## SUBJECT 

# SERVICE BULLETIN

NUMBER 100-28-297

FUEL (ATA 28) – MAIN LANDING GEAR WHEEL WELL FUEL LINES - INSPECTION AND ADDITION OF LOOP CL AMPS BETWEEN FUEL LINES AND ELECTRIC AL HARNESSES

JANUARY 21 , 2010

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 1 of 12 FUEL - MAIN LANDING *($5 WHEEL WELL FUEL LINES - INSPECTIO N AND ADDITION OF LOOP CLAMPS BETWEEN FUEL LI NES AND ELECTR ICAL HARNESSES

PLANNING INFORMATION 100-28-297 1. Effectivity Aircraft serial number s 004 and 011 through 158 2. Concurrent Requirement None 3. Reason Recently, a G100 operator reported that re mnants of sponge-r ubber padding were found attached by cable tie-wraps to the f uel lines in the Main Landing Gear (MLG) wheel well. This padding is not approved for installati on and was not intended to provide clearance / separation between the fuel li nes and electrical harnesses. In addition, under some cable tie-wraps, corrosion was present, caused by moisture being trapped within the ope n sponge rubber shells. 4. Description This service bulletin provides instructions to remove the sponge-rubber padding from the fuel lines, inspect for corrosion, and tr eat and / or replace dam aged fuel lines as required. Additionally, instruct ions are provided to install loop clamps to achieve a minimum clearance of 0.5 inc hes (12.7 mm), between the f uel lines and electrical harnesses. 5. Compliance Compliance with this service bulletin is mandatory at the nex t suitable planned maintenance period within 24 months. 6. Approval This service bulletin has been re viewed by the Civil Aviati on Administration of Israel (CAAI). The design content herein comp lies with the applic able Civil Aviation Regulations and is CAAI approved.

January 21 , 2010

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 2 of 12 7. Manpower The following information is for planning purposes only: Estimated man-hours: 4 for inspection 14 for corrosion trea tment if necessary 7 for clamping procedure if necessary NOTE: Fuel line replacement if required, is not inclusive and will be quoted by the installing facility. 8. Weight and Balance None 9. Electrical Load Data No Change 10. Software Accomplishment Summary None 11. References Astra, Astra SPX and G100 Aircraft Ma intenance Manual (AMM), Chapters 20, 24 and 28 Gulfstream Aerospace LP Modification G1-10031 NOTE: The design of MOD G1-100 31 is configured to a standard type certificated configuration aircraft. Approval, by the local regulatory authority, of any deviation from the instruct ions contained in this service bulletin must be obtained, if required, in accordance with the rele vant local regulations. 12. Other Publications Affected Astra, Astra SPX and G1 00 AMM, Chapter 28 Astra, Astra SPX and G100 Illustrate d Parts Catalog (I PC), Chapter 28 NOTE: Data concerning this service bulletin wi ll be published in a future revision of the affected manual(s). This service bu ll etin will provide technical data until the revisions are published. 13. Interchangeability or In termixability of Parts None January 21 , 2010

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 3 of 12 MATERIAL INFORMATION

14. Material - Pric e and Availability The parts required to accomp lish this service bulletin are available by contacting Spare Parts Sales at 800-810 -GULF (4853) or 912-965-4178. 15. Warranty Coverage - Component None 16. 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 documentati on from IAI stating equivalence. A. Material to be Procured:

NOTE: MS21919WCF clamps may be subs tituted for AS21919WCF clamps. B. Materials Supplied by Operator: Abrasive Paper #400 grit or Scotch-Brite types 7447 ( Ro ugh) and 7448 (Fine) or equivalent Acetone Alodine 1200S or equivalent Fluid

- resistant epoxy primer-cl ass 2, per BMS 10-11, type 1 New Part No. Keyword Old Part No. Qty. AS21919WCF04 Loop Clamp

- A/R AS21919WCF05 Loop Clamp

- A/R AS21919WCF16 Loop Clamp

- A/R AS21919WCF20 Loop Clamp

- A/R AS21919WCF24 Loop Clamp

- A/R NAS1149C0332R Flat Washer

- A/R MS27039C1-09 Screw

- A/R MS21042L3 Nut

- A/R TA4070M0808 90 Deg. Bracket

- A/R

January 21, 2010

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 4 of 12 17. Reidentified Parts None 18. Special Tooling Concave mirror or a 10 X magnifying glass Digital handheld ultrasonic th ickness gauge or equivalent

January 21 , 2010

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 5 of 12 ACCOMPLISHMENT INSTRUCTIONS CAUTION: PROTECT WIRE BUNDLE S, CONNECTORS AND SURROUNDING STRUCTURE DURING ANY MAIN TENANCE PROCEDURES FROM SHAVINGS, DEBRIS AND CONTAMIN ATION. MAINTAIN A PROPERLY CLEANED WORK AREA THROUGHOUT THE PROCEDURE TO ENSURE THE INTEGRITY OF THE AFFECTED COMPONENT/SYSTEM. VISUALLY INSPECT WORK AREA US ING ADDITIONAL LIGH T 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 24. 3. Remove left and right MLG doors (16 and 16A) to gain access to the fuel lines listed below. Refer to AMM, Chapter 28 and Figure 1:

4. Rework Procedure: A. Perform detailed inspection for presence of sponge-rubber padding in the wheel well area, particularly on the fuel lines noted in Step 3. Refer to Figure 2. (1) If sponge-rubber is pr esent, perform the follow ing (refer to Figure 2, Sheet 1): (a) Document the sponge- rubber with a digital ca mera. Send photos to Gulfstream Customer Support via email at midcabin.techops@gulfstream.com P/N Description and Function DIA. X Wall Thk. 25W653120-539/-540 Wing tank vent - line connection from the fuselage to the bladder tank 1.00” x 0.035”
25W653120-637/-638 Main vent - li ne connection from the fuselage bladder tank to the NACA scoop 1.50” x 0.035”
25W653120-639/-640 Transfer line from the fuse lage bladder tank to the wing tank 1.25” x 0.035”

January 21 , 2010

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 6 of 12 (b) Cut all the cable tie- wraps attaching the sponge -rubber padding to the fuel lines. (c) Remove and dispose of cable- tie wraps and remnants of padding. NOTE: If there are any other fuel lines besides those indicated above that are also wrapped with sponge - rubber, remove the sponge-rubber from all affected fuel lines. (2) Perform a detailed visual inspection for corrosion on the fuel lines in the areas where sponge-rubber has been used and perform the following as necessary (refer to Figure 2, Sheet 2): (a) Remove corrosion using abrasive paper #400 grit or 3M Scotch-Brite Types 7447 (Rough) and 7448 (Fine) or equivalent. Blend the surrounding area to a ratio of 10:1 to the depth of the corrosion removed. (b) Clean the reworked area with acetone and wipe dry. (c) Ensure that all corro si on has been removed using a concave mirr or or a ten (10) X magnifying glass. (3) Measure the wall th ickness of areas where corrosion has been removed using a digital handhel d ultrasonic thickne ss gauge or equivalent. (a) Replace any tubes if the minimum thickness is less than follows (refer to IPC, Chapter 28 and AMM, Chapter 28): 1 0.028” for tubes with a nomi nal thickness of 0.035” (P/Ns 25W653120-539/-540/- 637/-638/-639/-640). 2 For others tubes in the immedi ate area that may have corrosion spots but with wall thickness of 0.028” rework to a minimum thickness of 0.022”. B. Treat reworked areas with Al odine type 1200S or equivalent. C. Apply fluid-resistant epo xy primer

