[Federal Register Volume 63, Number 220 (Monday, November 16, 1998)]
[Proposed Rules]
[Pages 63620-63621]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-30537]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 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.
 
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 

  Federal Register / Vol. 63, No. 220 / Monday, November 16, 1998 / 
Proposed Rules  

[[Page 63620]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-265-AD]
RIN 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).

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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 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 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. 98-30537 Filed 11-13-98; 8:45 am]
BILLING CODE 4910-13-U