AD 98-08-24 Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, - 30, -40, and -50 Series Airplanes, and C-9 (Military) Airplanes

Models named: DC-9-10, -20, -30, -40, -50 series. Read the applicability below — it usually turns on serial or part numbers too.

Model DC-9-10, -20, -30, -40, and -50 series airplanes, and C-9 (military) airplanes, as listed in McDonnell Douglas Service Bulletin DC9-53-277, dated September 30, 1996; certificated in any category. Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Required as indicated, unless accomplished previously. To detect and correct fatigue cracking in the fuselage skin or doubler at the corners of the forward lower cargo doorjamb, which could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane, accomplish the following: Note 2: Where there are differences between the service bulletin and the AD, the AD prevails. Note 3: This AD is related to AD 96-13-03, amendment 39-9671, (61 FR 31009, June 19, 1996), and will affect Principal Structural Element (PSE) 53.09.001 of the DC-9 Supplemental Inspection Document (SID). (a) Prior to the accumulation of 48,000 total landings, or within 3,500 landings after the effective date of this AD, whichever occurs later, perform a one-time visual inspection to determine if the corners of the forward lower cargo doorjamb have been modified prior to the effective date of this AD. (b) If the visual inspection required by paragraph (a) of this AD reveals that the corners of the forward lower cargo doorjamb have not been modified, prior to further flight, perform a low frequency eddy current (LFEC) or x-ray inspection to detect cracks of the fuselage skin and doubler at all corners of the forward lower cargo doorjamb, in accordance with McDonnell Douglas Service Bulletin DC9- 53-277, dated September 30, 1996. (1) If no crack is detected during the LFEC or x-ray inspection required by this paragraph, accomplish the requirements of either paragraph (b)(1)(i) or (b)(1)(ii) of this AD. (i) Option 1. Repeat the inspections as follows until paragraph (b)(1)(ii) of this AD is accomplished: (A) If the immediately preceding inspection was conducted using LFEC techniques, conduct the next inspection within 3,500 landings. (B) If the immediately preceding inspection was conducted using x-ray techniques, conduct the next inspection within 2,850 landings. (ii) Option 2. Prior to further flight, modify the corners of the forward lower cargo doorjamb, in accordance with the service bulletin. Prior to the accumulation of 28,000 landings after accomplishment of that modification, perform a LFEC inspection to detect cracks on the skin adjacent to the modification, in accordance with the service bulletin. Repeat the LFEC inspection thereafter at intervals not to exceed 20,000 landings. (A) If no crack is detected on the skin adjacent to the modification during any LFEC or x-ray inspection required by this paragraph, repeat the LFEC inspection thereafter at intervals not to exceed 20,000 landings. (B) If any crack is detected on the skin adjacent to the modification during any LFEC or x-ray inspection required by this paragraph, prior to further flight, repair it in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. (2) If any crack is found during any LFEC or x-ray inspection required by this paragraph and the crack is 2 inches or less in length: Prior to further flight, modify it in accordance with the service bulletin. Prior to the accumulation of 28,000 landings after accomplishment of the modification, perform a LFEC inspection to detect cracks on the skin adjacent to the modification, in accordance with the service bulletin. (i) If no crack is detected during the LFEC inspection required by this paragraph, repeat the LFEC inspection thereafter at intervals not to exceed 20,000 landings. (ii) If any crack is detected during the LFEC inspection required by this paragraph, prior to further flight, repair it in accordance with a method approved by the Manager, Los Angeles ACO. (3) If any crack is found during any LFEC or x-ray inspection required by this paragraph and the crack is greater than 2 inches in length: Prior to further flight, repair it in accordance with a method approved by the Manager, Los Angeles ACO. (c) If the visual inspection required by paragraph (a) of this AD reveals that the corners of the forward lower cargo doorjamb have been modified, but not in accordance with the DC-9 Structural Repair Manual (SRM) or Service Rework Drawing, prior to further flight, repair it in accordance with a method approved by the Manager, Los Angeles ACO. (d) If the visual inspection required by paragraph (a) of this AD reveals that the corners of the forward lower cargo doorjamb have been modified in accordance with DC-9 SRM or Service Rework Drawing, prior to the accumulation of 28,000 landings since accomplishment of that modification, or within 3,500 landings after the effective date of this AD, whichever occurs later, perform a LFEC inspection to detect cracks on the skin adjacent to the modification, in accordance with McDonnell Douglas Service Bulletin DC9-53-277, dated September 30, 1996. Repeat the LFEC inspection thereafter at intervals not to exceed 20,000 landings. (1) If no crack is detected during any LFEC inspection required by this paragraph, repeat the LFEC inspection thereafter at intervals not to exceed 20,000 landings. (2) If any crack is detected during any LFEC inspection required by this paragraph, prior to further flight, repair it in accordance with a method approved by the Manager, Los Angeles ACO. (e) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO. Note 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. (f) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. (g) Except as provided by paragraphs (a), (b)(1)(ii)(B), (b)(2)(ii), (b)(3), (c), and (d)(2) of this AD, the actions shall be done in accordance with McDonnell Douglas Service Bulletin DC9-53- 277, dated September 30, 1996. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from The Boeing Company, Douglas Products Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Dept. C1-L51 (2-60). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (h) This amendment becomes effective on May 22, 1998. Issued in Renton, Washington, on April 9, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-10056 Filed 4-16-98; 8:45 am] BILLING CODE 4910-13-U