[Federal Register Volume 72, Number 204 (Tuesday, October 23, 2007)]
[Proposed Rules]
[Pages 59967-59969]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-20821]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0075; Directorate Identifier 2007-NM-171-AD]
RIN 2120-AA64


Airworthiness Directives; EMBRAER Model EMB-120, -120ER, -120FC, 
-120QC, and -120RT Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above. This proposed AD results from mandatory 
continuing airworthiness information (MCAI) originated by an aviation 
authority of another country to identify and correct an unsafe 
condition on an aviation product. The MCAI describes the unsafe 
condition as:

    It has been found that former revisions of the Maintenance 
Review Board Report (MRBR) of the EMB-120( ) aircraft do not fully 
comply with some Critical Design Configuration Control Limitations 
(CDCCL) and Fuel System Limitations (FSL). These limitations are 
necessary to preclude ignition sources in the fuel system, as 
required by RBHA-E88/SFAR-88 (Special Federal Aviation Regulation 
No. 88).
* * * * * * *
    The potential of ignition sources, in combination with flammable 
fuel vapors, could result in fuel tank explosions and consequent loss 
of the airplane. The proposed AD would require actions that are 
intended to address the unsafe condition described in the MCAI.

DATES: We must receive comments on this proposed AD by November 23, 
2007.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-40, 1200 New 
Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Operations office (telephone (800) 647-5527) is 
in the ADDRESSES section. Comments will be available in the AD docket 
shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Dan Rodina, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
227-2125; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2007-0075; 
Directorate Identifier 2007-NM-171-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD based on those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov; including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    The Ag[ecirc]ncia Nacional de Avia[ccedil][atilde]o Civil (ANAC), 
which is the airworthiness authority for Brazil, has issued Brazilian 
Airworthiness Directive 2007-05-02, effective June 6, 2007 (referred to 
after this as ``the MCAI''), to

[[Page 59968]]

correct an unsafe condition for the specified products. The MCAI 
states:

    It has been found that former revisions of the Maintenance 
Review Board Report (MRBR) of the EMB-120( ) aircraft do not fully 
comply with some Critical Design Configuration Control Limitations 
(CDCCL) and Fuel System Limitations (FSL). These limitations are 
necessary to preclude ignition sources in the fuel system, as 
required by RBHA-E88/SFAR-88 (Special Federal Aviation Regulation 
No. 88).
    Since this condition affects flight safety, a corrective action 
is required. Thus, sufficient reason exists to request compliance 
with this AD in the indicated time limit.

    The potential of ignition sources, in combination with flammable 
fuel vapors, could result in fuel tank explosions and consequent loss 
of the airplane. The corrective action is revising the Airworthiness 
Limitations Section of the Instructions for Continued Airworthiness to 
incorporate new limitations for fuel tank systems. You may obtain 
further information by examining the MCAI in the AD docket.
    The FAA has examined the underlying safety issues involved in fuel 
tank explosions on several large transport airplanes, including the 
adequacy of existing regulations, the service history of airplanes 
subject to those regulations, and existing maintenance practices for 
fuel tank systems. As a result of those findings, we issued a 
regulation titled ``Transport Airplane Fuel Tank System Design Review, 
Flammability Reduction and Maintenance and Inspection Requirements'' 
(66 FR 23086, May 7, 2001). In addition to new airworthiness standards 
for transport airplanes and new maintenance requirements, this rule 
included Special Federal Aviation Regulation No. 88 (``SFAR 88,'' 
Amendment 21-78, and subsequent Amendments 21-82 and 21-83).
    Among other actions, SFAR 88 requires certain type design (i.e., 
type certificate (TC) and supplemental type certificate (STC)) holders 
to substantiate that their fuel tank systems can prevent ignition 
sources in the fuel tanks. This requirement applies to type design 
holders for large turbine-powered transport airplanes and for 
subsequent modifications to those airplanes. It requires them to 
perform design reviews and to develop design changes and maintenance 
procedures if their designs do not meet the new fuel tank safety 
standards. As explained in the preamble to the rule, we intended to 
adopt airworthiness directives to mandate any changes found necessary 
to address unsafe conditions identified as a result of these reviews.
    In evaluating these design reviews, we have established four 
criteria intended to define the unsafe conditions associated with fuel 
tank systems that require corrective actions. The percentage of 
operating time during which fuel tanks are exposed to flammable 
conditions is one of these criteria. The other three criteria address 
the failure types under evaluation: Single failures, single failures in 
combination with a latent condition(s), and in-service failure 
experience. For all four criteria, the evaluations included 
consideration of previous actions taken that may mitigate the need for 
further action.
    We have determined that the actions identified in this AD are 
necessary to reduce the potential of ignition sources inside fuel 
tanks, which, in combination with flammable fuel vapors, could result 
in fuel tank explosions and consequent loss of the airplane.

Relevant Service Information

    EMBRAER has issued Temporary Revision No. 22-1 of the EMB-120 
Maintenance Review Board Report (MRBR), dated November 18, 2005; and 
Section 6, Part D, Critical Design Configuration Control Limitation 
(CDCCL) of the MRBR, dated March 22, 2005. The actions described in 
this service information are intended to correct the unsafe condition 
identified in the MCAI.

FAA's Determination and Requirements of This Proposed AD

    This product has been approved by the aviation authority of another 
country, and is approved for operation in the United States. Pursuant 
to our bilateral agreement with the State of Design Authority, we have 
been notified of the unsafe condition described in the MCAI and service 
information referenced above. We are proposing this AD because we 
evaluated all pertinent information and determined an unsafe condition 
exists and is likely to exist or develop on other products of the same 
type design.

Differences Between This AD and the MCAI or Service Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have proposed different actions in this AD from those 
in the MCAI in order to follow FAA policies. Any such differences are 
highlighted in a NOTE within the proposed AD.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 109 products of U.S. registry. We also estimate that 
it would take about 1 work-hour per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $80 per 
work-hour. Based on these figures, we estimate the cost of the proposed 
AD on U.S. operators to be $8,720, or $80 per product.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect 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.
    For the reasons discussed above, I certify 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. 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.

[[Page 59969]]

    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new AD:

Empresa Brasileira de Aeronautica S.A. (EMBRAER): Docket No. FAA-
2007-0075; Directorate Identifier 2007-NM-171-AD.

Comments Due Date

    (a) We must receive comments by November 23, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Embraer Model EMB-120, -120ER, -
120FC, -120QC, and -120RT airplanes; certificated in any category.

    Note 1: This AD requires revisions to certain operator 
maintenance documents to include new inspections. Compliance with 
these inspections is required by 14 CFR 91.403(c). For airplanes 
that have been previously modified, altered, or repaired in the 
areas addressed by these inspections, the operator may not be able 
to accomplish the inspections described in the revisions. In this 
situation, to comply with 14 CFR 91.403(c), the operator must 
request approval for an alternative method of compliance according 
to paragraph (g) of this AD. The request should include a 
description of changes to the required inspections that will ensure 
the continued operational safety of the airplane. The FAA has 
provided guidance for this determination in Advisory Circular (AC) 
25-1529-1.

Subject

    (d) Air Transport Association (ATA) of America Code 28: Fuel.

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:

    It has been found that former revisions of the Maintenance 
Review Board Report (MRBR) of the EMB-120( ) aircraft do not fully 
comply with some Critical Design Configuration Control Limitations 
(CDCCL) and Fuel System Limitations (FSL). These limitations are 
necessary to preclude ignition sources in the fuel system, as 
required by RBHA-E88/SFAR-88 (Special Federal Aviation Regulation 
No. 88).
    Since this condition affects flight safety, a corrective action 
is required. Thus, sufficient reason exists to request compliance 
with this AD in the indicated time limit.
    The potential of ignition sources, in combination with flammable 
fuel vapors, could result in fuel tank explosions and consequent 
loss of the airplane. The corrective action is revising the 
Airworthiness Limitations Section of the Instructions for Continued 
Airworthiness to incorporate new limitations for fuel tank systems.

Actions and Compliance

    (f) Unless already done, do the following actions.
    (1) Within 1 month after the effective date of this AD, revise 
the Airworthiness Limitations Section (ALS) of the Instructions for 
Continued Airworthiness to incorporate Tasks 15 to 18 of Section 6--
``Part E--Fuel Systems Limitations,'' Temporary Revision No. 22-1 of 
the EMB-120 Maintenance Review Board Report (MRBR), dated November 
18, 2005. For all tasks identified in the MRBR, the initial 
compliance times start from the later of the times specified in 
paragraphs (f)(1)(i) and (f)(1)(ii) of this AD, and the repetitive 
inspections must be accomplished thereafter at the interval 
specified in the MRBR, except as provided by paragraph (f)(3) of 
this AD.
    (i) The effective date of this AD.
    (ii) The date of issuance of the original Brazilian standard 
airworthiness certificate or the date of issuance of the original 
Brazilian export certificate of airworthiness.
    (2) Within 1 month after the effective date of this AD, revise 
the ALS of the Instructions for Continued Airworthiness to 
incorporate the CDCCLs to include items 1) and 2) of Section 6--
``Part D--Critical Design Configuration Control Limitations,'' of 
the EMB-120 MRBR, dated March 22, 2005.
    (3) For the functional checks and detailed visual inspections, 
Tasks 15 to 18 of Section 6--``Part E--Fuel Systems Limitations,'' 
Temporary Revision No. 22-1 of the EMB-120 Maintenance Review Board 
Report (MRBR), dated November 18, 2005: The initial compliance time 
is within 4,000 flight hours or 48 months after the effective date 
of this AD, whichever occurs first. Thereafter those tasks must be 
accomplished at the repetitive interval specified in ``Part E--Fuel 
Systems Limitations,'' Temporary Revision No. 22-1 of the EMB-120 
Maintenance Review Board Report (MRBR), dated November 18, 2005.
    (4) Except as provided by paragraph (g) of this AD: After 
accomplishing the actions specified in paragraphs (f)(1) and (f)(2) 
of this AD, no alternative inspection, inspection intervals, or 
CDCCLs may be used.

FAA AD Differences

    Note 2: This AD differs from the MCAI and/or service information 
as follows: No differences.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
has the authority to approve AMOCs for this AD, if requested using 
the procedures found in 14 CFR 39.19. Send information to ATTN: Dan 
Rodina, Aerospace Engineer, International Branch, ANM-116, FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 227-2125; fax (425) 227-1149. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in 
this AD, under the provisions of the Paperwork Reduction Act, the 
Office of Management and Budget (OMB) has approved the information 
collection requirements and has assigned OMB Control Number 2120-
0056.

Related Information

    (h) Refer to MCAI Brazilian Airworthiness Directive 2007-05-02, 
effective June 6, 2007, EMBRAER Temporary Revision No. 22-1 of the 
EMB-120 Maintenance Review Board Report (MRBR), dated November 18, 
2005, and Section 6, ``Part D, Critical Design Configuration Control 
Limitations,'' of the EMB-120 MRBR, dated March 22, 2005, for 
related information.

    Issued in Renton, Washington, on October 12, 2007.
Stephen P. Boyd,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service.
[FR Doc. E7-20821 Filed 10-22-07; 8:45 am]
BILLING CODE 4910-13-P