[Federal Register Volume 63, Number 14 (Thursday, January 22, 1998)] [Proposed Rules] [Pages 3267-3270] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-1427] ======================================================================= ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 97-NM-14-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas Model DC-10-10, -30, and -40 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, -30, and -40 series airplanes. This proposal would require replacement of certain taper-lok attachments and forward trunnion bolts with new components that attach the left and right main landing gear (MLG) to each wing. This proposal is prompted by a report indicating that, due to overstrength of the forward trunnion bolt, an MLG broke away and ruptured a wing fuel tank while an airplane was being operated off the runway. The actions specified by the proposed AD are intended to ensure that the MLG separates from the wing when it is subjected to unpredictable overloads during abnormal operations, and to prevent consequent primary structural damage to the airplane. DATES: Comments must be received by March 9, 1998. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 97-NM-14-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: Ronald Atmur, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone (562) 627-5224; fax (562) 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 specified above. All communications received on or before the closing date for comments, specified above, will be [[Page 3268]] 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 97-NM-14-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-114, Attention: Rules Docket No. 97-NM-14-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion The FAA has received a report indicating that, while a McDonnell Douglas Model DC-10-10 series airplane was being operated off the runway, a main landing gear (MLG) broke away and ruptured the wing fuel tank. The results of analysis and testing conducted by the manufacturer revealed that certain fasteners (e.g., the forward trunnion bolt and the bolts for the attach fitting), which attach the MLG to the rear spar of the wing, are overstrength. Consequently, the MLG may not separate from the airplane, as designed, when unpredictable overloads are placed on the MLG during abnormal operations. This condition, if not corrected, could result in primary structural damage to the airplane. Explanation of Relevant Service Information The FAA has reviewed and approved McDonnell Douglas DC-10 Service Bulletin 57-78, Revision 1, dated August 26, 1986 (for Model DC-10-10 series airplanes), which describes procedures for replacing 24 TL taper-lok attachments that attach the left and right MLG attach fitting assemblies on each wing with heat-treat TLH taper-lok attachments. This service bulletin also describes procedures for replacing the forward trunnion bolts on the left and right MLG of each wing with ``zero margin'' trunnion bolts. The FAA also has reviewed and approved McDonnell Douglas DC-10 Service Bulletin 57-79, Revision 1, dated September 21, 1979, as revised by McDonnell Douglas DC-10 Service Bulletin 57-79, Service Bulletin Change Notification, dated January 23, 1980 (for Model DC-10- 10 series airplanes). This service bulletin describes procedures for replacing the 1\1/2\-inch-diameter bolts that attach the left and right MLG attach fitting and rear spar of each wing with 1\1/4\-inch-diameter bolts and bushings, and installing bolt retainers. In addition, the FAA has reviewed and approved McDonnell Douglas DC-10 Service Bulletin 57-82, dated February 19, 1980 (for Model DC-10- 30 and -40 series airplanes). This service bulletin describes procedures for replacing the forward trunnion bolts of the left and right MLG of each wing with ``zero margin'' trunnion bolts. For certain groups of airplanes, the service bulletin also describes procedures for replacing the 1\1/2\-inch-diameter bolts that attach the left and right MLG attach fitting and rear spar of each wing with 1\1/4\-inch-diameter bolts and bushings, and installing bolt retainers. Accomplishment of the replacement of all of these fasteners will allow the MLG to separate from the wing. This separation is intended to minimize the possibility of primary structural damage to the airplane when the MLG is subjected to unpredictable overloads during abnormal operations. Explanation of Requirements of Proposed Rule Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type of design, the proposed AD would require accomplishment of the actions specified in the service bulletins described previously in accordance with the procedures specified in those service bulletins. Cost Impact For McDonnell Douglas Model DC-10-10 Series Airplanes There are approximately 119 Model DC-10-10 series airplanes of the affected design in the worldwide fleet, and 108 airplanes of U.S. registry that would be affected by the proposed requirements for replacement of taper-lok attachments and forward trunnion bolts. The FAA estimates that it would take approximately 462 work hours per airplane to accomplish these proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $47,000 per airplane. Based on these figures, the cost impact of these proposed actions on U.S. operators is estimated to be $8,069,760, or $74,720 per airplane. There are approximately 111 Model DC-10-10 series airplanes of the affected design in the worldwide fleet, and 82 airplanes of U.S. registry that would be affected by the proposed requirements for replacement of larger attach bolts and installation of bolt retainers. The FAA estimates that it would take approximately 500 work hours per airplane to accomplish these proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $11,734 per airplane. Based on these figures, the cost impact of these proposed actions on U.S. operators is estimated to be $3,422,188, or $41,734 per airplane. For McDonnell Douglas Model DC-10-30 and DC-10-40 Series Airplanes There are approximately 168 Model DC-10-30 and DC-10-40 series airplanes of the affected design in the worldwide fleet, and 82 airplanes of U.S. registry that are identified as Groups I and II airplanes in the relevant service bulletins and that would be affected by the proposed requirements for replacement of larger attach bolts, installation of bolt retainers, and replacement of forward trunnion bolts. The FAA estimates that it would take approximately 576 work hours per airplane to accomplish these proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $20,000 per airplane. Based on these figures, the cost impact of these proposed actions on U.S. operators is estimated to be $4,473,920, or $54,560 per airplane. There are approximately 20 Model DC-10-30 and