AD 96-24-15

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-10 series airplanes, and KC-10A (military) series airplanes, that requires high frequency eddy current inspections to detect cracks in the secondary pivot support of the horizontal stabilizer, and various follow-on actions, if necessary. This amendment is prompted by reports of crack development in the secondary pivot support of the horizontal stabilizer due to fatigue. The actions specified by this AD are intended to prevent such fatigue cracking, which could result in reduced structural integrity of the horizontal stabilizer and, consequently, lead to reduced controllability of the airplane.

Final rule.

96-24-15 MCDONNELL DOUGLAS: Amendment 39-9839. Docket 95-NM-199-AD. \n\n\tApplicability: Model DC-10-10, -15, -30, and -40 series airplanes, and KC-10A (military) airplanes; as listed in McDonnell Douglas DC-10 Service Bulletin 53-167, Revision 1, dated February 15, 1995; certificated in any category. \n\n\tNOTE 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 (d) 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. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent fatigue cracking in the secondary pivot support of the horizontal stabilizer, which could result in reduced structural integrity of the horizontal stabilizer and, consequently, lead to reduced controllability of the airplane, accomplish the following: \n\n\t(a)\tPrior to the accumulation of 10,000 total landings, or within 3,000 landings after the effective date of this AD, whichever occurs later, perform a high frequency eddy current (HFEC) inspection to detect cracks in the secondary pivot support of the horizontal stabilizer, in accordance with McDonnell Douglas DC-10 Service Bulletin 53-167, Revision 1, dated February 15, 1995. \n\n\t(b)\tIf no cracks are detected during the HFEC inspection required by paragraph (a) of this AD, accomplish paragraph (b)(1) of this AD until paragraph (b)(2) of this AD is accomplished. \n\n\t\t(1)\tRepeat the HFEC inspectionthereafter at intervals not to exceed 10,000 landings. \n\n\t\t(2)\tAccomplishment of the preventative modification in accordance with Condition I (no cracks), Option 2, of the service bulletin constitutes terminating action for the repetitive inspection requirements of paragraph (b)(1) of this AD. \n\n\t(c)\tIf any crack is detected during the HFEC inspection required by paragraph (a) or (b) of this AD, prior to further flight, accomplish either paragraph (c)(1) or (c)(2) of this AD. \n\n\t\t(1)\tRepair the crack in accordance with Paragraph (1) of Condition II (cracks), Option 1 (temporary repair), of the Accomplishment Instructions of the service bulletin. Within 300 landings after accomplishing that repair, perform a visual inspection to detect cracks at the area of the repair, in accordance with the service bulletin. Repeat the visual inspection thereafter at intervals not to exceed 300 landings. \n\n\t\t\t(i)\tIf any crack is detected during the visual inspection required by paragraph (c)(1) of this AD, 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. \n\n\t\t\t(ii)\tPrior to 2,800 landings after accomplishing the HFEC inspection required by paragraph (a) of this AD, replace the secondary pivot support of the horizontal stabilizer with a new secondary pivot support, in accordance with Condition II (cracks), Option 2, of the service bulletin. Accomplishment of this replacement constitutes terminating action for the repetitive HFEC and visual inspection requirements of this AD. \n\n\t\t(2)\tReplace the secondary pivot support of the horizontal stabilizer with a new secondary pivot support, in accordance with Condition II (cracks), Option 2 (permanent repair), of the service bulletin. Accomplishment of this replacement constitutes terminating action for the repetitive HFEC and visual inspection requirements of this AD. \n\n\t(d)\tAn 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 ACO. 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. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. \n\n\t(e)\tSpecial 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. \n\n\t(f)\tThe inspections, certain repairs, and replacement shall be done in accordance with McDonnell Douglas DC-10 Service Bulletin 53-167, Revision 1, dated February 15, 1995. 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 McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Department C1-L51 (2-60). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, 3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(g)\tThis amendment becomes effective on January 27, 1997.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-10 series airplanes, and KC-10A (military) airplanes was published as a supplemental notice of proposed rulemaking (NPRM) in the Federal Register on March 22, 1996 (61 FR 11789). That action proposed to require high frequency eddy current inspections to detect cracks in the secondary pivot support of the horizontal stabilizer. That action also proposed to require repair of the cracked area and follow-on actions; or replacement of the cracked secondary pivot support of the horizontal stabilizer with a new secondary pivot support, which would constitute terminating action for the repetitive inspections. \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. \n\nSupport for the Proposal \n\n\tOne commenter supports the proposal. \n\nRequest that Credit Be Given for Previous Inspections \n\n\tOne commenter states that the proposed inspections already have been accomplished on a number of affected airplanes. Because of this, the commenter requests that the proposed rule be revised to specify that those operators will be given "credit" for having previously accomplished what the proposed rule would require. \n\n\tThe FAA does not consider that a change to the final rule is necessary. Operators are always given credit for work previously performed by means of the phrase in the "Compliance" section of the AD that states, "Required as indicated, unless accomplished previously." Therefore, in the case of this AD, if the initial inspection has been accomplished prior to the effective date of the AD, this AD does not require that it be repeated. However, the AD does require that repetitive inspections be conducted thereafter at intervals not to exceed 10,000 landings (if no cracking is detected, as specified in paragraph (b)(1)), and that the other follow-on actions be accomplished when indicated.\n\nConclusion \n\n\tAfter careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\nCost Impact \n\n\tThere are approximately 376 McDonnell Douglas Model DC-10 series airplanes and KC-10A (military) airplanes of the affected design in the worldwide fleet. The FAA estimates that 230 airplanes of U.S. registry will be affected by this AD, that it will take approximately 5 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $69,000, or $300 per airplane, per inspection cycle. \n\n\tThe cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. \n\nRegulatory Impact \n\n\tThe regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. \n\n\tFor the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria ofthe Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\n\tAccordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: \n\nPART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: \n\nAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 - (Amended) \n\n\t2. Section 39.13 is amended by adding the following new airworthiness directive: