89-06-04 McDONNELL DOUGLAS: Amendment 39-6152. \n\n\tApplicability: Model DC-9-10 through -30 series and C-9 (Military) series airplanes, equipped with a non-ventral aft pressure bulkhead, certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo prevent cracks which could result in structural failure of the non-ventral aft pressure bulkhead, accomplish the following: \n\n\tA.\tPrior to the accumulation of 25,000 landings or within 500 landings after the effective date of this AD, whichever occurs later, inspect the aft pressure bulkhead attach tee section, in accordance with the following procedures. \n\n\t\t1.\tRemove any sealant from inspection area of the tee section that might hinder optically aided and high frequency eddy current inspections. Clean dirt, grease, and all foreign materials from inspection area using lint-free wipers and 1,1,1 trichloroethane solvent or equivalent; \n\n\t\t2.\tUsing optically aided visual inspection technique, inspect the 5910163-89, -93, -94, and -95 attach tees from the aft side of the bulkhead, in accordance with McDonnell Douglas Alert Service Bulletin A53-231, dated February 24, 1989 (hereinafter referred to as ASB53-231). Repeat this inspection thereafter at intervals not to exceed 1,500 landings; and \n\n\t\t3.\tUsing a high frequency eddy current inspection technique, in accordance with ASB53-231, inspect the 5910163-91 and -92 attach tees from the aft side of the bulkhead. Repeat this inspection thereafter at intervals not to exceed 500 landings. \n\n\tB.\tIf cracks are found prior to further flight, replace the cracked tee cap or repair by splicing in a section of tee cap with a new like or improved part, in accordance with McDonnell Douglas Service Rework Drawings SRO9530001, Revision C, dated August 18, 1987, and SRO9530001, Revision "Advance D", dated October 29, 1987. Prior to the accumulation of 25,000 landings after the repair or replacement, resume the repetitive inspections in accordance with paragraph A., above. \n\n\tC.\tCompliance with the requirements of this AD constitutes terminating action for the requirements of AD 88-13-09, Amendment 39-5954, relating to airplanes equipped with non-ventral aft pressure bulkheads. \n\n\tNOTE: The requirements of AD 88-13-09 relating to airplanes with ventral aft pressure bulkheads are not affected by this AD. \n\n\tD.\tAn 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, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tNOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who may add any comments then send it to the Manager, Los Angeles Aircraft Certification Office. \n\n\tE.\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes unpressurized to a base in order to comply with the requirements of this AD. \n\n\tAll persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Director of Publications, C1-LOO (54-60). These documents may be examined at FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or 3229 East Spring Street, Long Beach, California. \n\n\tThis amendment (39-6152, AD 89-06-04) becomes effective March 24, 1989.