AD 95-21-11

This amendment adopts a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-10-10, -15, -30, -40, and KC-10 (military) series airplanes. This action requires inspections to detect cracking of the wing pylon aft bulkheads and upper spar webs, and replacement or repair, if necessary. This amendment is prompted by reports of fatigue cracking in the aft bulkhead and upper spar webs. The actions specified in this AD are intended to prevent failure of the wing pylon aft bulkhead due to fatigue cracking; such failure could lead to separation of the engine and pylon from the airplane.

Final rule; request for comments.

95-21-11 MCDONNELL DOUGLAS: Amendment 39-9397. Docket 95-NM-181-AD. \n\n\tApplicability: Model DC-10-10, -15, -30, -40, and KC-10 (military) series airplanes; as listed in McDonnell Douglas DC-10 Alert Service Bulletin A54-106, Revision 2, dated November 3, 1994; certificated in any category; on which neither of the following actions have been accomplished: \n\n\tthe initial eddy current inspections (required by paragraph (a) of AD 95-11-11 R1 (amendment 39-9315)), as described in Phase II of McDonnell Douglas DC-10 Alert Service Bulletin A54-106, Revision 2, dated November 3, 1994. \n\n\tthe gap inspection and shimming (specified in paragraph (c) of AD 95-11-11 R1 (amendment 39-9315)), as described in Phase III of McDonnell Douglas DC-10 Alert Service Bulletin A54-106, Revision 2, dated November 3, 1994. \n\n\tNOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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\tNOTE 2: Compliance with AD 92-17-13, amendment 39-8342 (57 FR 36894, August 7, 1992) does not constitute compliance with this AD. \n\n\tTo prevent failure of the wing pylon aft bulkhead due to fatigue cracking, which could lead to separation of the engine and pylon from the airplane, accomplish the following: \n\n\t(a)\tWithin 30 days after the effective date of this AD, accomplish the actions required by paragraphs (a)(1) and (a)(2) of this AD in accordance with McDonnell Douglas DC-10 Alert Service Bulletin A54-106, Revision 2, dated November 3, 1994, and McDonnell Douglas ROD Sketch 95-09-14-005, dated September 14, 1995. \n\n\t\t(1)\tFirst, conduct a visual inspection using bright light, mirrors, and appropriate optical aids to detect cracks of the left and right wing pylon aft bulkhead and the upper spar web, in accordance with the instructions in Phase I, paragraphs D.(1), D.(2), D.(3), D.(4), and D.(5), of the alert service bulletin. The ROD sketch must be used to supplement the inspection instructions contained in the alert service bulletin. And \n\n\t\t(2)\tSecond, immediately subsequent to accomplishing the inspection required by paragraph (a)(1) of this AD, conduct a visual inspection, using the aid of either a flexible borescope or a rigid borescope with a 90-degree field of view, to detect cracks of the left and right wing pylon aft bulkhead in accordance with the instructions in Phase I, paragraphs D.(2) and D.(3), of the alert service bulletin. The ROD sketch must be used to supplement the inspection instructions contained in the alert service bulletin. \n\n\t(b)\tIf any cracking is detected in the wing pylon aft bulkhead during any inspection required by this AD, prior to further flight, remove and replace the cracked bulkhead in accordance with McDonnell Douglas DC-10 Alert Service Bulletin A54-106, Revision 2, dated November 3, 1994. \n\n\t(c)\tIf any cracking is detected in the upper spar web during any inspection required by this AD, prior to further flight, repair in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. \n\n\t(d)\tIf any cracking is detected during any inspection required by this AD, within 10 days after detection submit a report of the inspection findings to the FAA, Transport Airplane Directorate, Los Angeles ACO, Attention: Maureen Moreland (ANM-120L), 3960 Paramount Boulevard, Lakewood, California 90712; fax (310) 627-5210. The report shall include the airplane serial number, a sketch or photograph of the cracking, a description of the cracking, and the number of total landings and hours time-in-service on the airplane. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056. \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 3: 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 actions shall be done in accordance with McDonnell Douglas ROD Sketch 95-09- 14-005, dated September 14, 1995, and McDonnell Douglas DC-10 Alert Service Bulletin A54- 106, Revision 2, dated November 3, 1994. The incorporation by reference of McDonnell Douglas ROD Sketch 95-09-14-005, dated September 14, 1995, was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. The incorporation by reference of McDonnell Douglas DC-10 Alert Service Bulletin A54-106, Revision 2, dated November 3, 1994, 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 July 3, 1995 (60 FR 28524, June 1, 1995). Copies of the ROD sketch may be obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Customer Services Airframe, Department C1-L32 (35-35); telephone: (310) 593-8114. Copies of the alert service bulletin 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 becomes effective on November 2, 1995.

