[Federal Register Volume 63, Number 149 (Tuesday, August 4, 1998)] [Proposed Rules] [Pages 41481-41483] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-20677] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 97-NM-241-AD] RIN 2120-AA64 Airworthiness Directives; Boeing Model 767-200, -300, and -300F 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 Boeing Model 767-200, - 300, and -300F series airplanes. This proposal would require replacement of the hydraulic reducer fitting in the return port of the alternate brake selector valve with a new restrictor fitting. This proposal is prompted by a report indicating that a brake housing had fractured due to high loads associated with brake vibration during landing gear retraction, which allowed the torque rod to swing free. The actions specified by the proposed AD are intended to prevent failure of the brake housing in the torque rod region, which could reduce the braking capability of the airplane and/or prevent the extension of a main landing gear by any method. DATES: Comments must be received by September 18, 1998. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 97-NM-241-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 Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. FOR FURTHER INFORMATION CONTACT: David Herron, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2672; fax (425) 227-1181. 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 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-241-AD.'' The postcard will be date stamped and returned to the commenter. [[Page 41482]] 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-241-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion The FAA has received several reports of brake vibration during landing gear retraction on Boeing Model 767 series airplanes, including one report indicating that a brake housing had fractured during landing gear retraction, allowing the torque rod to swing free. The unrestrained torque rod caused minor damage to components located in the wheel well. Failure of the brake housing would result in loss of one of the eight brakes installed on a main landing gear. Furthermore, the unrestrained torque rod could jam in the wheel well, which could damage components located in the wheel well and/or prevent the extension of a main landing gear. Failure of the brake housing has been attributed to high loads associated with brake vibration during landing gear retraction. The brake vibration is caused by excessive flow of hydraulic fluid into the alternate system metering valves during gear retract braking. Excessive brake vibration could result in failure of the brake housing in the torque rod region. This condition, if not corrected, could reduce the braking capability of the airplane and/or prevent the extension of a main landing gear by any method. Explanation of Relevant Service Information The FAA has reviewed and approved Boeing Service Bulletin 767-32- 0152, dated June 6, 1996; Revision 1, dated June 27, 1996; and Revision 2, dated July 10, 1997. These service bulletins describe procedures for replacement of the hydraulic reducer fitting in the return port of the alternate brake selector valve with a new restrictor fitting. Accomplishment of the replacement specified in the service bulletins is intended to adequately address the identified unsafe condition. 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 design, the proposed AD would require accomplishment of the actions specified in the service bulletins described previously. Cost Impact There are approximately 373 airplanes of the affected design in the worldwide fleet. The FAA estimates that 86 airplanes of U.S. registry would be affected by this proposed AD, and that it would take approximately 4 work hours per airplane to accomplish the proposed replacement at an average labor rate of $60 per work hour. Required parts would cost approximately $104 per airplane. Based on these figures, the cost impact of the replacement proposed by this AD on U.S. operators is estimated to be $29,584, or $344 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. 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: Boeing: Docket 97-NM-241-AD. Applicability: Model 767-200, -300, and -300F series airplanes, line positions 1 through 607 inclusive; equipped with carbon brakes; 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 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 (b) 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 failure of the brake housing in the torque rod region, which could reduce the braking capability of the airplane and/or prevent the extension of a main landing gear, accomplish the following: (a) Within 360 days after the effective date of this AD, replace the hydraulic reducer fitting in the return port of the alternate brake selector valve with a new restrictor fitting, in accordance with Boeing Service Bulletin 767-32-0152, dated June 6, 1996; Revision 1, dated June 27, 1996; or Revision 2, dated July 10, 1997. (b) 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, Seattle 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, Seattle ACO. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. (c) 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. [[Page 41483]] Issued in Renton, Washington, on July 27, 1998. S.R. Miller, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-20677 Filed 8-3-98; 8:45 am] BILLING CODE 4910-13-U