AD 94-18-07

This amendment supersedes two existing airworthiness directives (AD), applicable to all McDonnell Douglas Model DC-10 series airplanes and KC-10A (military) airplanes and certain Model MD-11 series airplanes, that currently require inspections to determine the serial numbers and to detect defects in the upper and lower lock links on the nose landing gear (NLG), and rework or replacement of any defective link with a serviceable link. This amendment requires additional inspections and provides optional terminating action for those inspections. This amendment is prompted by additional reports of defects found on links that are required to be inspected by the existing AD's. The actions specified in this AD are intended to prevent collapse of the NLG.\n\n\tThe incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of September 15, 1994.\t\n\tComments for inclusion in the Rules Docket must be received on or before October 31, 1994.

Final rule; request for comments.

94-18-07 MCDONNELL DOUGLAS: Amendment 39-9020. Docket 94-NM-130-AD. Supersedes AD 94-09-01, Amendment 39-8889; and AD 94-09-17, Amendment 39-8906.\n\n\tApplicability: All Model DC-10 series airplanes and Model KC-10A (military) airplanes; and Model MD-11 series airplanes, as listed in McDonnell Douglas MD-11 Alert Service Bulletin A32-47, dated July 15, 1994; certificated in any category.\n\n\tCompliance: Required as indicated, unless accomplished previously.\n\n\tNOTE 1: Visual inspections of the lock links, as required by paragraph (a) of this AD, and eddy current inspections of the lock links, as required by paragraph (b)(1) of this AD, that have been accomplished prior to the effective date of this AD in accordance with McDonnell Douglas DC-10 Alert Service Bulletin A32-237, dated April 11, 1994; or McDonnell Douglas MD-11 Alert Service Bulletin A32-44, dated March 22, 1994, or Revision 1, dated June 16, 1994; as applicable; are considered acceptable for compliance with the applicable action specified in this amendment.\n\n\tTo prevent collapse of the nose landing gear (NLG), accomplish the following:\n\n\t(a)\tWithin 30 days after the effective date of this AD, perform a visual inspection to determine the serial number of the upper lock links, part number ACG7396-1, and the lower lock links, part number ACG7237-1, on the NLG, in accordance with McDonnell Douglas DC-10 Alert Service Bulletin A32-238, dated July 15, 1994; or McDonnell Douglas MD-11 Alert Service Bulletin A32-47, dated July 15, 1994; as applicable.\n\n\t(b)\tIf the serial number of the lock link coincides with any of the suspect serial numbers listed in McDonnell Douglas DC-10 Alert Service Bulletin A32-238, dated July 15, 1994; or McDonnell Douglas MD-11 Alert Service Bulletin A32-47, dated July 15, 1994; as applicable; accomplish paragraphs (b)(1) and (b)(2) of this AD in accordance with the alert service bulletin.\n\n\t\t(1)\tPrior to further flight, perform an eddy current inspection to detect defects in the lock link in accordance with Phase I ("Eddy Current Inspection - On Aircraft") of the Accomplishment Instructions of the applicable alert service bulletin.\n\n\t\t(2)\tPerform an expanded eddy current inspection to detect defects in the lock link, in accordance with Phase II ("Expanded Eddy Current Inspection - Off Aircraft") of the Accomplishment Instructions of the applicable alert service bulletin at the time specified in paragraph (b)(2)(i) or (b)(2)(ii) of this AD, as applicable.\n\n\t\t\t(i)\tFor Model DC-10 series airplanes and Model KC-10A airplanes: Inspect prior to the accumulation of 450 landings after the effective date of this AD, and thereafter at intervals not to exceed 450 landings.