

[Federal Register: September 19, 2007 (Volume 72, Number 181)]
[Proposed Rules]               
[Page 53501-53504]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19se07-26]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-29248; Directorate Identifier 2007-NM-155-AD]
RIN 2120-AA64

 
Airworthiness Directives; Saab Model SAAB-Fairchild SF340A (SAAB/
SF340A) and SAAB 340B 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:

    Subsequent to accidents involving Fuel Tank System explosions in 
flight * * * and on ground, * * * Special Federal Aviation 
Regulation 88 (SFAR88) * * * required a safety review of the 
aircraft Fuel Tank System * * *.
* * * * *

[[Page 53502]]

    Fuel Airworthiness Limitations are items arising from a systems 
safety analysis that have been shown to have failure mode(s) 
associated with an `unsafe condition' * * *. These are identified in 
Failure Conditions for which an unacceptable probability of ignition 
risk could exist if specific tasks and/or practices are not 
performed in accordance with the manufacturers' requirements.

    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 October 19, 
2007.

ADDRESSES: You may send comments by any of the following methods:
     DOT Docket Web Site: Go to http://dms.dot.gov and follow 

the instructions for sending your comments electronically.
     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: Room W12-140 on the ground floor of the 
West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
     Federal eRulemaking Portal: http://www.regulations.gov. 

Follow the instructions for submitting comments.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://dms.dot.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: Mike Borfitz, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, WA 98057-3356; telephone (425) 227-2677; 
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-
29248; Directorate Identifier 2007-NM-155-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://dms.dot.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 2006-0221, dated July 20, 2006 (referred to 
after this as ``the MCAI''), to correct an unsafe condition for the 
specified products. The MCAI states:

    Subsequent to accidents involving Fuel Tank System explosions in 
flight * * * and on ground, the FAA published Special Federal 
Aviation Regulation 88 (SFAR 88) in June 2001. SFAR 88 required a 
safety review of the aircraft Fuel Tank System to determine that the 
design meets the requirements of FAR (Federal Aviation Regulation) 
Sec.  25.901 and Sec.  25.981(a) and (b).
    A similar regulation has been recommended by the JAA (Joint 
Aviation Authorities) to the European National Aviation Authorities 
in JAA letter 04/00/02/07/03-L024 of 3 February 2003. The review was 
requested to be mandated by NAA's (National Aviation Authorities) 
using JAR (Joint Aviation Regulation) Sec.  25.901(c), Sec.  
25.1309.
    In August 2005 EASA published a policy statement on the process 
for developing instructions for maintenance and inspection of Fuel 
Tank System ignition source prevention (EASA D 2005/CPRO, http://www.easa.eu.int/home/cert_policy_statements_en.html
) that also 

included the EASA expectations with regard to compliance times of 
the corrective actions on the unsafe and the not unsafe part of the 
harmonised design review results. On a global scale the TC (type 
certificate) holders committed themselves to the EASA published 
compliance dates (see EASA policy statement). The EASA policy 
statement has been revised in March 2006: The date of 31-12-2005 for 
the unsafe related actions has now been set at 01-07-2006.
    Fuel Airworthiness Limitations are items arising from a systems 
safety analysis that have been shown to have failure mode(s) 
associated with an `unsafe condition' as defined in FAA's memo 2003-
112-15 `SFAR 88--Mandatory Action Decision Criteria'. These are 
identified in Failure Conditions for which an unacceptable 
probability of ignition risk could exist if specific tasks and/or 
practices are not performed in accordance with the manufacturers' 
requirements.
    This EASA Airworthiness Directive mandates the Fuel System 
Airworthiness Limitations (comprising maintenance/inspection tasks 
and Critical Design Configuration Control Limitations (CDCCL)) for 
the type of aircraft, that resulted from the design reviews and the 
JAA recommendation and EASA policy statement mentioned above.

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

[[Page 53503]]

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

    Saab has issued Saab 340 Fuel Airworthiness Limitations Document 
340 LKS 009033, dated February 14, 2006. 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 144 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 $11,520, 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.
    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:

SAAB Aircraft AB: Docket No. FAA-2007-29248; Directorate Identifier 
2007-NM-155-AD.

Comments Due Date

    (a) We must receive comments by October 19, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Saab Model SAAB-Fairchild SF340A 
(SAAB/SF340A) and SAAB 340B airplanes, certificated in any category, 
all serial numbers.

    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.

Subject

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

Reason

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

    Subsequent to accidents involving Fuel Tank System explosions in 
flight * * * and on ground, the FAA published Special Federal 
Aviation Regulation 88 (SFAR 88) in June 2001. SFAR 88 required a 
safety review of the aircraft Fuel Tank System to determine that the 
design meets the requirements of FAR (Federal Aviation Regulation) 
Sec.  25.901 and Sec.  25.981(a) and (b).
    A similar regulation has been recommended by the JAA (Joint 
Aviation Authorities) to the European National Aviation Authorities 
in JAA letter 04/00/02/07/03-L024 of 3 February 2003. The review

[[Page 53504]]

was requested to be mandated by NAA's (National Aviation 
Authorities) using JAR (Joint Aviation Regulation) Sec.  25.901(c), 
Sec.  25.1309.
    In August 2005 EASA published a policy statement on the process 
for developing instructions for maintenance and inspection of Fuel 
Tank System ignition source prevention (EASA D 2005/CPRO, http://www.easa.eu.int/home/cert_policy_statements_en.html
) that also 

included the EASA expectations with regard to compliance times of 
the corrective actions on the unsafe and the not unsafe part of the 
harmonised design review results. On a global scale the TC (type 
certificate) holders committed themselves to the EASA published 
compliance dates (see EASA policy statement). The EASA policy 
statement has been revised in March 2006: The date of 31-12-2005 for 
the unsafe related actions has now been set at 01-07-2006.
    Fuel Airworthiness Limitations are items arising from a systems 
safety analysis that have been shown to have failure mode(s) 
associated with an ``unsafe condition'' as defined in FAA's memo 
2003-112-15 ``SFAR 88--Mandatory Action Decision Criteria''. These 
are identified in Failure Conditions for which an unacceptable 
probability of ignition risk could exist if specific tasks and/or 
practices are not performed in accordance with the manufacturers' 
requirements.
    This EASA Airworthiness Directive mandates the Fuel System 
Airworthiness Limitations (comprising maintenance/inspection tasks 
and Critical Design Configuration Control Limitations (CDCCL)) for 
the type of aircraft, that resulted from the design reviews and the 
JAA recommendation and EASA policy statement mentioned above.

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 3 months after the effective date of this AD, revise 
the Airworthiness Limitations Section (ALS) of the Instructions for 
Continued Airworthiness to incorporate the maintenance and 
inspection instructions in Part 1 of Saab 340 Fuel Airworthiness 
Limitations Document 340 LKS 009033, dated February 14, 2006. For 
all tasks identified in Part 1 of Saab 340 Fuel Airworthiness 
Limitations Document 340 LKS 009033, dated February 14, 2006, the 
initial compliance times start from the effective date of this AD, 
and the repetitive inspections must be accomplished thereafter at 
the interval specified in Part 1 of Saab 340 Fuel Airworthiness 
Limitations Document 340 LKS 009033, dated February 14, 2006.
    (2) Within 12 months after the effective date of this AD, revise 
the ALS of the Instructions for Continued Airworthiness to 
incorporate the CDCCLs as defined in Part 2 of Saab 340 Fuel 
Airworthiness Limitations Document 340 LKS 009033, dated February 
14, 2006.
    (3) 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.
    (4) Where Saab 340 Fuel Airworthiness Limitations Document 340 
LKS 009033, dated February 14, 2006, allows for exceptional short-
term extensions, an exception is acceptable to the FAA if it is 
approved by the appropriate principal inspector in the FAA Flight 
Standards Certificate Holding District Office.

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: Mike 
Borfitz, Aerospace Engineer, International Branch, ANM-116, FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 227-2677; 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 European Aviation Safety Agency (EASA) 
Airworthiness Directive 2006-0221, dated July 20, 2006, and Saab 340 
Fuel Airworthiness Limitations Document 340 LKS 009033, dated 
February 14, 2006, for related information.

    Issued in Renton, Washington, on September 10, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-18478 Filed 9-18-07; 8:45 am]

BILLING CODE 4910-13-P
