# Gulfstream Customer Bulletin 244: No revision named - Rights: © Gulfstream Aerospace Corporation. Filed by the FAA in regulations.gov docket FAA-2021-0881; AD 2022-02-15 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Gulfstream Customer Bulletin 244](https://openairdocs.org/service-documents/gulfstream/cb-244.md) - Title as filed: CB244 IV - Pages: 6 - PDF: https://openairdocs.org/files/sha256/ed/4d/ed4d8907ed12a4f1f8bc4256df591093c512956293b62098dc813c053b17da9c - Page: https://openairdocs.org/service-documents/gulfstream/cb-244/file/ed4d8907ed12 ## Text Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 CUSTOMER BULLETIN SUBJECT NUMBER 244 LANDING GEAR (ATA 32) REPLACEMENT – NOSE WHEEL STEERING SERVO VALVE MANIFOLD ASSEMBLY MARCH 12, 2018 ### Page 2 Gulfstream IV Customer Bulletin No. 244 March 12, 2018 Page 1 of 4 Landing Gear (ATA 32), Replacement – Nose Wheel Steering Servo Valve Manifold Assembly I. Planning Information: A. Effectivity: Aircraft serial numbers 1000 through 1535 B. Reason: Un-commanded nose wheel steering events on Gulfstream IV aircraft have been caused by moisture intrusion into the nose wheel steering servo valve manifold assembly. Gulfstream issued Customer Bulletin (CB) 219, Landing Gear (ATA 32), Modification – Nose Wheel Steering Servo Valve Upgrade, dated October 5, 2011, to address a known design issue by replacing existing servo valve manifold assemblies with upgraded units having hermetically sealed servo valves. Further investigation has identified supplier assembly procedures which may have introduced foreign objects and/or caused seal damage, contributing to the moisture intrusion problem. Improved steering servo valve manifold assemblies, P/N 5100-11 and 5105-5, incorporate the servo valve design change implemented by CB 219 with enhanced assembly procedures and quality control measures to ensure the designed level of sealing is achieved. This customer bulletin removes all existing steering servo valve manifold units and replaces them with improved assemblies. This customer bulletin supersedes CB 219. Op erators having previously complied with CB 219 or CB 219A must comply with this customer bulletin to install improved nose wheel steering servo valve manifold assemblies. C. Safety Intent: The safety intent of this customer bulletin is to prevent moisture intrusion into the nose wheel steering servo valve. Moisture intrusion that freezes in the nose wheel steering servo valve may cause uncommanded deflection of the nose wheel during touchdown, resulting in an unsafe condition and potential runway departure. D. Configuration Description: There is no change to the aircraft configuration. E. Description: This customer bulletin is a one-time action to replace the existing nose wheel steering servo valve manifold assemblies with improved units, P/N 5100-11 or 5105-5. F. Compliance: Compliance with this customer bulletin is r equired within 48 months from the original issue date of March 12, 2018. Due to a limited number of spares being available at any one time, compliance with this customer bulletin is a managed program and must be coordinated with the Program Office at pmoretro@gulfstream.com or through Gulfstream Scheduling at 800-810-GULF (4853), or 912-965-4178. If not scheduled, down times could increase significantly. ### Page 3 Gulfstream IV Customer Bulletin No. 244 March 12, 2018 Page 2 of 4 G. Approval: The engineering aspects of this customer bulletin have been reviewed and approved by the Federal Aviation Administration, and are the subject of pending Airworthiness Directive regulatory action. H. Manpower: Replacement - 7.0 labor hours I. Material: Part Number Nomenclature / Specification Quantity 5100-11* Valve, Servo As required 5105-5** Valve, Servo As required NAS1612-6A O-Ring 4 each * Aircraft serial numbers 1000 – 1242 not having Aircraft Service Change (ASC) 260 or ASC 260A ** Aircraft serial numbers 1000 – 1242 having ASC 260 or ASC 260A and aircraft 1243 - 1535 J. References: GIV Aircraft Maintenance Manual (AMM), Chapter 32 GIV Illustrated Parts Catalog (IPC), Chapter 32 GIV Customer Bulletin (CB) 219 NOTE: All references in this document are intended to be inclusive of any amendments or revisions unless otherwise stated. K. Tooling/Equipment: Standard aircraft maintenance tools L. Opportunity for No Charge Compliance: The labor and material to comply with this customer bulletin will be provided at no