[Federal Register Volume 62, Number 174 (Tuesday, September 9, 1997)]
[Rules and Regulations]
[Pages 47360-47362]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-23860]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-221-AD; Amendment 39-10124; AD 97-19-04]
RIN 2120-AA64


Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. 
(EMBRAER) Model EMB-145 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain EMBRAER Model EMB-145 series airplanes. This 
action requires repetitive visual inspections to detect cracks in the 
firewall of the auxiliary power unit (APU), and repair, if necessary. 
This AD also requires installation of a visco-elastic damper blanket on 
the firewall, which constitutes terminating action for the repetitive 
inspection requirements. This amendment is prompted by reports 
indicating that cracks were found in the firewall of the APU due to 
vibration of the firewall. The actions specified in this AD are 
intended to prevent such cracking, which could result in reduced 
structural integrity of the fuselage and empennage in the event that a 
fire penetrates through the firewall of the APU.

DATES: Effective September 24, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 24, 1997.
    Comments for inclusion in the Rules Docket must be received on or 
before October 9, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-221-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The service information referenced in this AD 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, 1895 Phoenix Boulevard, Suite 
450, Atlanta, Georgia; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Curtis Jackson, Aerospace Engineer, 
Airframe and Propulsion Branch, ACE-117A, the FAA, Small Airplane 
Directorate, Atlanta Aircraft Certification Office, 1895 Phoenix 
Boulevard, Suite 450, Atlanta, Georgia 30349; telephone (770) 703-6083; 
fax (770) 703-6097.

SUPPLEMENTARY INFORMATION: The Departamento de Aviacao Civil (DAC), 
which is the airworthiness authority for Brazil, recently notified the 
FAA that an unsafe condition may exist on certain EMBRAER Model EMB-145 
series airplanes. The CTA advises that it has received reports 
indicating that, during a routine inspection, cracks were found in the 
firewall of the auxiliary power unit (APU). In one incident, the crack 
was 24 inches in length. The cause of such cracking has been attributed 
to vibration of the firewall in the location where the recessed area of 
the shell is spot welded to the firewall. Cracking in the firewall of 
the APU, if not corrected, could result in reduced structural integrity 
of the fuselage and empennage in the event that a fire penetrates 
through the firewall of the APU.

Explanation of Relevant Service Information

    EMBRAER has issued Service Bulletin 145-53-0004, dated July 28, 
1997, which describes procedures for repetitive visual inspections to 
detect cracks in the firewall of the APU. The service bulletin also 
describes procedures for installation of a visco-elastic damper blanket 
on the firewall, which eliminates the need for the repetitive 
inspections. The DAC issued Brazilian airworthiness directive NPR/AD-
97-145-02, dated July 30, 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

[[Page 47361]]

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 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, this AD is being issued to prevent cracking in 
the firewall of the APU, which could result in reduced structural 
integrity of the fuselage and empenage in the event that a fire 
penetrates through the firewall of the APU. This AD requires repetitive 
visual inspections to detect cracks in the firewall of the APU, and 
repair, if necessary. This AD also requires installation of a visco-
elastic damper blanket on the firewall, which constitutes terminating 
action for the repetitive inspection requirements. The inspections and 
installation are required to be accomplished in accordance with the 
service bulletin described previously.

Differences Between the AD and the Relevant Service Information

    Operators should note that, although the referenced service 
bulletin specifies that the manufacturer must be contacted for 
disposition of certain conditions, this AD requires the repair of those 
conditions to be accomplished in accordance with a method approved by 
the FAA.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 97-NM-221-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

97-19-04  EMPRESA BRASILEIRA DE AERONAUTICA S.A.: Amendment 39-
10124. Docket 97-NM-221-AD.

    Applicability: Model EMB-145 series airplanes, serial numbers 
145004 through 145019 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 prevent cracking in the firewall of the auxiliary power unit 
(APU), which could result in reduced structural integrity of the 
fuselage and empennage in the event that a fire penetrates through 
the firewall of the APU, accomplish the following:
    (a) Within 50 flight hours after the effective date of this AD, 
perform a visual inspection to detect cracks in the firewall of the 
APU, in accordance with EMBRAER Service Bulletin 145-53-0004, dated 
July 28, 1997.
    (1) If no crack is detected, repeat the visual inspection 
thereafter at intervals not to exceed 100 flight hours.
    (2) If any crack is detected, prior to operation of the APU, 
repair it in accordance with a method approved by the Manager, 
Atlanta Aircraft Certification Office (ACO), FAA, Small Airplane 
Directorate.

[[Page 47362]]

    (b) Within 200 flight hours after the effective date of this AD, 
install the visco-elastic damper blanket on the firewall in 
accordance with EMBRAER Service Bulletin 145-53-0004, dated July 28, 
1997. Accomplishment of the installation constitutes terminating 
action for the repetitive inspection requirements of this AD.
    (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.
    (e) The inspection and installation shall be done in accordance 
with EMBRAER Service Bulletin 145-53-0004, dated July 28, 1997. This 
incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Empresa Brasileira de Aeronautica 
S.A. (EMBRAER), P.O. Box 343--CEP 12.225, Sao Jose dos Campos--SP, 
Brazil. Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
FAA, Small Airplane Directorate, Atlanta Aircraft Certification 
Office, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.
    (f) This amendment becomes effective on September 24, 1997.

    Note 3: The subject of this AD is addressed in Brazilian 
airworthiness directive NPR/AD-97-145-02, dated July 30, 1997.

    Issued in Renton, Washington, on September 3, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-23860 Filed 9-8-97; 8:45 am]
BILLING CODE 4910-13-P