[Federal Register Volume 61, Number 70 (Wednesday, April 10, 1996)] [Proposed Rules] [Pages 15904-15906] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 96-8917] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION 14 CFR Part 39 [Docket No. 96-NM-39-AD] Airworthiness Directives; McDonnell Douglas Model DC-10-10 and DC-10-15 Series Airplanes AGENCY: Federal Aviation Administration, DOT. ACTION: Notice of proposed rulemaking (NPRM). ----------------------------------------------------------------------- SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-10-10 and DC-10-15 series airplanes. This proposal would require an inspection for evidence of missing chrome and for corrosion on the chrome surfaces, or verification that the forward trunnion bolts have been chrome plated in a specific manner; and rework or replacement of the bolts, if necessary. This proposal is prompted by a report of chrome flaking on the bearing surface of the trunnion bolts due to improper cleaning of the base material prior to chrome plating. The actions specified by the proposed AD are intended to prevent premature failure of the trunnion bolts and subsequent collapse of the main landing gear (MLG) as a result of chrome flaking and severe corrosion on the bearing surface and in the mechanical fuse. DATES: Comments must be received by June 4, 1996. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 96-NM-39-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. The service information referenced in the proposed rule may be obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Department C1-L51 (2-60). This information may be examined 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. FOR FURTHER INFORMATION CONTACT: Maureen Moreland or Ron Atmur, Aerospace Engineers, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone (310) 627-5238 or (310) 627-5224; fax (310) 627-5210. SUPPLEMENTARY INFORMATION: Comments Invited Interested persons are invited to participate in the making of the proposed 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 [[Page 15905]] specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 96-NM-39-AD.'' The postcard will be date stamped and returned to the commenter. Availability of NPRMs Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 96-NM-39-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion On January 23, 1996, the FAA issued AD 96-03-05, amendment 39-9502 (61 FR 5281, February 12, 1996), which is applicable to certain McDonnell Douglas Model MD-11 series airplanes and Model DC-10-30, DC- 10-40, and KC-10A (military) airplanes. For Model MD-11 series airplanes, that AD requires an inspection to determine the serial number of the forward trunnion bolts on the main landing gear (MLG), and rework or replacement of the bolts, if necessary. For Model DC-10- 30, DC-10-40, and KC-10A (military) airplanes, that AD requires an inspection for evidence of missing chrome and for corrosion on the chrome surfaces, or verification that the forward trunnion bolts have been chrome plated in a specific manner; and rework or replacement of the bolts, if necessary. That AD was prompted by reports of chrome flaking on the bearing surface of the trunnion bolts due to improper cleaning of the base material prior to chrome plating. The actions specified by that AD are intended to prevent premature failure of the trunnion bolts and subsequent collapse of the MLG as a result of severe corrosion on the bearing surface and in the mechanical fuse due to chrome flaking. Since the issuance of AD 96-03-05, the FAA has received reports indicating that the trunnion bolts on certain Model DC-10-10 and DC-10- 15 series airplanes were chrome plated during the same time frame using the same process as the trunnion bolts installed on airplanes affected by AD 96-03-05. Additionally, the FAA has received a report of chrome flaking on the bearing surface of the trunnion bolt installed on the MLG of a Model DC-10-10 series airplane. Subsequently, the FAA has reviewed and approved McDonnell Douglas Service Bulletin DC10-32-241, dated December 13, 1995, which describes procedures for a visual inspection for evidence of missing chrome and for corrosion on the chrome surfaces of the trunnion bolts, or verification that the forward trunnion bolts have been chrome plated in a specific manner. The service bulletin also provides procedures for certain rework or replacement of the bolts with serviceable parts, if necessary. Accomplishment of the rework or replacement will minimize the possibility of chrome flaking on the forward trunnion bolts. Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require a visual inspection for evidence of missing chrome and for corrosion on the chrome surfaces, or verification that the forward trunnion bolts have been chrome plated in a specific manner; and rework or replacement of the bolts, if necessary. The inspection, verification, and certain corrective actions would be required to be accomplished in accordance with the service bulletin described previously. A portion of the rework would be required to be accomplished in accordance with the Component Maintenance Manual or a method approved by the FAA. There are approximately 139 McDonnell Douglas Model DC-10-10 and DC-10-15 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 121 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per airplane to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $7,260, or $60 per airplane. The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this proposed regulation (1) is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Safety. The Proposed Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39--AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. Sec. 39.13 [Amended] 2. Section 39.13 is amended by adding the following new airworthiness directive: McDonnell Douglas: Docket 96-NM-39-AD. Applicability: Model DC-10-10 and DC-10-15 series airplanes, as listed in McDonnell Douglas Service Bulletin DC10-32-241, dated December 13, 1995; 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 [[Page 15906]] 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 (c) 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. Compliance: Required as indicated, unless accomplished previously. To prevent premature failure of the trunnion bolts and subsequent collapse of the main landing gear (MLG), accomplish the following: (a) For airplanes on which the forward trunnion bolts, part number (P/N) ARG7557-501, installed on the left and right MLG's, have accumulated 6,000 or more total flight hours, or 2,000 or more total flight cycles, as of the date of the inspection or verification required by paragraph (a)(1) or (a)(2), respectively, of this AD: Within 18 months after the effective date of this AD, accomplish either paragraph (a)(1) or (a)(2) of this AD, in accordance with McDonnell Douglas Service Bulletin DC10-32-241, dated December 13, 1995. (1) Remove the bolts and perform a visual inspection for evidence of missing chrome and for corrosion on the chrome surfaces, in accordance with the service bulletin. (i) If no evidence of missing chrome and no corrosion on the chrome surfaces are found, no further action is required by this AD. (ii) If any evidence of missing chrome or any corrosion on the chrome surfaces is found, prior to further flight, accomplish either paragraph (a)(1)(ii)(A) or (a)(1)(ii)(B) of this AD. (A) Remove the chrome plating on the trunnion bolt in accordance with the service bulletin; replace the plating in accordance with the Component Maintenance Manual (CMM), Chapter 20-10-02, Revision 31, dated September 1, 1991, or in accordance with a method approved by a McDonnell Douglas Designated Engineering Representative (DER) who has been given a special delegation by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate, to make such a finding; and reinstall the reworked bolt in accordance with the service bulletin. (B) Replace the trunnion bolt with a serviceable part in accordance with the service bulletin. (2) Verify whether the forward trunnion bolts, P/N ARG7557-501, installed on the left and right MLG's, have been chrome plated since original manufacture, in accordance with the CMM, Chapter 20-10-02, Revision 31, dated September 1, 1991, or in accordance with a method approved by a McDonnell Douglas DER who has been given a special delegation by the Manager, Los Angeles ACO, to make such a finding. (i) If the bolts have been chrome plated since original manufacture, in accordance with the CMM, Chapter 20-10-02, Revision 31, dated September 1, 1991, or in accordance with a method approved by a McDonnell Douglas DER who has been given a special delegation by the Manager, Los Angeles ACO, to make such a finding: No further action is required by this AD. (ii) If any bolt has not been chrome plated since original manufacture, in accordance with the CMM, Chapter 20-10-02, Revision 31, dated September 1, 1991, or in accordance with a method approved by a McDonnell Douglas DER who has been given a special delegation by the Manager, Los Angeles ACO, to make such a finding: Prior to further flight, accomplish the requirements of either paragraph (a)(1)(ii)(A) or (a)(1)(ii)(B) of this AD in accordance with the service bulletin. (b) For airplanes other than those identified in paragraph (a) of this AD: Within 18 months after the effective date of this AD, verify whether the forward trunnion bolts, P/N ARG7557-501, installed on the left and right MLG's, have been chrome plated since original manufacture, in accordance with the CMM, Chapter 20-10-02, Revision 31, dated September 1, 1991, or in accordance with a method approved by a McDonnell Douglas DER who has been given a special delegation by the Manager, Los Angeles ACO, to make such a finding. (1) If the bolts have been chrome plated since original manufacture, in accordance with the CMM, Chapter 20-10-02, Revision 31, dated September 1, 1991, or in accordance with a method approved by a McDonnell Douglas DER who has been given a special delegation by the Manager, Los Angeles ACO, to make such a finding: No further action is required by this AD. (2) If any bolt has not been chrome plated since original manufacture, in accordance with the CMM, Chapter 20-10-02, Revision 31, dated September 1, 1991, or in accordance with a method approved by a McDonnell Douglas DER who has been given a special delegation by the Manager, Los Angeles ACO, to make such a finding: Prior to further flight, accomplish the requirements of either paragraph (b)(2)(i) or (b)(2)(ii) of this AD in accordance with McDonnell Douglas Service Bulletin DC10-32-241, dated December 13, 1995. (i) Remove the chrome plating on the trunnion bolt in accordance with the service bulletin; replace the plating in accordance with the Component Maintenance Manual (CMM), Chapter 20-10-02, Revision 31, dated September 1, 1991, or in accordance with a method approved by a McDonnell Douglas Designated Engineering Representative (DER) who has been given a special delegation by the Manager, Los Angeles ACO, FAA, Transport Airplane Directorate, to make such a finding; and reinstall the reworked bolt in accordance with the service bulletin. Or (ii) Replace the trunnion bolt with a serviceable part in accordance with the service bulletin. (c) 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 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. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. (d) 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. Issued in Renton, Washington, on April 4, 1996. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 96-8917 Filed 4-9-96; 8:45 am] BILLING CODE 4910-13-P