[Federal Register Volume 62, Number 116 (Tuesday, June 17, 1997)] [Proposed Rules] [Pages 32701-32703] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 97-15767] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 97-NM-02-AD] RIN 2120-AA64 Airworthiness Directives; British Aerospace Model BAe 146 and Model Avro 146-RJ 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 British Aerospace Model BAe 146 and Model Avro 146-RJ series airplanes. This proposal would require repetitive detailed visual inspections of the top wing skins for stress corrosion cracks, damage, or missing surface protective finish of the metallic surfaces; and repair, if necessary. This proposal is prompted by reports of stress corrosion cracks found on the top wing skin during routine inspection on three airplanes. The actions specified by the proposed AD are intended to detect and correct such cracking, which could result in reduced structural integrity of the wing. DATES: Comments must be received by July 28, 1997. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 97-NM-02-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 British Aerospace Regional Aircraft Limited, Avro International Aerospace Division, Customer Support, Woodford Aerodrome, Woodford, Cheshire SK7 1QR, England. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. FOR FURTHER INFORMATION CONTACT: Tim Backman, Aerospace Engineer, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2797; 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 97-NM-02-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. 97-NM-02-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 Model BAe 146 and Model Avro 146-RJ series airplanes. The CAA advises that airplanes with wing skins made from 7150-T651 aluminum are subject to stress corrosion cracking. During routine inspections, stress corrosion cracks on the top wing skin were found on three of the affected airplanes. Analysis has revealed that this stress corrosion cracking is only a problem on Model BAe 146 and Model Avro 146-RJ series airplanes with wing skins made from 7150-T651 aluminum. This condition, if not detected and corrected in a timely manner, could result in reduced structural integrity of the wing. Explanation of Relevant Service Information British Aerospace has issued Service Bulletin SB.57-49, dated June 4, 1996, which describes procedures for visually inspecting the top wing skin for stress corrosion cracks, damage, or missing surface protective finish of the metallic surfaces. The service bulletin also provides procedures for application of a protective finish of the metallic surfaces, if necessary. The CAA classified this service bulletin as mandatory and issued British airworthiness directive 005- 06-96, dated June 4, 1996, in order to assure the continued airworthiness of these airplanes in the United Kingdom. FAA's Conclusions These airplane models are manufactured in the United Kingdom and are 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 [[Page 32702]] 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 repetitive detailed visual inspections of the top wing skins for stress corrosion cracking, damage, or missing surface protective finish of the metallic surfaces, and repair, if necessary. The proposed inspections and a certain repair would be required to be accomplished in accordance with the service bulletin described previously. Repair of any corrosion cracking would be required to be accomplished in accordance with a method approved by the FAA. Cost Impact The FAA estimates that 12 British Aerospace Model BAe 146 and Model Avro 146-RJ series airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 4 work hours per airplane to accomplish the proposed inspections, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the initial inspection proposed by this AD on U.S. operators is estimated to be $2,880, or $240 per airplane, per inspection cycle. 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: British Aerospace Regional Aircraft Limited, Avro International Aerospace Division (Formerly British Aerospace, plc; British Aerospace Commercial Aircraft Limited): Docket 97-NM-02-AD. Applicability: Model BAe 146 and Model Avro 146-RJ series airplanes, certificated in any category, having wing skins made from 7150-T651 aluminum, and having the following serial numbers: ---------------------------------------------------------------------------------------------------------------- Model Serial numbers ---------------------------------------------------------------------------------------------------------------- BAe 146-100 and 100A............. All beginning with E1144. BAe 146-200 and 200A............. All beginning with E2148 (including E2227). BAe 146-300 and 300A............. All beginning with E3141 (including E3222). Avro 146-RJ70 and 70A............ All beginning with E1223. Avro 146-RJ85 and 85A............ E2208, and all beginning with E2226, excluding E2227. Avro 146-RJ100 and 100A.......... All beginning with E3221, excluding E3222. ---------------------------------------------------------------------------------------------------------------- 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 (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 detect and correct stress corrosion cracking in the wing skin, which could result in reduced structural integrity of the wing, accomplish the following: (a) Within 4 months after the effective date of this AD; and thereafter at intervals not to exceed 4,000 landings or 2 years, whichever occurs first: Perform a detailed visual inspection of the top wing skins to detect stress corrosion cracking, and any damaged or missing surface protective finish that exposes the metallic surfaces, in accordance with British Aerospace Service Bulletin SB.57-49, dated June 4, 1996. (1) If any damaged or missing surface protective finish is detected, and no cracking or corrosion is detected, prior to further flight, reapply the protective finish in accordance with the service bulletin. Repeat the detailed visual inspection, thereafter, at intervals not to exceed 4,000 landings or 2 years, whichever occurs first. (2) If any cracking is detected, prior to further flight, repair in accordance with a method approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Note 2: During the detailed visual inspections of the top wing skins, pay particular attention to the edge of cutouts, skin edges, and attachment bolt holes. (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, Standardization Branch, ANM-113. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then [[Page 32703]] send it to the Manager, Standardization Branch, ANM-113. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113. (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. Issued in Renton, Washington, on June 10, 1997. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 97-15767 Filed 6-16-97; 8:45 am] BILLING CODE 4910-13-U