- class 2, per BMS 10-11, type 1, to reworked areas. 5. Clamping procedure: NOTE: Inspect the fuel lines and electrical ha rn esses for separation as depicted in Figure 3, Sheets 1 and 2. The possibility exists that some aircraft may be configured as s hown in Figure 3. A. Install loop clamps (5, 6 or 7) to suit the diameters for each fuel tube. Refer to Figure 3, Details A, B and C. January 21 , 2010

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 7 of 12 B. Install loop clamps (1 or 9) to suit the diameters fo r the electric al harnesses. C. Secure the fuel line loop clamps and electrical harness loop clamps together using screws (4), P/N MS27039C1-09, washers (2), P/N NAS1149C0332R and nuts (3), P/N MS21042L3. D. Where any electrical harnesses intersect or meet fuel tubes , use bracket angle (8), P/N TA4070M0808, to connect the loop clamps . Refer to Figure 3, Detail C. 6. Reinstall left and right MLG doors (16 and 16A ). Refer to AMM, Chapter 28 and Figure 1. 7. Ensure work area is clean a nd clear of foreign objects (FOD). 8. Record compliance with this service bulletin in the airc raft’s permanent maintenance records and return aircra ft to flight status. 9. Report compliance with this service bulletin to Gulf stream CMP via electronic transmittal or fill out and fax the attached service reply card. NOTE: When reporting compliance with this service bulletin, ensure the questionnaire table within the service reply card is annotated. If technical assistan ce is required, contact your area Gulfstream Field Service Representative or call Gulf stream Customer Support at 800-810-GULF (4853) or 912-965-4178 (fax 912-965-4184).

January 21 , 2010

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 8 of 12 Landing Gear Access Doors Figure 1 January 21 , 2010

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 9 of 12 REMNANTS OF SPONGE

- RUBBER PADDING

TYPICAL REMNANTS OF SPONGE

- RUBBER PADDING LEFT WHEEL WELL SHOWN RIGHT OPPOSITE

OUTBOARDFORWARD

Wheel Well Inspection Area Figure 2 (Sheet 1) January 21 , 2010

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 10 of 12 Wheel Well Inspection Area Figure 2 (Sheet 2) January 21 , 2010

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 11 of 12 Installation of Clamps

Figure 3 (Sheet 1) January 21 , 2010 MINIMUM GAP 0.50 INCH LOCATION OF CLAMPS ADDED

# Gulfstream SERVICE BULLETIN

Service Bulletin No. 100-28-297 Page 12 of 12 MINIMUM GAP 0.50 INCH

Installation of Clamps

Figure 3 (Sheet 2) January 21 , 2010

## GULFSTREAM G100 SERVICE BULLETIN NO. 100-28-297 SERVICE REPLY CARD

Service Bulletin prepared by Gulfstream Ae rospace, 500 Gulfstream Road, P.O. Box 2206, Savannah, Georgia 31402-2206, USA. © 2010 Gulfstream Aerospace. All rights reserved, including the righ t 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, mech anical, or otherwise, without prior written permission of Gulfstream Aerospace. This technical data is controlled under the Export Adminis tration 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 BULLETI N HAS BEEN COMPLIED WITH:
SB CMP NUMBER A/C AIRCRAFT TYPE COMPLIANCE DATE 982970 ASTRA / ASTRA SPX / Gulfstream G100

AIRCRAFT HOURS: AIRCRAFT LANDINGS: PREVIOUSLY COMPLIED WITH: DATE:

NOT APPLICABLE: DATE: Sponge Rubber Installed? 

### Yes No Left Wheel Well Right Wheel Well Corrosion Present on Fuel Tubes? Left Wheel Well Right Wheel Well Is Separation Between Fuel Tubes & Harnesses as Depicted in Figure 3, Sheets 1 & 2? Left Wheel Well Right Wheel Well

SIGNATURE TITLE / CERTIFICATE NUMBER COMPANY

COMMENTS / SUGGESTIONS / ACTIONS TAKEN: