# AD 90-06-18 R1: Wing Landing Gear Inspection - Type: Airworthiness directive - Status: Historical - Products: Boeing 747 Series (all) - Effective: August 17, 1990 - Superseded by: [AD 2001-17-25](https://openairdocs.org/ad/2001-17-25) - Product type: Aircraft, Large airplane - Amendment: 39-6706 - Docket: 89-NM-105-AD - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5F18799D9A63398C8625695E00721150.0001 - DRS record last changed: August 7, 2025 - Page: https://openairdocs.org/ad/90-06-18-R1 ## The airworthiness directive 90-06-18 R1 BOEING: Amendment 39-6541 as corrected by Amendment 39-6706. Docket No. 89-NM-105-AD. Applicability: Model 747 series airplanes, Groups 1, 2, and 3 as listed in Boeing Service Bulletin 747-32-2190, Revision 4, dated October 26, 1989, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent landing gear collapse during landing due to corrosion and fatigue cracks, accomplish the following: A. Inspect as follows: 1. Within the next 120 days after the effective date of this AD, perform a visual inspection, or a visual plus eddy current inspection, of the wing landing gear at the trunnion, for cracks and corrosion, in accordance with Boeing Service Bulletin 747-32-2190, Revision 4, dated October 26, 1989. 2. If no cracks or corrosion are found, repeat inspection described in paragraph A.1. of this AD at intervals not to exceed 6 months if the visual inspection option was selected for the previous inspection, or at intervals not to exceed 18 months if visual and eddy current inspection option was selected for the previous inspection. 3. Except as provided by paragraph A.4. below, if cracks or corrosion are found, prior to further flight, remove and rework or replace cracked/corroded parts in accordance with Boeing Service Bulletin 747-32-2190, Revision 4, dated October 26, 1989. 4. If only corrosion is found, as an alternative to paragraph A.3. of this AD, accomplish the terminating action described in Boeing Service Bulletin 747-32-2190, Revision 4, dated October 26, 1989, within 12 months after detection of corrosion, but no later than 36 months after the effective date of this AD; and high frequency eddy current inspect the wing landing gear trunnion at intervals not to exceed 6 months, until the terminating action is accomplished. B. Modification in accordance with Boeing Service Bulletin 747-32-2190, Revision 4, dated October 26, 1989, constitutes terminating action for the reinspection requirements of paragraph A. above. C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment, and then send it to the Manager, Seattle Aircraft Certification Office. D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124. This information may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., 5th Floor, Renton, Washington, or the Seattle Aircraft Certification Office, 1601 Lind Avenue S.W., 2nd Floor, Renton, Washington. Airworthiness Directive 90-06-18 R1 revises AD 90-06-18, Amendment 39-6541. The effective date for the requirements of this AD remains April 23, 1990, as specified in Amendment AD 90-06-18, Amendment 39-6541. This Amendment (39-6706, AD 90-06-18 R1) is effective on August 17, 1990. ## Registered aircraft it may apply to (OpenAirDocs) No registered aircraft matched the models it names. ## Related documents - [AD 2001-17-25](https://openairdocs.org/ad/2001-17-25): Wing Landing Gear Trunnion ยท Boeing 747-100 Series, 747-100B Series, 747-100B SUD Series and 9 more. Effective Oct 3, 2001. Supersedes this AD Its text cites no advisory circulars or STCs. ## NTSB investigations that cite this AD (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB FTW02IA061](https://openairdocs.org/ntsb/FTW02IA061), Jan 3, 2002: Boeing 747-228F (F-GCBG), Houston, TX, incident, minor damage. Probable cause: Stress corrosion cracking (SCC) of the aft trunnion outer cylinder. A factor was the inadequate inspection criteria of the Airworthiness Directive to detect pre-existing SCC. --- 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.