[Federal Register Volume 63, Number 63 (Thursday, April 2, 1998)] [Proposed Rules] [Pages 16170-16172] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-8575] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 97-NM-279-AD] RIN 2120-AA64 Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-145 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 EMBRAER Model EMB-145 series airplanes. This proposal would require inspection of the main landing gear (MLG) bushing seats to detect cracks, and repair of the bushing hole or replacement of strut bushings with new bushings, if necessary. This proposal also would require replacement of the plain bearings of the MLG shock absorber with new bearings. 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 prevent structural failure of the MLG due to fatigue cracking of the strut bushing seat. DATES: Comments must be received by May 4, 1998. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 97-NM-279-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 Empresa Brasileira de Aeronautica S.A. (EMBRAER), P.O. Box 343--CEP 12.225, Sao Jose dos Campos--SP, Brazil. This information may be examined at the FAA, Transport Airplane Directorate, [[Page 16171]] 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Small Airplane Directorate, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia. FOR FURTHER INFORMATION CONTACT: Curtis A. Jackson, Aerospace Engineer, Airframe and Propulsion Branch, ACE-117A, FAA, Small Airplane Directorate, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30337-2748; telephone (770) 703-6083; fax (770) 703-6097. 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-279-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-279-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion The Departmento de Aviacao Civil (DAC), which is the airworthiness authority for Brazil, notified the FAA that an unsafe condition may exist on certain EMBRAER Model EMB-145 series airplanes. The DAC advises that, during fatigue testing of the main landing gear (MLG) strut, jamming of the plain bearing of the upper hinge point of the shock absorber occurred. This caused the bushings to turn and scratch the surface of the bushing seat of the MLG struts, and the initiation of a fatigue crack. Such fatigue cracking, if not detected and corrected in a timely manner, could result in structural failure of the MLG. Explanation of Relevant Service Information EMBRAER has issued Service Bulletin 145-32-0012, dated September 1, 1997, which describes procedures for a one-time liquid penetrant inspection to detect cracking of the flanged bushing seats of the main landing gear (MLG); a one-time inspection of the bushing holes using a bore micrometer to determine the dimension of the holes; and replacement of the strut bushings with new bushings, if necessary. In addition, EMBRAER has issued Service Bulletin 145-32-0009, dated September 1, 1997, which describes procedures for replacement of the plain bearings of the MLG shock absorber with new bearings. Accomplishment of the action specified in this service bulletin is intended to adequately address the identified unsafe condition. The DAC classified these service bulletins as mandatory and issued Brazilian airworthiness directive 97-10-02, dated October 13, 1997, in order to assure the continued airworthiness of these airplanes in Brazil. FAA's Conclusions This airplane model is manufactured in Brazil 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 DAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DAC, 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 bulletins described previously, except as discussed below. Differences Between Proposed Rule and Service Bulletins Operators should note that, although EMBRAER Service Bulletin 145- 32-0012, dated September 1, 1997, specifies that the manufacturer may be contacted for disposition of an oversized flanged bushing seat, this proposal would require repair of this condition to be accomplished in accordance with a method approved by the FAA. Cost Impact The FAA estimates that 9 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 inspections, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspections proposed by this AD on U.S. operators is estimated to be $540, or $60 per airplane. The FAA estimates that it would take approximately 6 work hours per airplane to accomplish the proposed replacement of the plain bearings, at an average labor rate of $60 per work hour. Required parts would be provided by the manufacturer at no cost to operators. Based on these figures, the cost impact of the replacement proposed by this AD on U.S. operators is estimated to be $3,240, or $360 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 [[Page 16172]] 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: Empresa Brasileira de Aeronautica S.A. (EMBRAER): Docket 97-NM-279- AD. Applicability: Model EMB-145 series airplanes, serial numbers 145004 through 145018 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 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 prevent structural failure of the main landing gear (MLG) due to fatigue cracking of the strut bushing seat, accomplish the following: (a) Prior to the accumulation of 2,000 total flight cycles, or within 100 flight cycles after the effective date of this AD, whichever occurs later, accomplish paragraphs (a)(1), (a)(2), and (a)(3) of this AD. (1) Perform a one-time liquid penetrant inspection to detect cracking of the flanged bushing seats of the MLG, in accordance with EMBRAER Service Bulletin 145-32-0012, dated September 1, 1997. If any crack is found, prior to further flight, repair in accordance with a method approved by the Manager, Atlanta Aircraft Certification Office (ACO), FAA, Small Airplane Directorate. (2) Perform a one-time inspection of the bushing holes using a bore micrometer to determine the dimension of the holes, in accordance with EMBRAER Service Bulletin 145-32-0012, dated September 1, 1997. Prior to further flight, accomplish paragraph (a)(2)(i) or (a)(2)(ii) of this AD, as applicable. (i) If the dimension of the bushing hole is less than 49.2 mm, perform the applicable corrective actions specified in the service bulletin. (ii) If the dimension of the bushing hole is greater than or equal to 49.2 mm, repair in accordance with a method approved by the Manager, Atlanta ACO. (3) Replace the plain bearing of the MLG shock absorber with a new bearing in accordance with EMBRAER Service Bulletin 145-32-0009, dated September 1, 1997. (b) As of the effective date of this AD, no person shall install a plain bearing having part number ABC24VG (NMB) on the shock absorber of the MLG of any airplane. (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, Atlanta Aircraft Certification Office (ACO), FAA, Small 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, Atlanta ACO. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta 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. Note 3: The subject of this AD is addressed in Brazilian airworthiness directive 97-10-02, dated October 13, 1997. Issued in Renton, Washington, on March 25, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-8575 Filed 4-1-98; 8:45 am] BILLING CODE 4910-13-U