AD 89-25-03

89-25-03 MCDONNELL DOUGLAS: Amendment 39-6408. Docket No. 89-NM-228-AD.

Applicability: Model DC-9-10, -20, -30, -40, -50, -81, -82 and C-9 (Military) series airplanes, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent crack propagation, which could result in rapid cabin depressurization, accomplish the following:

A. For airplanes fuselage numbers 1 through 950: Prior to the occurrence of the latest of the compliance times set forth below, inspect the left- and right-hand window belt panels and adjacent structure for cracks using eddy current methods, in accordance with McDonnell Douglas Alert Service Bulletin (ASB) A53-142, Revision 8, dated October 25, 1989 (hereinafter referred to as ASB 53-142):

1. Prior to the accumulation of 30,000 or more landings; or

2. Within 2,500 landings since the last inspection in accordance with Amendment 39-5136, AD 85-19-02; or

3. Within 500 landingsafter the effective date of this AD.

B. For airplanes, fuselage numbers 951 through 1157: Prior to the occurrence of the latest of the compliance times set forth below, inspect the left- and right-hand window belt panels and adjacent structure for cracks using eddy current methods, in accordance with McDonnell Douglas ASB A53-142:

1. Prior to the accumulation of 30,000 or more landings; or

2. Within 10,000 landings since the last inspection in accordance with Amendment 39-5136, AD 85-19-02; or

3. Within 500 landings after the effective date of this AD.

C. Repeat the inspections required by paragraph A. of this AD at intervals not to exceed 800 landings, until such time as the preventive modification is installed in accordance with McDonnell Douglas Service Bulletin 53-142, dated June 30, 1983.

D. Repeat the inspections required by paragraph B. of this AD at intervals not to exceed 20,000 landings, until such time as preventive modification is installedin accordance with McDonnell Douglas Service Bulletin 53-142, dated June 30, 1983.

E. Credit may be given for inspections and repairs already accomplished in accordance with earlier versions of the McDonnell Douglas ASB A53-142.

F. If any fuselage skin cracks are found, accomplish the procedures described in paragraphs F.1., F.2., or F.3., below:

1. Before further flight, repair fuselage skin cracks in accordance with Option 2 described in ASB A53-142; or

2. Before further flight, repair fuselage skin cracks in accordance with McDonnell Douglas DC-9 Drawing J060131. Repairs of fuselage skin cracks accomplished in accordance with Drawing J060131 must be visually inspected at intervals not to exceed 2,000 landings, and must be replaced by repairs accomplished in accordance with McDonnell Douglas Drawing J060109 within 4,000 landings. After accomplishment of repairs in accordance with Drawing J060109, inspect the unrepaired areas of the airplane in accordance withthe requirements of paragraphs C., above, for fuselages 1 through 950, or paragraph D., above, for fuselages 951 through 1157 or

3. Before further flight, install a placard in plain view of the pilot reading "Pressurized Flight Prohibited," and accomplish either paragraph F.1. or F.2., above, within 4,000 landings.

G. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes unpressurized to a base to comply with the requirements of this AD.

H. 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, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region.

NOTE: 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, FAA, Northwest Mountain Region.

All persons affected by this directive who have not already received the appropriate service information from the manufacturer may obtain copies upon request to McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846. This information 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.

This AD supersedes Amendment 39-5136, AD 85-19-02, which became effective on October 12, 1985.

This amendment (39-6408, AD 89-25-03) becomes effective on December 18, 1989.