AD 95-13-11 R1

This amendment clarifies information in an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-10-10 airplanes, that currently requires repetitive inspections to detect cracking of the upper caps in the front spar of the left and right wing, and repair, if necessary. The actions specified in that AD are intended to prevent progression of fatigue cracking, which could cause reduced structural integrity of the wing front spar and damage to adjacent structures. This amendment clarifies the requirements of the current AD by revising the area of inspection. This amendment is prompted by communications received from affected operators that the current requirements of the AD are unclear.

Final rule; correction.

95-13-11 R1 MCDONNELL DOUGLAS: Amendment 39-9498. Docket 94-NM-178-AD. Revises AD 95-13-11, Amendment 39-9291.\n\n\tApplicability: Model DC-10-10 airplanes, as listed in McDonnell Douglas DC-10 Service Bulletin 57-129, dated August 12, 1994; 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 use the authority provided in paragraph (e) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.\n\n\tCompliance: Required as indicated, unless accomplished previously.\n\n\tTo prevent reduced structural integrity of the wing front spar and damage to adjacent structures due to fatigue cracking in the upper cap of the front spar of the wing, accomplish the following:\n\n\t(a)\tPrior to the accumulation of 10,000 total landings, or within 1,800 landings after the effective date of this AD, whichever occurs later, perform an initial eddy current test high frequency (ETHF) surface inspection to detect cracks in the upper cap of the front spar of the left and right wing at stations Xos 667.678 and Xos 789.645, in accordance with McDonnell Douglas DC-10 Service Bulletin 57-129, dated August 12, 1994. Repeat this inspection thereafter at the intervals specified in paragraph (b) or (c) of this AD, as applicable.\n\n\t(b)\tFor airplanes on which no crack is found: Repeat the inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 10,000 landings, or accomplish the crack preventative modification in accordance with McDonnell Douglas DC-10 Service Bulletin 57-129, dated August 12, 1994. Accomplishment of that preventative modification constitutes terminating action for the requirements of this paragraph.\n\n\t(c)\tFor airplanes on which any crack is found that is identified as "Condition II" in McDonnell Douglas DC-10 Service Bulletin 57-129, dated August 12, 1994: Accomplish paragraphs (c)(1) and (c)(2) of this AD in accordance with that service bulletin.\n\n\t\t(1)\tPrior to further flight, perform the permanent repair for cracks in accordance with the service bulletin; and\n\n\t\t(2)\tWithin 12,500 landings after the installation of the permanent repair specified in paragraph (c)(1) of this AD, perform an ETHF surface inspection for cracks, in accordance with the service bulletin. Repeat this inspection thereafter at intervals not to exceed 7,000 landings.\n\n\t(d)\tFor airplanes on which any crack is found that is identified as "Condition III" in McDonnell Douglas DC-10 Service Bulletin 57-129, dated August 12, 1994: Prior to further flight, repair the cracking in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.\n\n\t(e)\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(f)\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(g)\tThe inspections, modification, and permanent repair shall be done in accordance with McDonnell Douglas DC-10 Service Bulletin 57-129, dated August 12, 1994. This incorporation by reference was approved previously by the Director of the Federal Register, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 as of August 7, 1995 (60 FR 35326, July 7, 1995). 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, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 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(h)\tThis amendment is effective on August 7, 1995.

On June 22, 1995, the FAA issued AD 95-13-11, amendment 39-9291 (60 FR 35326, July 7, 1995), which is applicable to certain McDonnell Douglas Model DC-10-10 airplanes. That AD requires repetitive eddy current test high frequency (ETHF) surface inspections to detect fatigue cracking, and repair of the upper cap in the front spar of the wing if any cracking is found. That AD also requires additional repetitive inspections after any repair of the upper cap. Additionally, that AD stipulates that, if the preventive modification is installed on an airplane on which no cracks are found during the initial inspection, the repetitive inspections may be terminated. That action was prompted by reports of fatigue cracking in the upper cap of the front spar of the wing in the forward flange area. The actions required by that AD are intended to prevent progression of fatigue cracking, which could cause reduced structural integrity of the wing front spar and damage toadjacent structures.\n\n\tSince the issuance of that AD, the FAA has received communications from affected operators that the area defined for the ETHF surface inspection is unclear. Specifically, these operators have indicated that the referenced McDonnell Douglas DC-10 Service Bulletin 57-129, dated August 12, 1994, recommends inspection of the upper cap of the front spar of the left and right wing "between" stations Xos 667.678 and Xos 789.645 in certain paragraphs but describes the inspection "at" stations Xos 667.678 and Xos 789.645 in the accomplishment instructions. AD 95-13-11 requires inspection "between" stations Xos 667.678 and Xos 789.645.\n\n\tThese operators have therefore, requested that the FAA clarify the AD to indicate exactly what area is required to be inspected.\n\n\tIn considering this request, and upon further review of the wording of the current AD, the FAA concurs that some clarification is necessary.\n\n\tIt was the FAA's intent that the requirements of AD 95-13-11 be parallel to those actions recommended by the manufacturer in the accomplishment instructions of its referenced service bulletin. The intended requirements of the AD were that affected operators would conduct the ETHF inspections to detect fatigue cracks at the areas where cracking had been reported, namely at stations Xos 667.678 and Xos 789.645. However, as AD 95-13-11 is currently worded, operators may incorrectly conduct ETHF inspections "between" these stations, rather than "at" those stations. Such misunderstanding could result in operators unnecessarily conducting ETHF inspections at other stations, which would be of no significant safety value and would entail incurring needless additional costs in labor and downtime.\n\n\tOperators should note that the economic information supplied in the preamble of AD 95-13-11 remains unchanged since that information was based on the workhours required to perform the ETHF inspection at stations Xos 667.678 and Xos 789.645, in accordance with data supplied in McDonnell Douglas Service Bulletin 57-129, dated August 12, 1994.\n\n\tSince it is obvious that the required ETHF inspection area is not totally clear in the way that AD 95-13-11 is currently worded, the FAA has determined that the wording of paragraph (a) of the AD must be revised to clarify the intent of the required actions. This action revises that paragraph to specify that the inspection area is at stations Xos 667.678 and Xos 789.645.\n\n\tAction is taken herein to clarify these requirements of AD 95-13-11 and to correctly add the AD as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13).\n\n\tThe final rule is being reprinted in its entirety for the convenience of affected operators. The effective date remains August 7, 1995.\n\n\tSince this action only clarifies a current requirement, it has no adverse economic impact and imposes no additional burden on any person. Therefore, notice and public procedures hereon are unnecessary.\n\nList of Subjects in 14 CFR Part 39\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.\n\nAdoption of the Correction\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 USC 106(g), 40113, 44701. \n\n§ 39.13 - (Amended)\n\n\t2. Section 39.13 is amended by removing amendment 39-9291 (60 FR 35326, July 7, 1995), and by adding a new airworthiness directive (AD), amendment 39-9498, to read as follows: