

[Federal Register: December 17, 2007 (Volume 72, Number 241)]
[Proposed Rules]               
[Page 71286-71289]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17de07-23]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0334; Directorate Identifier 2007-NM-206-AD]
RIN 2120-AA64

 
Airworthiness Directives; ATR Model ATR42 and ATR72 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:

    [T]he FAA has published a set of new rules related to the fuel 
tank safety, including the Special Federal Aviation Regulation 88 
(SFAR 88).
    The JAA (Joint Aviation Authority) has issued an Interim Policy 
JAA INT/POL 25/12, to recommend the application of a similar 
requirement to the National Aviation Authorities (NAA) [of Europe].
* * * * *
    * * * ATR carried out a safety review on the fuel tank systems 
and zones adjacent to the fuel tanks on all ATR models * * *.
* * * * *
The unsafe condition is 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. 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 January 16, 
2008.

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

[[Page 71287]]

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: Tom Rodriguez, Aerospace Engineer, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
227-1137; 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-2007-0334; 
Directorate Identifier 2007-NM-206-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 European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Community, has issued EASA 
Airworthiness Directive 2007-0226, dated August 24, 2006 (referred to 
after this as ``the MCAI''), to correct an unsafe condition for the 
specified products. The MCAI states:

    [T]he FAA has published a set of new rules related to the fuel 
tank safety, including the Special Federal Aviation Regulation 88 
(SFAR 88).
    The JAA (Joint Aviation Authority) has issued an Interim Policy 
JAA INT/POL 25/12, to recommend the application of a similar 
requirement to the National Aviation Authorities (NAA) [of Europe].
    This recommendation was followed by French DGAC, which rendered 
the compliance to JAA INT/POL 25/12 mandatory for all ATR Aircraft.
    Under this regulation, all holders of type certificates are 
required to conduct a design review of their fuel tank systems 
against explosion risk. It also requires the development and 
implementation of maintenance and inspection instructions to 
maintain the safety of the fuel tank system. To answer JAA INT/POL 
25/12, and in accordance with SFAR 88 requirements and guideline, 
ATR carried out a safety review on the fuel tank systems and zones 
adjacent to the fuel tanks on all ATR models using relevant safety 
assessment methods of JAR 35.1309.
    As a result of this safety review, ATR developed for ATR 42 the 
modification 05355 (SB (service bulletin) ATR42-28-0039), and for 
ATR 72 the modification 05356 (SB ATR72-28-1019). Those 
modifications consist in the installation of fuses adapters on 
wiring entering the fuel tanks and current limitation devices. For 
ATR 72 aircraft, the modification also requires replacement of the 
high level sensors with new sensors having shorter harness.

The modification also includes related investigative and corrective 
actions, which include inspecting the electrical harness for correct 
installation and adjusting the harness as necessary, and, for Model 
ATR42 airplanes, inspecting the bonding strap for correct installation 
and adjusting the bonding strap. 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.
    The Joint Aviation Authorities (JAA) has issued a regulation that 
is similar to SFAR 88. (The JAA is an associated body of the European 
Civil Aviation Conference (ECAC) representing the civil aviation 
regulatory authorities of a number of European States who have agreed 
to co-operate in developing and implementing common safety regulatory 
standards and procedures.) Under this regulation, the JAA stated that 
all members of the ECAC that hold type certificates for transport 
category airplanes are required to conduct a design review against 
explosion risks.
    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

    ATR has issued Service Bulletins ATR42-28-0039, Revision 04, dated 
June 12, 2007; and ATR72-28-1019, Revision 05, dated June 12, 2007. 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

[[Page 71288]]

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 55 products of U.S. registry. We also estimate that 
it would take about 150 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $80 per 
work-hour. Required parts would cost about $23,000 per product. Where 
the service information lists required parts costs that are covered 
under warranty, we have assumed that there will be no charge for these 
costs. As we do not control warranty coverage for affected parties, 
some parties may incur costs higher than estimated here. Based on these 
figures, we estimate the cost of the proposed AD on U.S. operators to 
be $1,925,000, or $35,000 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.
    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:

ATR-GIE Avions De Transport R[eacute]gional (Formerly Aerospatiale): 
Docket No. FAA-2007-0334; Directorate Identifier 2007-NM-206-AD.

Comments Due Date

    (a) We must receive comments by January 16, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to the airplanes specified in paragraphs 
(c)(1) and (c)(2) of this AD.
    (1) ATR Model ATR42-200, -300, -320, and -500 airplanes, 
certificated in any category, serial numbers 1 through 642.
    (2) ATR Model ATR72-101, -201, -102, -202, -211, -212, and -212A 
airplanes, certificated in any category, serial numbers 1 through 
724.

Subject

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

Reason

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

    [T]he FAA has published a set of new rules related to the fuel 
tank safety, including the Special Federal Aviation Regulation 88 
(SFAR 88).
    The JAA (Joint Aviation Authority) has issued an Interim Policy 
JAA INT/POL 25/12, to recommend the application of a similar 
requirement to the National Aviation Authorities (NAA) [of Europe].
    This recommendation was followed by French DGAC, which rendered 
the compliance to JAA INT/POL 25/12 mandatory for all ATR Aircraft.
    Under this regulation, all holders of type certificates are 
required to conduct a design review of their fuel tank systems 
against explosion risk. It also requires the development and 
implementation of maintenance and inspection instructions to 
maintain the safety of the fuel tank system. To answer JAA INT/POL 
25/12, and in accordance with SFAR 88 requirements and guidelines, 
ATR carried out a safety review on the fuel tank systems and zones 
adjacent to the fuel tanks on all ATR models using relevant safety 
assessment methods of JAR 35.1309.
    As a result of this safety review, ATR developed for ATR 42 the 
modification 05355 (SB (service bulletin) ATR42-28-0039), and for 
ATR 72 the modification 05356 (SB ATR72-28-1019). Those 
modifications consist in the installation of fuses adapters on 
wiring entering the fuel tanks and current limitation devices. For 
ATR 72 aircraft, the modification also requires replacement of the 
high level sensors with new sensors having shorter harness.

The modification also includes related investigative and corrective 
actions, which include inspecting the electrical harness for correct 
installation and adjusting the harness as necessary, and, for Model 
ATR42 airplanes, inspecting the bonding strap for correct 
installation and adjusting the bonding strap. The unsafe condition 
is 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.

Actions and Compliance

    (f) Within 41 months after the effective date of this AD, unless 
already done, modify the fuel system and do all applicable related 
investigative and corrective actions according to the instructions 
given by the applicable service bulletin listed in Table 1 of this 
AD. Do all applicable related investigative and corrective actions 
before further flight.

[[Page 71289]]

Actions accomplished before the effective date of this AD in 
accordance with Avions de Transport Regional Service Bulletin ATR42-
28-0039, Revision 03, dated November 15, 2006, are considered 
acceptable for compliance with the corresponding action specified in 
this AD.

                      Table 1.--Service Information
------------------------------------------------------------------------
  Avions de Transport Regional
        Service Bulletin          Revision level           Date
------------------------------------------------------------------------
ATR42-28-0039 (for Model ATR42               04   June 12, 2007.
 Airplanes).
ATR72-28-1019 (for Model ATR72               05   June 12, 2007.
 Airplanes).
------------------------------------------------------------------------

FAA AD Differences

    Note: This AD differs from the MCAI and/or service information 
as follows: The additional actions specified in the MCAI for 
operators that have done actions in accordance with previous issues 
of the service bulletins are not complete. Therefore, this AD only 
refers to ATR Service Bulletin ATR42-28-0039, Revision 03, dated 
November 15, 2006; Revision 04, dated June 12, 2007; and ATR72-28-
1019, Revision 05, dated June 12, 2007; as appropriate sources of 
service information for accomplishing the required actions. 
Operators that have done actions in accordance with previous issues 
of the service bulletins may request an approval for an alternative 
method of compliance (AMOC) according to paragraph (g) of this AD, 
provided that the AMOC provides an acceptable level of safety.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, ANM-
116, International Branch, 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: Tom 
Rodriguez, Aerospace Engineer, International Branch, ANM-116, 
Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 227-1137; 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 EASA Airworthiness Directive 2007-0226, dated 
August 24, 2007, and the service information listed in Table 2 of 
this AD, for related information.

                  Table 2.--Related Service Information
------------------------------------------------------------------------
  Avions de Transport Regional
        Service Bulletin          Revision level           Date
------------------------------------------------------------------------
ATR42-28-0039..................              04   June 12, 2007.
ATR72-28-1019..................              05   June 12, 2007.
------------------------------------------------------------------------


    Issued in Renton, Washington, on December 10, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-24382 Filed 12-14-07; 8:45 am]

BILLING CODE 4910-13-P