DC-10-40 series airplanes of the affected design in the worldwide fleet, and 6 airplanes of U.S. registry that are identified as Group III airplanes in the relevant service bulletins and that would be affected by the proposed requirements for replacement of forward trunnion bolts. The FAA estimates that it would take approximately 76 work hours per airplane to accomplish this proposed action, and that the average labor rate is $60 per work hour. Required parts would cost approximately $15,800 per airplane. Based on these figures, the cost impact of this proposed action on U.S. operators is estimated to be $122,160, or $20,360 per airplane. The cost impact figures discussed above are based on assumptions that no [[Page 3269]] operator has yet accomplished the proposed action, and that no operator would accomplish that action in the future if this AD were not adopted. However, the FAA has been advised that the following actions have been accomplished on Model DC-10-10 series airplanes in accordance with the requirements of this proposed AD:Taper-lok attachments and forward trunnion bolts have been replaced on 77 U.S.-registered airplanes. Therefore, the future economic cost impact of those proposed actions on U.S. operators is now only $2,316,320. Larger attach bolts have been replaced and bolt retainers have been installed on 77 U.S.-registered airplanes. Therefore, the future economic cost impact of those proposed actions on U.S. operators is now only $208,670. The FAA also has been advised that the following actions have been accomplished on Model DC-10-30 and DC-10-40 series airplanes in accordance with the requirements of this proposed AD: Forward trunnion bolts and larger attach bolts have been replaced and bolt retainers have been installed on 40 U.S.-registered airplanes identified as Groups I and II airplanes in the relevant service bulletins. Therefore, the future economic cost impact of those proposed actions on U.S. operators is now only $2,291,520. Forward trunnion bolts have been replaced on 3 U.S.- registered airplanes identified as Group III airplanes in the relevant service bulletins. Therefore, the future economic cost impact of this proposed action on U.S. operators is now only $61,080. Regulatory Impact 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 97-NM-14-AD. Applicability: Model DC-10-10, DC-10-30, and DC-10-40 series airplanes; certificated in any category; as listed in the following McDonnell Douglas service bulletins: McDonnell Douglas DC-10 Service Bulletin 57-78, Revision 1, dated August 26, 1986; McDonnell Douglas DC-10 Service Bulletin 57-79, Revision 1, dated September 21, 1979, as revised by McDonnell Douglas DC-10 Service Bulletin Change Notification 57-79, dated January 23, 1980; and McDonnell Douglas DC-10 Service Bulletin 57-82, dated February 19, 1980. 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 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 (e) 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 ensure that the main landing gear (MLG) separates from the wing when it is subjected to unpredictable overloads during abnormal operations, and to prevent consequent primary structural damage to the airplane, accomplish the following: (a) For Model DC-10-10 series airplanes, as listed in McDonnell Douglas DC-10 Service Bulletin 57-78, Revision 1, dated August 26, 1986: Within 5 years after the effective date of this AD, accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD, in accordance with the service bulletin. (1) Replace 24 TL taper-lok attachments that attach the left and right MLG attach fitting assemblies on each wing with heat-treat TLH taper-lok attachments in accordance with the service bulletin. And (2) Replace each forward trunnion bolt on the left and right MLG of each wing with a ``zero margin'' trunnion bolt in accordance with the service bulletin. Note 2: Replacement of taper-lok attachments and forward trunnion bolts accomplished prior to the effective date of this AD in accordance with McDonnell Douglas DC-10 Service Bulletin 57-78, dated February 19, 1980, is considered acceptable for compliance with the requirements of paragraphs (a)(1) and (a)(2) of this AD. (b) For Model DC-10-10 series airplanes, as listed in McDonnell Douglas DC-10 Service Bulletin 57-79, Revision 1, dated September 21, 1979, as revised by McDonnell Douglas DC-10 Service Bulletin Change Notification 57-79, dated January 23, 1980: Within 5 years after the effective date of this AD, replace each 1\1/2\-inch- diameter bolt and bushing that attach the left and right MLG attach fitting and rear spar of each wing with a 1\1/4\-inch-diameter bolt, and install bolt retainers, in accordance with the service bulletin and service bulletin change notification. Note 3: Replacement of 1\1/2\-inch-diameter bolts and installation of bolt retainers prior to the effective date of this AD in accordance with McDonnell Douglas DC-10 Service Bulletin 57- 79, dated June 5, 1979, are considered acceptable for compliance with the requirements of paragraph (b) of this AD. (c) For Model DC-10-30 and DC-10-40 series airplanes: Except as provided by paragraph (d) of this AD, within 5 years after the effective date of this AD, accomplish the requirements of paragraph (c)(1) or (c)(2) of this AD, as applicable, in accordance with McDonnell Douglas DC-10 Service Bulletin 57-82, dated February 19, 1980. (1) For airplanes identified as Groups I and II in the service bulletin: Replace each forward trunnion bolt on the left and right MLG of each wing with a ``zero margin'' forward trunnion bolt; replace each 1\1/2\-inch-diameter bolt and bushing that attach the left and right MLG attach fitting and rear spar of each wing with a 1\1/4\-inch-diameter bolt, and install bolt retainers, in accordance with the service bulletin. (2) For airplanes identified as Group III in the service bulletin: Replace each forward trunnion bolt on the left and right MLG of each wing with a ``zero margin'' trunnion bolt in accordance with the service bulletin. (d) For Model DC-10-30 and DC-10-40 airplanes: Installation of a trunnion bolt having part number (P/N) ARG7558-501 or P/N ARG7558- 507 on the MLG, in accordance with AD 96-03-05, amendment 39-9502, constitutes terminating action for the requirement to replace the trunnion bolts for that landing gear, as required in paragraph (c)(1) or (c)(2) of this AD. [[Page 3270]] (e) 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 Aircraft Certification Office (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. Note 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. (f) 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 January 14, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-1427 Filed 1-21-98; 8:45 am] BILLING CODE 4910-13-U