AD 85-22-12

85-22-12 BOEING: Amendment 39-5167. Applies to all Model 747 series airplanes, through Line Number 622, certificated in any category. To prevent a condition that would lead to depressurization of the airplane, accomplish the following, unless already accomplished after August 29, 1985:

A. Within 30 days after the effective date of this AD, perform a one-time visual inspection of the aft side of the aft pressure bulkhead for evidence of repairs or damage. Damage is defined in the Structural Repair Manual.

B. Report a complete description of the findings (sketches, photos, or drawings, as necessary) of the inspections required by paragraph A., above, within 30 days after the effective date of this AD to either:

1. The Boeing Commercial Airplane Company, ATTN: Director, 747 Customer Support Engineering, P.O. Box 3707, Seattle, Washington 98124-2207; or

2. Boeing Support Engineering through the Boeing Field Service Representative.

C. If any cracking or punctures are found in the aft pressure bulkhead, repair prior to further flight in accordance with the Structural Repair Manual; Boeing Designated Engineering Representative (DER)-approved data; or data approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

D. Repair all other discrepancies or improper repairs in accordance with the Structural Repair Manual; Boeing DER-approved data; or data approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. Repairs must be performed in accordance with a schedule approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

E. Upon the request of an operator, an FAA Principal Maintenance Inspector, subject to prior approval of the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, may adjust the inspection times in this AD to permit compliance at an established inspection period of that operator, if the request contains substantiating data to justify the change for that operator.

F. Alternate means of compliance which provide an acceptable level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

G. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD.

All persons affected by this proposal who have not already received information on inspection procedures from the manufacturer may obtain copies upon request to the Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124-2207. These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.

This amendment becomes effective November 19, 1985.