# CUSTOMER BULLETIN

SUBJECT 

# ALERT

NUMBER 21

WINGS (ATA 57)

INSPECTION – AFT INBOARD WING-TOFUSELAGE ATTACH FITTING

MAY 18, 2012Gulfstream III Alert Customer Bulletin No. 21 “May 18, 2012”

Page 1 of 3 Wings (ATA 57), Inspection – Aft Inboard Wing-to-Fuselage Attach Fitting

I. Planning Information:

A. Effectivity:

Gulfstream III aircraft, serial numbers 346, 355, 385 and 486

B. Reason:

Gulfstream released GIII ASC 229 in May of 1991 to provide a corrosion repair, without requiring wing de-mate, for the aft inboard attach fitting location. During a recent inspection, a GIII aircraft was found with a repair doubler that was trimmed beyond blueprint limits. Incorrect machining of the doublers results in improper mating of the clothes-pin fittings. The resulting excessive clearance between the structural members results in a change in load path and reduced structural strength of the assembly below certified limits. As a result of reduced strength, catastrophic failure of the aircraft may result. The above aircraft have been identified as having ASC 229 installed with the potential to have this condition.

C. Description:

This alert customer bulletin is a one-time action to inspect the aft inboard wing-tofuselage attach fitting doubler plate.

Note: All ASC references in this document are intended to be inclusive of any amendments or revisions unless otherwise stated.

D. Compliance:

Compliance with this alert customer bulletin is required before further flight.

E. Approval:

This alert customer bulletin has been FAA approved as this issue is the subject of FAA Airworthiness action. It does not contain any modification information nor revise the approved configuration and as such does not require any other regulatory approval.

F. Manpower:

Inspection - 2 man-hours per side

G. Material:

None

H. References:

GIII Aircraft Maintenance Manual (AMM), Chapter 57Gulfstream III Alert Customer Bulletin No. 21 “May 18, 2012”

Page 2 of 3 I. Tooling/Equipment:

Standard aircraft maintenance tools

J. Warranty Coverage:

None

K. Weight and Balance:

N/A

II. Accomplishment Instructions:

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.

A. Prepare aircraft for safe maintenance as follows:

1. Remove electrical power, turn all cockpit switches off and disconnect battery quick disconnects.

B. Gain access to the left and right wing aft inboard attach fittings and proceed as follows:

1. If necessary, remove any fillet seal from around the seal plate / doubler and clothespin fitting.

2. Inspect the clearance (gap) of exposed rounded portion of the clothespin fitting between the chromed area of the fitting and the doubler (see Figure 1). Cumulative measurements of Gaps A and B must not exceed 0.0046” maximum. If clearance exceeds 0.0046 inch contact Gulfstream Customer Support at 800-810-GULF or 912-965-4178 for further assistance. Record measurements in the Comments section of the attached Service Reply Card.

3. Clean the attach fitting area of all debris. If the fillet seal was removed reapply per GIII AMM Chapter 57.

C. Ensure work area is clean and clear of foreign objects (FOD).

D. Record compliance with this alert customer bulletin in the aircraft’s permanent maintenance records and return aircraft to flight status.

E. Fax a copy of the Service Reply Card with measurements found to Gulfstream Customer Support at 912-963-0219.Gulfstream III Alert Customer Bulletin No. 21 “May 18, 2012”

Page 3 of 3 F. Report compliance with this alert customer bulletin to Gulfstream Computerized Maintenance Program (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).

View Looking Forward, Right Wing Inboard Fitting (Inset View, Cutaway of Pin, Wing plank and Doubler) 

## Figure 1 Doubler

Clothespin
Fittin g Cumulative Measurements of Gaps A and B between chromed area and doubler must not exceed 0.0046” Maximum

Wing Plank Seal Plate (Not shown in inset)

Gap A Gap BGulfstream III Alert Customer Bulletin No. 21 “May 18, 2012”

Customer 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 pub lication. No part may be reproduced, stored in any retrieval syst em, or transmitted in any part or form or by any means, electronic, photocopying, micr ofilm, microfiche, mechanical, or otherwise, without prior written permission of Gu lfstream Aerospace.

This technical data is controlled under the Ex port Administration Regulations by General License TSU. It may not be transferre d to a third party without the prior written approval of the U.S. Department of Commerce.

GA 611A 2/97 

## Service Reply Card

Please fax this page to Gulfstream CMP at 800-944-1775 or 912-963-0265.

The following Alert Customer Bulletin (ACB) has been addressed:

CB Number A/C A/C Type Compliance Date

990210 GIII

Aircraft Hours Aircraft Landings

This Alert Customer Bulletin is not applicable because:

Serial Number not affected Appliance not installed ______Previously complied with (annotate method of compliance below)

Signature Title/Certificate Number Company

Comments / Suggestions: Right Side Pin: Inboard Gap _______ Outboard Gap _______ Left Side Pin: Inboard Gap _______ Outboard Gap _______