90-07-06 MCDONNELL DOUGLAS: Amendment 39-6551. Docket No. 89-NM-204-AD. \n\n\tApplicability: Model DC-9-10, -20, and -30 series airplanes, equipped with a non-ventral aft pressure bulkhead; as listed in McDonnell Douglas Service Bulletin 52-167, dated August 31, 1989; operating in a passenger or passenger/cargo configuration; certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tNOTE: The requirements of this AD become applicable at the time an all-cargo configuration is converted to a passenger or passenger/cargo configuration. \n\n\tTo prevent delayed passenger evacuation through the aft pressure bulkhead emergency exit during an emergency evacuation, accomplish the following: \n\n\tA.\tWithin three months after the effective date of this AD, install a placard with exit opening instructions, in accordance with the Accomplishment Instructions of McDonnell Douglas Service Bulletin 52-167, dated August 31, 1989. \n\n\tB.\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\t\tNOTE: 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, Los Angeles Aircraft Certification Office. \n\n\tC.\tSpecial 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. \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 90801, ATTN: Director of Publications, C1-L00 (54-60). These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California. \n\n\tThis amendment (39-6551, AD 90-07-06) becomes effective on April 30, 1990.