[Federal Register Volume 62, Number 228 (Wednesday, November 26, 1997)] [Proposed Rules] [Pages 63042-63044] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 97-31023] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 96-NM-200-AD] RIN 2120-AA64 Airworthiness Directives; British Aerospace BAe Model ATP 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 British Aerospace BAe Model ATP airplanes. This proposal would require repetitive inspections to detect uneven wear of the heat pack of the main landing gear (MLG) brake unit; measurement and setting of the wear remaining length (WRL) of the wear indicator pin (WIP); and replacement of the brake heat pack unit with a serviceable unit, if necessary. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to detect uneven wear of the brake heat pack unit and prevent failure of the pressure stator of the MLG brake unit, which could result in reduced braking efficiency and consequent longer stopping distances upon landing. DATES: Comments must be received by December 26, 1997. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 96-NM-200-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 AI(R) American Support, Inc., 13850 McLearen Road, Herndon, Virginia 20171. This information may be examined at the FAA, Transport [[Page 63043]] Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. FOR FURTHER INFORMATION CONTACT: International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149. 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 96-NM-200-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-200-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, notified the FAA that an unsafe condition may exist on certain British Aerospace BAe Model ATP airplanes. The CAA advises it received reports indicating that the heat pack unit of the main landing gear (MLG) brake unit has exhibited uneven wear at the pressure stator/first rotor interface in some instances, which has resulted in a small number of failures of the pressure stator. The pressure stator failures have been attributed to incorrect wear remaining length (WRL) indicated by the wear indicator pin (WIP). Such uneven wear and/or failure of the pressure stator/first rotor interface of the brake units, if not corrected, could result in reduced braking efficiency and consequent longer stopping distances upon landing. Explanation of Relevant Service Information Jetstream has issued Service Bulletin ATP/J61-32-71, dated May 23, 1996, and Revision 1, dated June 18, 1996, which describe procedures for repetitive inspections to detect uneven wear of the heat pack of the MLG brake unit at the pressure stator/first rotor interface; measurement and setting of the WRL of the WIP to indicate the correct amount of allowable remaining wear of the brake heat pack unit; and replacement of the brake heat pack unit with a serviceable unit, if necessary. (The Jetstream service bulletin references Dunlop service Bulletin AHA1612/AHA2004-32-1122, dated April 16, 1996, as an additional source of service information for inspecting the brakes, measuring the WRL of the WIP, and setting the corrected length of the pin. The CAA classified the Jetstream service bulletin as mandatory and issued British airworthiness directive 002-05-96 in order to assure the continued airworthiness of these airplanes in the United Kingdom. FAA's Conclusions This airplane model is manufactured in the United Kingdom and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States. Explanation of Requirements of Proposed Rule Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously. Differences Between Proposed AD and Service Information Operators should note that certain procedures described in the referenced Dunlop Service Bulletin are not included in this AD. Those procedures address the possible delay in the accomplishment of some of the work tasks due to the lack of qualified persons to set the WRL of the WIP. However, this AD permits no delay in setting the corrected length of the pin. Cost Impact The FAA estimates that 10 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 5 work hours 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 $3,000, or $300 per airplane. The cost impact figures discussed above are 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. [[Page 63044]] 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: British Aerospace Regional Aircraft [Formerly Jetstream Aircraft Limited; British Aerospace (Commercial Aircraft) Limited]: Docket 96-NM-200-AD. Applicability: BAe Model ATP airplanes having constructors numbers 2002 through 2067 inclusive, certificated in any category. Note 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 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 detect uneven wear of the brake heat pack unit and prevent failure of the pressure stator of the main landing gear (MLG) brake unit, which could result in reduced braking efficiency and consequent longer stopping distances upon landing, accomplish the following: (a) Within 300 hours time-in-service (TIS) after the effective date of this AD: Perform an inspection of the brake units of the left and right MLG to detect uneven wear at the pressure stator/ first rotor interface, measure the wear remaining length (WRL) of the wear indicator pin (WIP), and accomplish the action specified in paragraph (a)(1) or (a)(2) of this AD, as applicable; in accordance with Jetstream Service Bulletin ATP/J61-32-71, dated May 23, 1996, or Revision 1, dated June 18, 1996. Note 2: Jetstream Service Bulletin ATP/J61-32-71, dated May 23, 1996, and Revision 1, dated June 18, 1996, reference Dunlop Service Bulletin AHA1612/AHA2004-32-1122, dated April 16, 1996, as an additional source of service information for procedures to inspect the brakes, measure the wear remaining length (WRL) of the wear indicator pin (WIP), and set the corrected length of the pin. (1) If the WRL of the WIP is greater than or equal to 0.5 inches: Repeat the action required in paragraph (a) of this AD thereafter at intervals not to exceed 300 hours TIS. (2) If the WRL of the WIP is less than 0.5 inches: Prior to further flight, measure the thickness of the pressure stator and accomplish the action specified in paragraph (a)(2)(i) or (a)(2)(ii) of this AD, as applicable; and repeat the action required in paragraph (a) of this AD thereafter at intervals not to exceed 300 hours TIS. (i) If the pressure stator is less than or equal to 0.31 inches thick: Replace the heat pack of the MLG brake unit with a serviceable unit and set the WRL of the WIP to indicate the corrected WRL measurement. (ii) If the pressure stator exceeds 0.31 inches thick: Set the WRL of the WIP to indicate the corrected WRL measurement. (b) If, during any inspection required by this AD, the WRL of the WIP on any brake unit shows that the wear status of the brake heat pack is outside the acceptable limits specified in Jetstream Service Bulletin ATP/J61-32-71, dated May 23, 1996, or Revision 1, dated June 18, 1996: Prior to further flight, replace the brake heat pack unit with a serviceable unit in accordance with the referenced service bulletin; and repeat the action required in paragraph (a) of this AD thereafter at intervals not to exceed 300 hours TIS. (c) An alternative method of compliance or adjustment of the initial compliance time that provides an acceptable level of safety may be used if approved by the Manager, International Branch, ANM- 116, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add additional comments, and then send it to the Manager, International Branch, ANM-116. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116. (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. Note 4: The subject of this AD is addressed in British airworthiness directive 002-05-96. Issued in Renton, Washington, on November 19, 1997. Stewart R. Miller, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 97-31023 Filed 11-25-97; 8:45 am] BILLING CODE 4910-13-U