Airworthiness directives: Empresa Brasileria de Aeronautica S.A.,

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Federal Register: November 16, 1998 (Volume 63, Number 220)Proposed RulesPage 63620-63621From the Federal Register Online via GPO Access [wais.access.gpo.gov]

DOCID:fr16no98-19

Proposed Rules Federal Register

This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules.

[Page 63620]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

Docket No. 98-NM-265-ADRIN 2120-AA64

Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-120 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-120 series airplanes. This proposal would require removing the thermal insulating blankets from the upper rear nacelle structure; re- positioning the engine exhaust duct; and replacing the engine exhaust bracket with a new engine exhaust bracket, if necessary. For certain airplanes, this proposal also would require installing new stainless steel plates onto the upper rear nacelle structure. 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 fretting of the titanium thermal insulating blankets, which could result in an increased risk of fire in the engine exhaust duct of the tail pipe.

DATES: Comments must be received by December 16, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-265-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, 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: Linda M. Haynes, 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) 703-6091; 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 filedin 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 98-NM-265-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. 98-NM-265-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-120 series airplanes. The DAC advises that it has received reports of fire in the engine exhaust duct of the tail pipe. Investigation revealed that the aft section of the engine exhaust duct is subject to vibration that causes relative motion between the layers of insulation blankets and the engine exhaust duct. As a result, the titanium thermal insulating blankets are subject to fretting. Such fretting produces titanium dust, which under intense heat, could spontaneously ignite. This condition, if not corrected, could result in an increased risk of fire in the engine exhaust duct of the tail pipe.

Explanation of Relevant Service Information

EMBRAER has issued Service Bulletin 120-54-0035, Change 02, dated May 29, 1998, which describes procedures for removing the thermal insulating blankets from the upper rear nacelle structure; re- positioning the engine exhaust duct with the use of shims; and replacing the engine exhaust bracket with a new engine exhaust bracket, if necessary. For certain airplanes, the service bulletin also describes procedures for installing new stainless steel plates onto the upper rear nacelle structure. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. The DAC classified this service bulletin as mandatory and issued Brazilian airworthiness directives 97-11-03, dated December 3, 1997, and 97-11-03R1, dated July 6, 1998, 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

[Page 63621]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 bulletin described previously.

Cost Impact

The FAA estimates that 171 airplanes of U.S. registry would be affected by this proposed AD.

It would take approximately 9 work hours per airplane to accomplish the actions on airplanes listed in ``Part I'' of EMBRAER Service Bulletin 120-54-0035, Change 02, at an average labor rate of $60 per work hour. Required parts would cost approximately $337 per airplane. Based on these figures, the cost impact of the proposed requirements of this AD on U.S. operators of airplanes listed in ``Part I'' of the service bulletin is estimated to be $877 per airplane.

It would take approximately 2 work hours per airplane to accomplish the actions on airplanes listed in ``Part II'' of EMBRAER Service Bulletin 120-54-0035, Change 02, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the proposed requirements of this AD on U.S. operators of airplanes listed in ``Part II'' of the service bulletin is estimated to be $120 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.

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 98-NM-265- AD.

Applicability: Model EMB-120 series airplanes, serial numbers (S/N) 120003, 120004, and 120006 through 120336 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 (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 prevent fretting of the titanium thermal insulating blankets, which could result in an increased risk of fire in the engine exhaust duct of the tail pipe, accomplish the following:

  (a) For airplanes identified in ``Part I'' of the effectivity listing of EMBRAER Service Bulletin 120-54-0035, Change 02, dated May 29, 1998: Within 2,400 flight hours after the effective date of this AD, accomplish paragraphs (a)(1) and (a)(2) in accordance with the service bulletin.

  (1) Remove the thermal insulating blankets from the upper rear nacelle structure.

  (2) Install new stainless steel plates onto the upper rear nacelle structure.

  (b) For airplanes identified in ``Part II'' of the effectivity listing of EMBRAER Service Bulletin 120-54-0035, Change 02, dated May 29, 1998: Within 2,400 flight hours after the effective date of this AD, remove the thermal insulating blankets from the upper rear nacelle structure in accordance with the service bulletin.

  (c) For all airplanes: Prior to further flight following accomplishment of either paragraph (a) or (b) of this AD, as applicable, re-position the engine exhaust duct with the use of shims in accordance with EMBRAER Service Bulletin 120-54-0035, Change 02, dated May 29, 1998. If it is not possible to re-position the engine exhaust duct with the use of shims as specified in the service bulletin, prior to further flight, replace the rear exhaust duct bracket with a new rear exhaust duct bracket, in accordance with the ``NOTE'' in paragraph 1.3.1.1 of the Planning section of the service bulletin.

  (d) As of the effective date of this AD, no person shall install on any airplane a thermal insulating blanket having part number (P/ N) 120-35411-025, -035, -036, 120035413-001, or 12035411-002.

  (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, 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.

  (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.

Note 3: The subject of this AD is addressed in Brazilian airworthiness directives 97-11-03, dated December 3, 1997, and 97- 11-03R1, dated July 6, 1998.

Issued in Renton, Washington, on November 9, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

FR Doc. 98-30537Filed11-13-98; 8:45 amBILLING CODE 4910-13-U

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