTROL SURFACES BEFORE OPERATING FLIGHT CONTROLS 

MAY RESULT IN SERIOUS INJURY OR DEATH.

13. Apply hydraulic pressure to the actuator. Refer to AMM, Chapter 20.

14. Reconnect the centering spring arm and safety with cotter pin, P/N MS24665-151. 

Refer to Figure 2, Sheet 2. Ensure the centering spring rod is not preloaded.

15. Remove hydraulic power from aircraft. Refer to AMM, Chapter 20.

16. Remove electrical power from aircraft. Refer to AMM, Chapter 20.

17. Remove rig pin and reinstall access panel with 3 fasteners.

18. Ensure work area is clean and clear of foreign objects (FOD).

19. Install left and right wing access panels 521GL, 521HL, 621GR and 621HR. Refer to 

AMM, Chapter 06 and Figure 1, Sheets 1 and 2.

20. Record compliance with this service bulletin revision in the aircraft’s permanent 

maintenance records and return aircraft to flight status.

21. Report compliance with this service bulletin revision to Gulfstream CMP via electronic 

transmittal or fill out and fax the attached service reply card. 

If technical assistance is required, contact your area Gulfstream Field Service 

Representative or call Gulfstream Customer Support at 800-810-GULF (4853) or 

912-965-4178 (fax 912-965-4184).

October 27, 2010

Revision 1 January 27, 2011
Gulfstream 

SERVICE BULLETIN

Service Bulletin No. 150-27-123

Page 6 of 9 SB150-27-123-001-S01

VIEW LOOKING UP

Left Wing Access Panels

Figure 1 (Sheet 1 of 2)

October 27, 2010

Revision 1 January 27, 2011
Gulfstream 

SERVICE BULLETIN

Service Bulletin No. 150-27-123

Page 7 of 9

B

B

VIEW LOOKING UP

SB150-27-123-001-S02

Right Wing Access Panels

Figure 1 (Sheet 2 of 2)

October 27, 2010

Revision 1 January 27, 2011
Gulfstream 

SERVICE BULLETIN

Service Bulletin No. 150-27-123

Page 8 of 9

LH SHOWN, RH OPPOSITE

SB150-27-123-002-S01

CENTERING SPRING ROD

DISCONNECT LINKAGE HERE

DETAIL A

PILOT INPUT

CENTERING SPRING ROD

CENTERING SPRING

ARM

AILERON SERVO

ACTUATOR

HYDRAULIC TUBE

(REF)

A

FWD

Aileron Servo Actuator Centering Spring Rod

Figure 2 (Sheet 1)

October 27, 2010

Revision 1 January 27, 2011
Gulfstream 

SERVICE BULLETIN

Service Bulletin No. 150-27-123

Page 9 of 9

DISCONNECT LINKAGE HERE

CENTERING SPRING ARM

SB150-27-123-002-S02

Aileron Servo Actuator Centering Spring Rod Arm

Figure 2 (Sheet 2)

October 27, 2010

Revision 1 January 27, 2011
GULFSTREAM G150 

SERVICE BULLETIN NO. 150-27-123 Rev 1 

SERVICE REPLY CARD

Service Bulletin prepared by Gulfstream Aerospace, 500 Gulfstream Road, P.O. Box 2206, Savannah, Georgia 

31402-2206, USA. © 2011 Gulfstream Aerospace. All rights reserved, including the right to reproduce this publication. 

No part may be reproduced, stored in any retrieval system, or transmitted in any part or form or by any means, 

electronic, photocopying, microfilm, microfiche, mechanical, or otherwise, without prior written permission of 

Gulfstream Aerospace. This technical data is controlled under the Export Administration Regulations by General 

License TSU. It may not be transferred to a third party without the prior written approval of the U.S. Department of 

Commerce. 

PLEASE FAX THIS PAGE TO GULFSTREAM AEROSPACE CMP 

FAX # 800-944-1775 or 912-963-0265. 

THE FOLLOWING SERVICE BULLETIN HAS BEEN COMPLIED WITH: 

SB CMP NUMBER A/C AIRCRAFT TYPE COMPLIANCE DATE

981231 Gulfstream G150 

AIRCRAFT HOURS: AIRCRAFT LANDINGS: 

PREVIOUSLY COMPLIED 

WITH: DATE: 

NOT APPLICABLE: DATE: 

 

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