charge, regardless of warranty status, if accomplished within the recommended compliance time, as stated in this document, at a Gulfstream IV Authorized Warranty Facility or Factory Authorized Service Center. If this customer bulletin is performed at other than a Gulfstream facility, as stated above, materials will be provided free of charge but the labor will be an owner responsibility. M. Weight and Balance: N/A ### Page 4 Gulfstream IV Customer Bulletin No. 244 March 12, 2018 Page 3 of 4 II. Accomplishment Instructions: WARNING: FAILURE TO INSTALL ALL LANDING GEAR AND LANDING GEAR DOOR SAFETY DEVICES BEFORE WORKING IN ANY WHEEL WELL MAY RESULT IN INJURY OR DEATH. FAILURE TO DISSIPATE HYDRAULIC PRESSURE BEFORE INSTALLING OR REMOVING ALL LANDING GEAR AND LANDING GEAR DOOR SAFETY DEVICES SHALL CAUSE DAMAGE TO AIRCRAFT OR MAY RESULT IN INJURY OR DEATH. CAUTION: PROTECT WIRE BUNDLES, CONNECTORS AND SURROUNDING STRUCTURE DURING ANY MAINTENANCE PROCEDURE 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 NECESSA RY TO VERIFY ABSENCE OF ANY DEBRIS PRIOR TO COMPLETION OF PROCEDURE. FAILURE TO COMPLY MAY RESULT IN DAMAGE TO COMPONENTS AND / OR SYSTEMS. NOTE: Some steps in the accomplishment instructions are identified as Required for Compliance (RC). If this CB is mandated by an airworthiness directive (AD), the steps identified as RC must be done to comply with the AD. Steps not identified with RC are recommended and may be deviated from, done as part of other actions, or done with accepted methods different from those given in the CB, if the RC steps can be done and the aircraft can be put back in service in a serviceable condition. A. Open nose landing gear doors. Refer to AMM, Ground Service Provisions, Landing Gear Doors – Operation, Chapter 32. B. Prepare the aircraft for safe maintenance as follows: 1. Remove electrical power, turn all cockpit switches off and disconnect battery quick disconnects. C. Gain access to the Nose Wheel Steering (NWS) servo valve manifold assembly. See Figure 1. NOTE: The NWS servo valve manifold assembly is located on the left side of the nose wheel well at Fuselage Station (FS) 109, Water Line (WL) 58. D. RC: Remove the NWS servo valve manifold assembly. Refer to AMM, Nose Wheel Steering Servo Valve Manifold Assembly – Removal / Installation, Chapter 32. NOTE: Remove and retain the hydraulic line reducers from the NWS servo valve manifold assembly and install new O-rings. Reducers must be installed on the replacement NWS servo valve manifold assembly in order to install the hydraulic lines. E. RC: Install replacement NWS servo valve manifold assembly. See Step I.I. Material, for correct servo valve PN. Refer to AMM, Nose Wheel Steering Servo Valve Manifold Assembly – Removal / Installation, Chapter 32. F. Ensure work area is clean and clear of foreign objects (FOD). G. Record compliance with this customer bulletin in the aircraft’s permanent maintenance records and return aircraft to flight status. ### Page 5 Gulfstream IV Customer Bulletin No. 244 March 12, 2018 Page 4 of 4 H. Report compliance with this customer bulletin to Gulfstream Computerized Maintenance Program (CMP) by uploading the attached service reply card, along with the CMP task card(s) sign-off using MyGulfstream, MyCMP Document Upload or e-mail to cmp.docproc@campsystems.com or fax to Gulfstream CMP at 800-944-1775 or 912- 963-0265. 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. Location of NWS Servo Valve Manifold Assembly Figure 1 ### Page 6 Gulfstream IV Customer Bulletin No. 244 March 12, 2018 Customer Bulletin prepared by Gulfstream Aerospace, 500 Gulfstream Road, P.O. Box 2206, Savannah, Georgia 31402-2206, USA. © 2018 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. GA 611A 2/97 Service Reply Card Please upload this page, along with the CMP task card(s) sign-off using MyGulfstream, MyCMP Document Upload, or e-mail to cmp.docproc@campsystems.com or fax to Gulfstream CMP at 800-944-1775 or 912-963-0265. The following Customer Bulletin (CB) has been addressed: CB Number A/C A/C Type Compliance Date 982440 GIV Aircraft Hours Aircraft Landings This Customer Bulletin is not applicable because: Serial Number not affected Equipment not installed ______Previously complied with (annotate method of compliance below) ______Other (explain reason below) Signature Title/Certificate Number Company Comments / Suggestions: --- 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.