# AD 90-23-16: Gear Selector Valve - Type: Airworthiness directive - Status: Current - Products: Boeing 747-100 Series, 747-100B Series, 747-100B SUD Series, 747-200B Series, 747-200C Series, 747-200F Series, 747-300 Series, 747-400 Series, 747-400D Series, 747-400F Series, 747SP Series and 747SR Series - Effective: November 12, 1990 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-6792 - Docket: 90-NM-202-AD - Registered aircraft: 63 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B79682F6E2E418D58625696000723311.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/90-23-16 ## The airworthiness directive 90-23-16 BOEING: Amendment 39-6792. Docket No. 90-NM-202-AD. Applicability: Model 747 series airplanes, line position 002 through 803, and 806 certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent partial gear-up or all gear-up landings, accomplish the following: A. For airplanes, line position 002 through 803: Within 30 days of October 30, 1990 (the effective date of AD 90-19-10, Amendment 39-6743), inspect the nose and body gear selector valve installation and the wing gear selector valve installation in accordance with Boeing Service Bulletin 747-32-2361, dated September 7, 1990. 1. Prior to further flight, correct any discrepancies found in the installation, in accordance with Boeing Service Bulletin 747-32-2361, dated September 7, 1990, or Boeing Telegraphic Service Bulletin 747-32-2361, Revision 1, dated September 28, 1990. 2. Within 30 days after the effective date of this AD, for airplanes that have had discrepancies corrected in accordance with paragraph A.1. of this AD, retorque the self locking nut to 50 to 80 inch-pound, in accordance with Boeing Telegraphic Service Bulletin 747- 32-2361, Revision 1, dated September 28, 1990. B. For airplane, line position 806: Within 30 days after the effective date of this AD, inspect the nose and body gear selector valve installation and the wing gear selector valve installation in accordance with Boeing Telegraphic Service Bulletin 747-32-2361, Revision 1, dated September 28, 1990. Correct any discrepancies found in the installation prior to further flight, in accordance with Boeing Telegraphic Service Bulletin 747-32-2361, dated September 28, 1990. C. Within 10 days after completion of the inspection required by this AD, submit a report of finding any improper configuration to the FAA, Seattle Manufacturing Inspection District Office, ANM-108S, 1601 Lind Avenue S.W., Renton, Washington 98055-4056. The report must include the line number of the airplane inspected, the number of cycles, and the inspection findings. D. 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 Inspector (PI), who will either concur or comment, and then send it to the Manager, Seattle Aircraft Certification Office. E. 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 information from the manufacturer may obtain copies upon request to The Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington. Airworthiness Directive 90-23-16 supersedes AD 90-19-10, Amendment 39-6743. This amendment (39-6792, AD 90-23-16) becomes effective on November 12, 1990. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A20WE](https://openairdocs.org/tcds/A20WE): The Boeing Company; names 12 of 14 models: 747-100B Series, 747SP Series, 747-400D Series, 747-400F Series, 747-200B Series, 747-200F Series, 747-300 Series, 747-200C Series… ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 63 (63 by airframe model, 0 by engine model) - Makers: Boeing 63 Models with the most aircraft: - [Boeing 747-446](https://openairdocs.org/model/boeing-747-446): 10 aircraft (airframe model) - [Boeing 747-422](https://openairdocs.org/model/boeing-747-422): 8 aircraft (airframe model) - [Boeing 747-412](https://openairdocs.org/model/boeing-747-412): 5 aircraft (airframe model) - [Boeing 747-400F](https://openairdocs.org/model/boeing-747-400f): 4 aircraft (airframe model) - [Boeing 747-409](https://openairdocs.org/model/boeing-747-409): 4 aircraft (airframe model) - [Boeing 747-481F](https://openairdocs.org/model/boeing-747-481f): 3 aircraft (airframe model) - [Boeing 747-409F](https://openairdocs.org/model/boeing-747-409f): 3 aircraft (airframe model) - [Boeing 747-481](https://openairdocs.org/model/boeing-747-481): 3 aircraft (airframe model) - [Boeing 747-428F](https://openairdocs.org/model/boeing-747-428f): 3 aircraft (airframe model) - [Boeing 747-123](https://openairdocs.org/model/boeing-747-123): 2 aircraft (airframe model) - [Boeing 747-251F](https://openairdocs.org/model/boeing-747-251f): 2 aircraft (airframe model) - [Boeing 747-443](https://openairdocs.org/model/boeing-747-443): 2 aircraft (airframe model) - [Boeing 747-438](https://openairdocs.org/model/boeing-747-438): 2 aircraft (airframe model) - [Boeing 747-428](https://openairdocs.org/model/boeing-747-428): 2 aircraft (airframe model) - [Boeing 747-257B](https://openairdocs.org/model/boeing-747-257b): 1 aircraft (airframe model) - [Boeing 747-283B](https://openairdocs.org/model/boeing-747-283b): 1 aircraft (airframe model) - [Boeing 747-121](https://openairdocs.org/model/boeing-747-121): 1 aircraft (airframe model) - [Boeing 747-131](https://openairdocs.org/model/boeing-747-131): 1 aircraft (airframe model) - [Boeing 747-128](https://openairdocs.org/model/boeing-747-128): 1 aircraft (airframe model) - [Boeing 747-273C](https://openairdocs.org/model/boeing-747-273c): 1 aircraft (airframe model) All 24 models: https://openairdocs.org/ad/90-23-16/models.md Every aircraft: https://openairdocs.org/ad/90-23-16/aircraft.md Its text cites no advisory circulars or STCs. --- 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.