\n\n\t\t\t(ii)\tFor Model MD-11 series airplanes: Inspect prior to the accumulation of 330 landings after the effective date of this AD, and thereafter at intervals not to exceed 330 landings.\n\n\t(c)\tIf any defect is found during any inspection required by paragraph (b) of this AD, prior to further flight, accomplish either paragraph (c)(1) or (c)(2) of this AD in accordance with McDonnell Douglas DC-10 Alert Service Bulletin A32-238, dated July 15, 1994; or McDonnell Douglas MD-11 Alert Service Bulletin A32-47, dated July 15, 1994; as applicable.\n\n\t\t(1)\tRework the lock link; or\n\n\t\t(2)\tReplace the defective lock link with a serviceable lock link that has been inspected in accordance with paragraphs (a) and (b) of this AD and, if the lock link was found to contain any defect, that has been reworked in accordance with paragraph (c)(1) of this AD.\n\n\t(d)\tAccomplishment of a fluorescent penetrant inspection to detect defects of the lock links, in accordance with Phase III ("Fluorescent Penetrant Inspection - Off Aircraft") of the Accomplishment Instructions of McDonnell Douglas DC-10 Alert Service Bulletin A32-238, dated July 15, 1994; or McDonnell Douglas MD-11 Alert Service Bulletin A32-47, dated July 15, 1994; as applicable; constitutes terminating action for theinspections required by paragraph (b) of this AD.\n\n\t(e)\tIf any defect is found during an inspection performed in accordance with paragraph (d) of this AD, prior to further flight, accomplish either paragraph (e)(1) or (e)(2) of this AD in accordance with McDonnell Douglas DC-10 Alert Service Bulletin A32-238, dated July 15, 1994; or McDonnell Douglas MD-11 Alert Service Bulletin A32-47, dated July 15, 1994; as applicable.\n\n\t\t(1)\tRework the lock link; or\n\n\t\t(2)\tReplace the defective lock link with a serviceable lock link that has been inspected in accordance with paragraphs (a) and (b) of this AD and, if the lock link was found to contain any defect, that has been reworked in accordance with paragraph (e)(1) of this AD.\n\n\t(f)\tAs of the effective date of this AD, no person shall install an upper lock link, part number ACG7396-1, or a lower lock link, part number ACG7237-1, on the NLG of any airplane unless that lock link has been inspected in accordance with paragraphs (a) and (b) of this AD and reworked, as necessary, in accordance with paragraph (c)(1) or (e)(1) of this AD.\n\n\t(g)\tWithin 30 days after any defect is found during any inspection required by this AD, submit a report of inspection findings to the Manager, Los Angeles Aircraft Certification Office (ACO), 3229 East Spring Street, Long Beach, California 90806-2425; fax (310) 988-5210. The report must include a description of the defect found, the part number of the defective lock link, the serial number of the defective lock link, the number of landings on the defective lock link, and the serial number of 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(h)\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, 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.\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(i)\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(j)\tThe actions shall be done in accordance with McDonnell Douglas DC-10 Alert Service Bulletin A32-238, dated July 15, 1994; and McDonnell Douglas MD-11 Alert Service Bulletin A32-47, dated July 15, 1994. 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, P.O. Box 1771, Long Beach, California 90801-1771, Attention: Business Unit Manager, Technical Administrative Support, Dept. L51, M.C. 2-98. 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, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.\n\n\t(k)\tThis amendment becomes effective on September 15, 1994.

