AD 98-26-08 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 DC9-53-279, Revision 01, dated May 6, 1997; 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 (g) 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 doorjamb of the forward service door, 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: The words ``repair'' and ``modify/modification'' in this AD and the referenced service bulletin are used interchangeably. (a) Prior to the accumulation of 50,000 total landings, or within 3,225 landings after the effective date of this AD, whichever occurs later, perform a one-time visual inspection to determine if the corners of the doorjamb of the forward service door have been modified prior to the effective date of this AD. (b) Group 1. If the visual inspection required by paragraph (a) of this AD reveals that the corners of the doorjamb of the forward service door 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 doorjamb of the forward service door, in accordance with McDonnell Douglas Service Bulletin DC9-53-279, dated December 10, 1996, or Revision 01, dated May 6, 1996. (1) Condition 1. If no crack is detected during any inspection required by paragraph (b) of this AD, accomplish 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 3,225 landings. (B) If the immediately preceding inspection was conducted using x-ray techniques, conduct the next inspection within 3,075 landings. (ii) Option 2. Prior to further flight, modify the corners of the doorjamb of the forward service door in accordance with the service bulletin; this modification constitutes terminating action for the repetitive inspection requirements of paragraph (b)(1)(i) of this AD. Prior to the accumulation of 28,000 landings after accomplishment of the modification, perform a high frequency eddy current (HFEC) inspection to detect cracks on the skin adjacent to the modification, in accordance with the service bulletin. Within 20,000 landings after accomplishment of the HFEC inspection, perform an eddy current inspection to detect cracks in the subject area, in accordance with the service bulletin. (A) If no crack is detected on the skin adjacent to the modification during any eddy current inspection required by paragraph (b)(1)(ii) of this AD, repeat the eddy current 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 eddy current inspection required by paragraph (b)(1)(ii) of this AD, repair it in accordance with a method approved by the Manager, Los Angeles ACO. (2) Condition 2. If any crack is found during any inspection required by paragraph (b) of this AD 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 HFEC inspection to detect cracks on the skin adjacent to the modification, in accordance with the service bulletin. Within 20,000 landings after accomplishment of the HFEC inspection, perform an eddy current inspection to detect cracks in the subject area, in accordance with the service bulletin. (i) If no crack is detected on the skin adjacent to the modification during any eddy current inspection required by paragraph (b)(2) of this AD, repeat the eddy current inspection thereafter at intervals not to exceed 20,000 landings. (ii) If any crack is detected on the skin adjacent to the modification during any eddy current inspection required by paragraph (b)(2) of this AD, repair it in accordance with a method approved by the Manager, Los Angeles ACO. (3) Condition 3. If any crack is found during any 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) Group 2, Condition 1. If the visual inspection required by paragraph (a) of this AD reveals that the corners of the doorjamb of the forward service door have been modified in accordance with the DC-9 Structural Repair Manual (SRM) (using a steel doubler), accomplish either paragraph (c)(1) or (c)(2) of this AD in accordance with McDonnell Douglas Service Bulletin DC9-53-279, dated December 10, 1996, or Revision 01, dated May 6, 1997. (1) Option 1. Prior to the accumulation of 6,000 landings after the effective date of this AD, perform a HFEC inspection to detect cracks on the skin adjacent to the modification in accordance with the service bulletin. Within 3,000 landings after accomplishment of the HFEC inspection, perform an eddy current inspection to detect cracks in the subject area, in accordance with the service bulletin. (i) If no crack is detected on the skin adjacent to the modification during any eddy current inspection required by paragraph (c)(1) of this AD, repeat the eddy current inspection thereafter at intervals not to exceed 3,000 landings. (ii) If any crack is detected on the skin adjacent to the modification during any eddy current inspection required by paragraph (c)(1) of this AD, repair it in accordance with a method approved by the Manager, Los Angeles ACO. (2) Option 2. Prior to further flight, modify the corners of the doorjamb of the forward service door in accordance with the service bulletin. Prior to the accumulation of 28,000 landings after accomplishment of the modification, perform a HFEC inspection to detect cracks on the skin adjacent to the modification, in accordance with the service bulletin. Within 20,000 landings after accomplishment of the HFEC inspection, perform an eddy current inspection to detect cracks in the subject area, in accordance with the service bulletin. (i) If no crack is detected on the skin adjacent to the modification during any eddy current inspection required by paragraph (c)(2) of this AD, repeat the eddy current inspection thereafter at intervals not to exceed 20,000 landings. (ii) If any crack is detected on the skin adjacent to the modification during any eddy current inspection required by paragraph (c)(2) of this AD, repair it in accordance with a method approved by the Manager, Los Angeles ACO. (d) Group 2, Condition 2. If the visual inspection required by paragraph (a) of this AD reveals that the corners of the doorjamb of the forward service door have been modified in accordance with DC-9 SRM or Service Rework Drawing (using an aluminum doubler), prior to the accumulation of 28,000 landings since accomplishment of the modification, or within 3,225 landings after the effective date of this AD, whichever occurs later, perform a HFEC inspection to detect cracks on the skin adjacent to the [[Page 70636]] modification, in accordance with McDonnell Douglas Service Bulletin DC9-53-279, dated December 10, 1996, or Revision 01, dated May 6, 1997. Within 20,000 landings after accomplishment of the HFEC inspection, perform an eddy current inspection to detect cracks in the subject area, in accordance with the service bulletin. (1) If no crack is detected on the skin adjacent to the modification during any eddy current inspection required by paragraph (d) of this AD, repeat the eddy current inspection thereafter at intervals not to exceed 20,000 landings. (2) If any crack is detected on the skin adjacent to the modification during any eddy current inspection required by paragraph (d) of this AD, repair it in accordance with a method approved by the Manager, Los Angeles ACO. (e) Group 2, Condition 3. If the visual inspection required by paragraph (a) of this AD reveals that the corners of the doorjamb of the forward service door have been modified, but not in accordance with the DC-9 SRM or Service Rework Drawing, prior to further flight, repair it in accordance with a method approved by the Manager, Los Angeles ACO. (f) Accomplishment of the actions required by this AD constitutes terminating action for inspections of Principal Structural Element (PSE) 53.09.033 (reference McDonnell Douglas Model DC-9 Supplemental Inspection Document) required by AD 96-13- 03, amendment 39-9671 (61 FR 31009). (g) 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. (h) 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. (i) Except as provided in paragraphs (a), (b)(1)(ii)(B), (b)(2)(ii), (b)(3), (c)(1)(ii), (c)(2)(ii), (d)(2), and (e) of this AD, the actions shall be done in accordance with McDonnell Douglas Service Bulletin DC9-53-279, dated December 10, 1996, and Revision 01, dated May 6, 1997. 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, P.O. Box 1771, Long Beach, California 90846-1771, Attention: Business Unit Manager, Contract Data Management, C1-255 (35-22). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (j) This amendment becomes effective on January 26, 1999. Issued in Renton, Washington, on December 11, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-33388 Filed 12-21-98; 8:45 am] BILLING CODE 4910-13-P