On July 24, 1992, the FAA issued AD 92-17-13, amendment 39-8342 (57 FR 36894, August 17, 1992), which is applicable to all McDonnell Douglas Model DC- 10 series airplanes. That AD requires a one-time visual inspection to detect cracks of the wing pylon aft bulkheads and upper spar webs, and repair, if necessary. Additionally, it requires that operators submit a report of inspection findings to the FAA. That AD was prompted by reports of fatigue cracking that occurred in the wing pylon aft bulkheads on two airplanes. The fatigue cracking initiated at fastener holes and/or at the lower forward edge of the bulkhead flange. Such fatigue cracking, if not detected and corrected in a timely manner, could lead to failure of the wing pylon aft bulkhead and subsequent separation of the engine and pylon from the airplane. \n\n\tOne of the intended purposes of the one-time visual inspection and submission of reports required by that AD was to allow the FAA and the manufacturer to obtain data as to the general condition of the affected fleet relative to the identified fatigue cracking. Subsequent to the issuance of that AD, the manufacturer has conducted further investigation and analysis of the fatigue cracking found in the subject areas. This effort revealed that the cracking was caused by fatigue, which was accelerated by preload conditions. The manufacturer developed inspection procedures to ensure that this fatigue cracking is identified and corrected before it reaches critical lengths. \n\n\tSubsequently, on May 19, 1995, the FAA issued AD 95-11-11, amendment 39-9244 (60 FR 28524, June 1, 1995), which is applicable to certain McDonnell Douglas Model DC-10 series airplanes. A correction of the rule, AD 95-11-11 R1, amendment 39-9315, was published in the Federal Register on July 24, 1995 (60 FR 37821). That AD was issued to address the preload conditions discussed previously. That AD requires repetitive eddy current inspections to detectfatigue cracking of the pylon aft bulkhead flange, upper pylon box web, fitting radius, and adjacent tangent areas; and repair, if necessary. The initial inspection is required to be accomplished prior to the accumulation of 1,800 landings after July 3, 1995. \n\n\tSince the issuance of those two AD's, the FAA has received a report indicating that fatigue cracking in the aft bulkhead on the no. 1 pylon had propagated through the upper forward flange and continued down the vertical web of the bulkhead for approximately 11 inches. In light of this report, the FAA has determined that additional measures must be taken to ensure that any fatigue cracking in the aft bulkhead is detected in a timely manner. \n\n\tThe FAA previously reviewed and approved McDonnell Douglas DC-10 Alert Service Bulletin, A54-106, Revision 2, dated November 3, 1994, which describes procedures for a one-time visual inspection to detect fatigue cracking of the wing pylon aft bulkhead and upper spar web, and replacement of any cracked bulkhead. This alert service bulletin also describes procedures for conducting repetitive eddy current inspections of this area (specified as "Phase II"), and for conducting a gap inspection of certain areas and necessary shimming (referred to as "Phase III"). \n\n\tThe FAA also has reviewed and approved McDonnell Douglas ROD Sketch 95-09-14-005, dated September 14, 1995, which supplements the inspection procedures described in McDonnell Douglas DC-10 Alert Service Bulletin A54-106. \n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other McDonnell Douglas DC-10-10, -15, -30, -40, and KC-10 (military) series airplanes of the same type design, this AD is being issued to prevent separation of the engine and pylon from the airplane due to failure of the wing pylon aft bulkhead caused by fatigue cracking. This AD applies only to those airplanes on which neither the previously required eddy current inspections required by AD 95-11-11 R1 have been performed, nor the gap inspection and shimming specified in paragraph (c) of AD 95-11-11 R1 have been performed. This AD requires a one-time visual inspection to detect fatigue cracking of the wing pylon aft bulkhead and upper spar web, replacement of any cracked bulkhead, and repair of any cracked upper spar web. Additionally, this AD requires that certain portions of the visual inspection be accomplished with the aid of a borescope. These actions are required to be accomplished in accordance with the alert service bulletin and the ROD sketch described previously. Any necessary repair is required to be accomplished in accordance with a method approved by the FAA. \n\n\tFor airplanes on which cracking is found during the required inspections, this AD requires that operators report results of those inspection findings to the FAA. \n\n\tSince a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. Comments Invited \n\n\tAlthough this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. \n\n\tCommenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 95-NM-181-AD." The postcard will be date stamped and returned to the commenter. \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\tThe FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List 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: Authority: 49 USC 106(g), 40101, 40113, 44701. \n\n§ 39.13 - (Amended) \n\n\t2. Section 39.13 is amended by adding the following new airworthiness directive: