AD 90-23-16

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.