# Gulfstream Alert Service Bulletin 150-28A-146: No revision named - Rights: © Gulfstream Aerospace Corporation. Filed by the FAA in regulations.gov docket FAA-2012-0675; AD 2012-13-51 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Gulfstream Alert Service Bulletin 150-28A-146](https://openairdocs.org/service-documents/gulfstream/150-28a146.md) - Title as filed: U.S. DOT/FAA - Service Information - Pages: 17 - PDF: https://openairdocs.org/files/sha256/a2/de/a2dedf39628767561b96cf6267036241e5907060c1f303f3e92377b0b2cb1be2 - Page: https://openairdocs.org/service-documents/gulfstream/150-28a146/file/a2dedf396287 ## Text Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 SERVICE BULLETIN SUBJECT ALERT NUMBER 150-28A-146 FUEL (ATA 28) - INSPECTION OF LEFT AND RIGHT WING INBOARD VENT HOLES JUNE 22, 2012 ### Page 2 Gulfstream............................................. ALERT SERVICE BULLETIN Service Bulletin No. 150-28A-146 Page 1 of 15 FUEL - INSPECTION OF LEFT AND RIGHT WING INBOARD VENT HOLES PLANNING INFORMATION 202 1. Effectivity Aircraft serial numbers 201-290 2. Concurrent Requirement None 3. Reason Recent inspection of a G150 aircraft following flight revealed several fasteners protruding from the lower wing surface. Initial investigation of the wing interior revealed several structural rib assemblies damaged and separated from the wing plank. Further investigation has revealed the wing vent tube covered with sealant, essentially blocking the path for air to exit the wing during fueling operations and thermal expansion. Continued operation in this condition has the potential to compromise the integrity of the wing structure. The potential exists for this condition to be present on other aircraft. 4. Description This alert service bulletin provides instructions to inspect the 3/8 inch vent holes outboard of rib zero for debris or obstructions. Method 1 requires defueling of the wing and internal inspection, Method 2 may be performed only if the aircraft has 3000 pounds or less total fuel on board. 5. Compliance Compliance with this alert service bulletin is mandatory before further flight. 6. Approval This service bulletin contains no modification information that revises the approved configuration and therefore does not require regulatory agency approval. 7. Manpower The following information is for planning purposes only: Estimated man-hours (Method 1): 12 Estimated man-hours (Method 2): 16 June 22, 2012 ### Page 3 Gulfstream ALERT SERVICE BULLETIN Service Bulletin No. 150-28A-146 Page 2 of 15 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, 12, 20 and 28 12. Other Publications Affected None 13. Interchangeability or In termixability of Parts None June 22, 2012 ### Page 4 Gulfstream............................................. ALERT SERVICE BULLETIN Service Bulletin No. 150-28A-146 Page 3 of 15 MATERIAL INFORMATION 1. Material - Price and Availability The parts required to accomplish this alert service bulletin are available by contacting Spare Parts Sales at 800-810-GULF (4853) or 912-965-4178. 2. Opportunity for No Charge Compliance This alert service bulletin will be accomplished at no charge if performed at a Gulfstream G150 Authorized Warranty Repair Facility within the recommended compliance time stated in this document. If this alert service bulletin is performed at other than a Gulfstream G150 Authorized Warranty Repair Facility, the labor will be an owner responsibility. 3. Material Necessary for Each Aircraft A. Material to be Procured: None B. Materials Supplied by the Operator: None 4. Reidentified Parts None 5. Special Tooling Borescope Lockwire, P/N MS20995C.032 Flash light (Strong light) Mirror Petroleum jelly Torque wrench 0.0 to 50 inch-lbs. June 22, 2012 ### Page 5 Gulfstream ALERT SERVICE BULLETIN Service Bulletin No. 150-28A-146 Page 4 of 15 ACCOMPLISHMENT INSTRUCTIONS CAUTION: PROTECT WIRE BUNDLE S, 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 Aircraft Maintenance Manual, 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 Aircraft Maintenance Manual, Chapter 12. 3. Perform Inspection in accordance with method 1 or method 2 below. 4. Inspection Method 1 (refer to Figure 1, Sheets 1, 2 and Figure 4, Sheets 1 and 2): A. Defuel aircraft. Refe r to AMM, Chapter 12. B. Remove left wing access panel 521AB. Refer to Figure 1, Sheet 1 and AMM, Chapter 06. C. Remove right wing access panel 621AB. Refer to Figure 1, Sheet 2 and AMM, Chapter 06. D. Perform a detailed visual in spection (using a strong flash light and mirror) of the 3/8 inch vent holes for debris or obstruction located outboard of rib zero, internal-wing upper surface in the left and right wing. Refer to Figure 3, Sheets 1 and 2. E. The wing vent holes should be clear and free of any debris or obstructions. Refer to Figure 3, Sheets 1 and 2. F. If no defects or other anomalies are noted and vent holes are clear and free of debris or sealant, no further action is required. Proceed to Step 4.H. below. June 22, 2012 ### Page 6 Gulfstream ALERT SERVICE BULLETIN Service Bulletin No. 150-28A-146 Page 5 of 15 G. If any defects or any other anomalies are present, or vent openings are covered/sealed, contact Gulfstream Customer Support at 800-810-4853 or 912-965-4178 for further instructions. H. Reinstall left wing access panels 521AB. Refer to Figure 1, Sheet 1 and AMM, Chapter 06. I. Reinstall right wing acce ss panel 621AB. Refer to Figure 1, Sheet 2 and AMM, Chapter 06. J. If aircraft was defueled fo r inspection, refuel aircraft. Refer to AMM, Chapter 12. 5. Inspection Method 2 (refer to Fi gure 2 and Figure 3, Sheets 1 and 2): CAUTION: INSPECTION METHOD 2 MAY ONLY BE PERFORMED WITH TOTAL AIRCRAFT FUEL LEVEL BELOW 3000 POUNDS. A. Remove the left and right win g - to - fuselage fairings, P/N 25G3621110-503/-504. Refer to Figure 2. B. Cut lockwire and disconnect B-nut fittings fr om union. Refer to Figure 3, Sheets 1 and 2. C. Remove as necessary clamps, screws an d washers securing wing vent relief tube to the support structure. D. Using a borescope, inspect vent hole by inserting boroscope through fitting tube assembly, P/N 25G6537225-501. Inspect for debris/sealant blockage at wing vent orifice. E. If no defects or othe r anomalies are noted and vent hole is clear and free of debris or sealant, no further action is required. F. If any defects or any other anomalies are present, or vent opening is covered/sealed, contact Gulfstream Customer Support at 800-810-4853 or 912-965-4178 for further instructions. G. Repeat Steps 5.A. through 5. F. for right side vent tube. H. Connect B-nut fittings to left and right unions. Refer to Figure 3, Sheets 1 and 2. I. Tighten B-nut fittings to left and ri ght unions and secure with lockwire, P/N MS20995C.032 6. Ensure work area is clean a nd clear of foreign objects (FOD). June 22, 2012 ### Page 7 Gulfstream ALERT SERVICE BULLETIN Service Bulletin No. 150-28A-146 Page 6 of 15 7. Reinstall the left and ri ght wing - to - fuselage fairings, P/N 25G3621110-503/-504. Refer to Figure 2 and Figure 5, Sheets 1 and 2. NOTE: In order to allow correct and smooth installation of the fairing, it is critical to secure holding bolts in a sequence beginning with all horizontal central holes and then in an up and down horizontal sequence. Refer to Figure 5, Sheets 1 and 2. 8. Dip all bolt threads in petroleum jelly and se cure fairing using bolts (1, 3, 5 and 7), per the locations depicted in Figure 5, Sheet 1. Torque bolts to 20-25 inch-lb. (refer to Figure 5, Sheet 2 for torque sequence). 9. Record compliance with this alert servic e bulletin in the aircraft’s permanent maintenance record. 10. Report compliance with this alert service bulletin 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). June 22, 2012 ### Page 8 (OCR) Gulfstream ALERT SERVICE BULLETIN 521AB 00000O 00 FWD Left Wing Access Panel 521AB _ Figure 1, Sheet 1 June 22, 2012 Service Bulletin No. 150-28A-146 Page 7 of 15 ### Page 9 (OCR) Gulfstream ALERT SERVICE BULLETIN ACCESS PANEL 621AB FWD 0400000 00 Right Wing Access Panel 621AB Figure 1, Sheet 2 June 22, 2012 Service Bulletin No. 150-28A-146 Page 8 of 15 ### Page 10 (OCR) Gulfstream ALERT SERVICE BULLETIN WING - TO - FUSELAGE FAIRING LEFT SIDE SHOWN; RIGHT SIDE OPPOSITE odi Left Wing - to - Fuselage Fairing; Right Side Opposite Figure 2 June 22, 2012 Service Bulletin No. 150-28A-146 Page 9 of 15 ### Page 11 Gulfstream ALERT SERVICE BULLETIN Service Bulletin No. 150-28A-146 Page 10 of 15 REMOVE B-NUT FITTING AND INSERT BORESCOPE PROBE LEFT VENT TUBE ASSEMBLY , P/N RIGHT VENT TUBE ASSEMBLY, CUT LOCKWIRE FROM UNIO, LEFT VENT TUBE ASSEMBLY, P/N 25G6537225-501 SHOWN; RIGHT SIDE OPPOSITE SEE DETAIL A 25G6544683-501 SHOWN DETAIL A WING FITTING ASSEMBLY, P/N 25G6537225-501 (SAME P/N ON LEFT AND RIGHT WING) P/N 25G6544683-502 Left Wing Vent Fitting; Right Side Opposite Figure 3, Sheet 1 June 22, 2012 ### Page 12 Gulfstream ALERT SERVICE BULLETIN Service Bulletin No. 150-28A-146 Page 11 of 15 Left Wing Vent Fitting; Right Side Opposite Figure 3, Sheet 2 June 22, 2012 LEFT VENT TUBE ASSEMBLY , P/N 25G6537225-501 SHOWN, RIGHT SIDE OPPOSITE CUT LOCKWIRE FROM UNION, REMOVE B-NUT FITTING AND INSERT BORESCOPE PROBE HERE SEE DETAIL B DETAIL B ### Page 13 Gulfstream ALERT SERVICE BULLETIN Service Bulletin No. 150-28A-146 Page 12 of 15 Example of Vent Shown with no Sealant (Correct) Figure 4, Sheet 1 June 22, 2012 RIGHT SIDE SHOWN; LEFT SIDE OPPOSITE ### Page 14 Gulfstream ALERT SERVICE BULLETIN Service Bulletin No. 150-28A-146 Page 13 of 15 Example of Vent Shown Covered with Sealant (Incorrect) Figure 4, Sheet 2 June 22, 2012 LEFT SIDE SHOWN; RIGHT SIDE OPPOSITE ### Page 15 (OCR) Gulfstream ALERT SERVICE BULLETIN (1) BOLT P/N NAS1581C3T3 (45 PLACES) - (2) WING TO FUSELAGE FAIRING P/N 25G3621110-503 (LH) P/N 2503621110-504 (RH) (7) BOLT P/N NAS1581C3T4 (4 PLACES) - (3) BOLT P/N NAS1581C3T3 (14 PLACES) • (4) BOX AFT FAIRING (5) BOLT PIN NAS1581C3T3 (5 PLACES) NOTE: LEFT SHOWN RIGHT OPPOSITE Fuselage Fairing Bolt Locations Figure 5, Sheet 1 June 22, 2012 Service Bulletin No. 150-28A-146 Page 14 of 15 ### Page 16 (OCR) Gulfstream ALERT SERVICE BULLETIN 7313.0 7577.0 7841.0 8132.0 UP VIEW LOOKING INB'D SEAL, UPPER EDGE (REF) - 25G 3621110-503504 OPP RIB FAIRING (REF) - SEAL, LOWER EDGE NOTE: (REF) LEFT SHOWN RIGHT OPPOSITE TYPE SECTION A-A VIEW LOOKING AFT - RETAINER AND STRAP, SELF ADHESIVE (REF) NOTE: • IN ORDER TO ALLOW CORRECT AND SMOOTH INSTALLATION OF FAIRING IT IS REQUIRED TO SECURE HOLDING BOLTS IN A SEQUENCE BEGINNING WITH ALL HORIZONTAL CENTRAL HOLES AND THEN IN AN UP AND DOWN HORIZONTAL SEQUENCE. Fuselage Fairing Bolt Torque Sequence Figure 5, Sheet 2 June 22, 2012 Service Bulletin No. 150-28A-146 Page 15 of 15 ### Page 17 GULFSTREAM G150 ALERT SERVICE BULLETIN NO. 150-28A-146 SERVICE REPLY CARD Service Bulletin prepared by Gulfstream Aerospace, 500 Gulfstream Road, P.O. Box 2206, Savannah, Georgia 31402-2206, USA. © 2012 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 981460 Gulfstream G150 AIRCRAFT HOURS: AIRCRAFT LANDINGS: PREVIOUSLY COMPLIED W I T H : D A T E : NOT APPLICABLE: DATE: SIGNATURE TITLE / CERTIFICATE NUMBER COMPANY COMMENTS / SUGGESTIONS / ACTIONS TAKEN: --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.