ALERT SERVICE BULLETIN No. 150-28A-146

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S E R V I C E B U L L E T I N S U B J E C T ALERT NUMBER 150-28A-146 FUEL (ATA 28) - INSPECTION 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 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 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 Intermixability 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 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 Gulfstream ALERT SERVICE BULLETIN Service Bulletin No. 150-28A-146 Page 4 of 15 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 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. Refer 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 inspection (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 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 access panel 621AB. Refer to Figure 1, Sheet 2 and AMM, Chapter 06. J. If aircraft was defueled for inspection, refuel aircraft. Refer to AMM, Chapter 12. 5. Inspection Method 2 (refer to Figure 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 wing - to - fuselage fairings, P/N 25G3621110-503/-504. Refer to Figure 2. B. Cut lockwire and disconnect B-nut fittings from union. Refer to Figure 3, Sheets 1 and 2.