In April 1994, the FAA issued AD 94-09-01, amendment 39-8889 (59 FR 18722, April 20, 1994), applicable to McDonnell Douglas Model MD-11 series airplanes, and AD 94-09-17, amendment 39-8906 (59 FR 23144, May 5, 1994), applicable to McDonnell Douglas Model DC-10 series airplanes and KC-10A (military) airplanes. These AD's require inspections to determine the serial numbers and to detect defects in the upper and lower lock links on the nose landing gear (NLG), and rework or replacement of any defective link found. Both actions were prompted by a report of cracking and subsequent failure of an upper lock link on the center landing gear (CLG) on a McDonnell Douglas Model MD-11 series airplane; the cracking and failure were attributed to forging defects in the lock links.\n\n\tThe CLG lower lock links, NLG upper lock links, and NLG lower lock links are similar in design to CLG upper lock links and are manufactured by the same forging supplier; therefore, these lock links may have the same forging defects. These lock links also may be installed on Model DC-10 series airplanes and KC-10A (military) airplanes. Consequently, AD 94-09-17 was issued to address the lock links installed on Model DC-10 series airplanes and KC-10A (military) airplanes.\n\n\tFailure of the lock links on the CLG would result in collapse of the CLG; collapse of the CLG does not present an unsafe condition. Cracking and subsequent failure of the NLG lock links, if not corrected, could result in collapse of the NLG, which could reduce controllability of the airplane during takeoff or landing. The actions required by AD 94-09-01 and AD 94-09-17 are intended to prevent collapse of the NLG.\n\n\tSince the issuance of those AD's, the FAA has received reports of two additional defective lock links with three cracks that have been attributed to forging defects. These defective lock links were found on the NLG's on Model DC-10 and MD-11 series airplanes during accomplishment ofthe inspections required by the existing AD's. Subsequently, the FAA has determined that defects in the lock links may exist as a result of improperly accomplished fluorescent penetrant inspections of the entire lock link during manufacturing. After manufacture of a lock link, its material is etched and a fluorescent penetrant inspection is performed to detect forging defects. The fluorescent penetrant inspections accomplished on the affected lock links were performed without accomplishment of the etching process. Forging defects in these lock links could result in eventual failure of the lock link and subsequent collapse of the NLG.\n\n\tThe FAA has reviewed and approved McDonnell Douglas DC-10 Alert Service Bulletin A32-238 and MD-11 Alert Service Bulletin A32-47, both dated July 15, 1994, that describe procedures for visual inspections to determine the serial numbers of the upper and lower lock links on the NLG. The alert service bulletins also describe three phases of inspections:\n\n\t1.\tPhase I inspections involve an on-aircraft eddy current inspection to detect defects in the upper and lower lock links on the NLG. These inspections are designed to detect particular defects in areas of the highest probability of forging flaws.\n\n\t2.\tPhase II inspections entail expanded off-aircraft eddy current inspections to detect defects of the upper and lower lock links on the NLG. These inspections are more extensive than Phase I inspections and are designed to detect defects in an expanded area where flaws could exist.\n\n\t3.\tPhase III inspections include an off-aircraft fluorescent penetrant inspection to detect defects in the upper and lower lock links on the NLG. These inspections include etching of the link material prior to accomplishing a fluorescent penetrant inspection. Accomplishment of Phase III inspections will ensure that all forging defects are detected.\n\n\tFor NLG's on which a defective lock link is found, the alert service bulletins describe procedures for rework of the defective lock link, or replacement of the defective lock link with a serviceable lock link. Accomplishment of the fluorescent penetrant inspection and rework of any defective lock link found during that inspection, or replacement of any defective lock link found during that inspection, eliminates the need for the eddy current inspections specified in the alert service bulletins.\n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of this same type design, this AD supersedes AD 94-09-01 and AD 94-09-17 to require inspections to determine the serial numbers and to detect defects in the upper and lower lock links on the NLG, and rework of any defective lock link, or replacement of any defective lock link with a serviceable lock link. This AD also provides an optional terminating action for the required inspections. The actions are required to be accomplished in accordance with the alert service bulletins described previously.\n\n\tThis AD also requires that operators report inspection findings to the FAA in the event any defect is found during any inspection.\n\n\tThe FAA is considering further rulemaking to require accomplishment of the optional terminating action specified in this AD. However, the proposed compliance time is sufficiently long so that notice and time for public comment would not be impracticable.\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.\n\nComments Invited\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.\n\n\tComments 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.Commenters 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 94-NM-130-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."\n\nList of Subjects in 14 CFR Part 39\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.\n\nAdoption of the Amendment\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\t1.\tThe authority citation for part 39 continues to read as follows:\nAuthority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and14 CFR 11.89.\n\n§ 39.13 - (Amended)\n\t2.\tSection 39.13 is amended by removing amendments 39-8889 (59 FR 18722, April 20, 1994) and 39-8906 (59 FR 23144, May 5, 1994), and by adding a new airworthiness directive (AD), amendment 39-9020, to read as follows: