# SERVICE BULLETIN

SUBJECT 

# ALERT

NUMBER 150-28A-146

FUEL (ATA 28) - IN SPECTION OF LEFT AND RIGHT WING INBOARD VENT HOLES

JUNE 22, 2012

# 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 su rface. 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 t ube covered with sealant, essentially blocking the path for air to exit the wing during fueling op erations and thermal expansion. Continued operation in this condi tion has the potential to co mpromise the integrity of the wing structure. The potential exists for this condition to be pres ent on other aircraft. 4. Description This alert service bulletin pr ovides instructions to ins pect the 3/8 inch vent holes outboard of rib zero for debris or obstructions. Met hod 1 requires defueling of the wing and internal inspection, Method 2 may be performed onl y if the aircraft has 3000 pounds or less to tal fuel on board. 5. Compliance Compliance with this alert service bulleti n is mandatory before further flight. 6. Approval This service bulletin contains no modification information that revises the approved configuration and theref ore does not require regul atory 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

# 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 Maint enance Manual (AMM) C hapters 06, 12, 20 and 28 12. Other Publications Affected None 13. Interchangeability or In termixability of Parts None

June 22, 2012

# 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 ac complish this alert service bullet in 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 Authoriz ed Warranty Repair Facility within the recommended compliance time stated in this document. If this alert serv ice bulletin is performed at other than a Gulfstream G150 Authorized Warr anty Repair Facility, th e 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

# 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 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 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. Refe r 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 flas h light and mi rror) of the 3/8 inch vent holes for debris or obstruction loca ted 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

# Gulfstream ALERT SERVICE BULLETIN

Service Bulletin No. 150-28A-146 Page 5 of 15 G. If any defects or any other anomalies are pr esent, or vent openings are covered/sealed, contact Gulfstream Customer Support at 800-810-4853 or 912-965-4178 for furt her 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 Fi gure 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 fu rther action is required. F. If any defects or any other anomalies are pr esent, or ve nt opening is covered/sealed, contact Gulfstream Customer Support at 800-810-4853 or 912-965-4178 for furt her 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

# Gulfstream ALERT SERVICE BULLETIN

Service Bulletin No. 150-28A-146 Page 6 of 15 7. Reinstall the left and ri ght wing - to - fuselage fair ings, 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 beginni ng with all hori zontal 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 Figur e 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 ai rcraft’s permanent maintenance record. 10. Report compliance with this alert service bulletin to Gu lfstream CMP via electronic transmittal or fill out and fax the attached service reply card. 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).

June 22, 2012

# Gulfstream ALERT SERVICE BULLETIN

Service Bulletin No. 150-28A-146 Page 7 of 15 Left Wing Access Panel 521AB Figure 1, Sheet 1 June 22, 2012 521AB

# Gulfstream ALERT SERVICE BULLETIN

Service Bulletin No. 150-28A-146 Page 8 of 15 ACCESS PANEL 621AB

Right Wing Access Panel 621AB Figure 1, Sheet 2 June 22, 2012

# Gulfstream ALERT SERVICE BULLETIN

Service Bulletin No. 150-28A-146 Page 9 of 15 Left Wing - to - Fuselage Fa iring; Right Side Opposite Figure 2 June 22, 2012 WING - TO - FUSELAGE FAIRING LEFT SIDE SHOWN; RIGHT SIDE OPPOSITE

# 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

# 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

# Gulfstream ALERT SERVICE BULLETIN

Service Bulletin No. 150-28A-146 Page 12 of 15 Example of Vent Shown wi th no Sealant (Correct) Figure 4, Sheet 1 June 22, 2012 RIGHT SIDE SHOWN; LEFT SIDE OPPOSITE

# Gulfstream ALERT SERVICE BULLETIN

Service Bulletin No. 150-28A-146 Page 13 of 15 Example of Vent Shown Cove red with Sealant (Incorrect) Figure 4, Sheet 2 June 22, 2012 LEFT SIDE SHOWN; RIGHT SIDE OPPOSITE

# Gulfstream ALERT SERVICE BULLETIN

Service Bulletin No. 150-28A-146 Page 14 of 15 Fuselage Fairing Bolt Locations Figure 5, Sheet 1 June 22, 2012

# Gulfstream ALERT SERVICE BULLETIN

Service Bulletin No. 150-28A-146 Page 15 of 15 Fuselage Fairing Bo lt Torque Sequence Figure 5, Sheet 2 June 22, 2012

## GULFSTREAM G150 ALERT SERVICE BULLETIN NO. 150-28A-146 SERVICE REPLY CARD

Service Bulletin prepared by Gulfstream Aerospace, 500 Gulfstream Road, P.O. Bo x 2206, Savannah, Georgia 31402-2206, USA. © 2012 Gulfstream Aerospac e. All rights reserved, including the ri ght to reproduce this publication. No part may be reproduced, stored in any retrieval syst em, or transmitted in any part or form or by any means, electronic, photocopying, microfilm, mi crofiche, mechanical, or otherwise, without prior written permission of Gulfstream Aerospace. This technical data is controll ed under the Export Administration Regulations by General License TSU. It may not be transferred to a third party with out 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 981460 Gulfstream G150

AIRCRAFT HOURS: AIRCRAFT LANDINGS: PREVIOUSLY COMPLIED WITH: DATE: NOT APPLICABLE: DATE:

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