
[Federal Register Volume 76, Number 25 (Monday, February 7, 2011)]
[Proposed Rules]
[Pages 6584-6587]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-2613]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0036; Directorate Identifier 2010-NM-230-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series 
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:

    Bombardier Aerospace has completed a system safety review of the 
aeroplanes fuel system against fuel tank safety standards introduced 
in Chapter 525 of the Airworthiness Manual through Notice of 
Proposed Amendment (NPA) 2002-043 [which corresponds with the FAA's 
Special Federal Aviation Regulation (SFAR) 88]. The identified non-
compliances were then assessed using Transport Canada Policy Letter 
No. 525-001, to determine if mandatory corrective action is 
required.
    The assessment showed that a number of modifications to the fuel 
system are required to mitigate unsafe conditions that could result 
in potential ignition source within the fuel system.

    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 March 24, 2011.

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.
    For service information identified in this proposed AD, contact 
Bombardier, Inc., Q-Series Technical Help Desk, 123 Garratt Boulevard, 
Toronto, Ontario M3K 1Y5, Canada; telephone 416-375-4000; fax 416-375-
4539; e-mail thd.qseries@aero.bombardier.com; Internet http://www.bombardier.com. You may review copies of the referenced service 
information at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington. For information on the availability of 
this material at the FAA, call 425-227-1221.

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: James Delisio, Aerospace Engineer, 
Propulsion and Services Branch, ANE-173, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New 
York 11590; telephone (516) 228-7321; fax (516) 794-5531.

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-2011-0036; 
Directorate Identifier 2010-NM-230-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

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian Airworthiness Directive CF-
2010-31, dated September 3, 2010 (referred to after this as ``the 
MCAI''), to correct an unsafe condition for the specified products. The 
MCAI states:

    Bombardier Aerospace has completed a system safety review of the 
aeroplanes fuel system against fuel tank safety standards introduced 
in Chapter 525 of the Airworthiness Manual through Notice of 
Proposed Amendment (NPA) 2002-043 [which corresponds with the FAA's 
Special Federal Aviation Regulation (SFAR) 88]. The identified non-
compliances were then assessed using Transport Canada Policy Letter 
No. 525-001, to determine if mandatory corrective action is 
required.
    The assessment showed that a number of modifications to the fuel 
system are required to mitigate unsafe conditions that could result 
in potential ignition source within the fuel system.

    The Bombardier modifications include:
     Modsum 4-126330, ``Fuel Tank System Design Left and Right 
Side (SFAR 88) Retrofit.'' The retrofit includes replacing certain 
fittings, couplings, o-rings, gaskets, fuel adapter, and other related 
components with new, improved parts; applying alodine 1132 to certain 
areas of a wing rib and a wing spar; and replacing a certain doubler on 
the front wing spar with a new, improved doubler.
     Modsum 4-126366, ``Fuel Tank System and Fuel Indication--
Wiring Identification, Segregation and

[[Page 6585]]

Installation (High Level Sensor and Fuel Quantity Indication)--
Retrofit.'' The retrofit includes adding new wiring with protective 
sleeving, reworking existing wiring, labeling and separating the fuel 
quantity indicating (FQI) wiring and high level sensor wiring from 
other wiring, enhancing the electro-magnetic interference (EMI) 
shielding of the wiring connected to the vent valve position switch, 
and installing additional provisions (bulkhead brackets) for wiring 
clips in the center fuselage.
     Modsum 4-901425, ``Fuel Feed to APU--Replacement of 
Couplings in Center Wing Left Side--SFAR 88.''
     Modsum 4-126370, ``Fuel Tank System--Enhance Protective 
Covering for Electrical Cable Assembly,'' which includes reworking the 
contact area on the rib at Yw-42.000 to ensure adequate electrical 
bonding, installing spiral wrap on certain cable assemblies where 
existing spiral wrap does not extend 4 inches past the tie mounts, 
applying a dome seal on thread openings on a high level sensor, and 
installing fuel grommets at certain locations.
     Modsum 4-113580, ``Fuel Indication--High Level Sensor--
Application of Sealant to exposed end of Sensor Terminal Block Screws--
Special Inspection and Rectification,'' which includes doing a detailed 
inspection of the high level sensor for correct sealant coverage (`dome 
seal') on the terminal screws, and applying sealant if necessary.
    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

    Bombardier has issued Service Bulletins:
     84-57-09, Revision B, dated September 3, 2008;
     84-28-04, Revision B, dated October 21, 2009;
     84-28-05, dated June 28, 2006;
     84-28-03, Revision C, dated May 15, 2009; and
     84-28-07, dated August 1, 2008.
    Bombardier has also issued Fuel Systems Limitation (FSL) Task 
284000-417 in Section 4-1, Fuel System Limitations, of Part 2--
Airworthiness Limitation Items, Revision 5, dated April 21, 2010, of 
Bombardier Q400 Dash 8 Maintenance Requirements Manual, PSM 1-84-7.
    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 67 products of U.S. registry. We also estimate that 
it would take about 526 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $85 per 
work-hour. Required parts would cost about $37,696 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 $5,521,202, or $82,406 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

[[Page 6586]]

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, Incorporation by 
reference, 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:

Bombardier, Inc.: Docket No. FAA-2011-0036; Directorate Identifier 
2010-NM-230-AD.

Comments Due Date

    (a) We must receive comments by March 24, 2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier, Inc. Model DHC-8-400, -401, 
and -402 airplanes, certificated in any category; with serial 
numbers (S/N) 4003, 4004, 4006, and 4008 through 4205 inclusive.

Subject

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

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:
    Bombardier Aerospace has completed a system safety review of the 
aeroplanes fuel system against fuel tank safety standards introduced 
in Chapter 525 of the Airworthiness Manual through Notice of 
Proposed Amendment (NPA) 2002-043 [which corresponds with the FAA's 
Special Federal Aviation Regulation (SFAR) 88]. The identified non-
compliances were then assessed using Transport Canada Policy Letter 
No. 525-001, to determine if mandatory corrective action is 
required.
    The assessment showed that a number of modifications to the fuel 
system are required to mitigate unsafe conditions that could result 
in potential ignition source within the fuel system.

Compliance

    (f) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Actions Applicable to Airplanes Having S/N 4003, 4004, 4006 & 4008 
Through 4118

    (g) For airplanes having S/Ns 4003, 4004, 4006, and 4008 through 
4118 inclusive: Within 6,000 flight hours after the effective date 
of this AD, incorporate the modifications required in paragraphs 
(g)(1), (g)(2), and (g)(3) of this AD, as applicable.
    (1) Incorporate Bombardier Modsum 4-126330, ``Fuel Tank System 
Design Left and Right Side (SFAR 88) Retrofit,'' by doing all the 
applicable actions in the Accomplishment Instructions of Bombardier 
Service Bulletin 84-57-09, Revision B, dated September 3, 2008.
    (2) Incorporate Bombardier Modsum 4-126366, ``Fuel Tank System 
and Fuel Indication--Wiring Identification, Segregation and 
Installation (High Level Sensor and Fuel Quantity Indication)--
Retrofit,'' by doing all the applicable actions in the 
Accomplishment Instructions of Bombardier Service Bulletin 84-28-04, 
Revision B, dated October 21, 2009.
    (3) For airplanes on which Bombardier Modsum 4-302000, 
``Standard Option--APU Installation,'' has been installed: 
Incorporate Bombardier Modsum 4-901425, ``Fuel Feed to APU--
Replacement of Couplings in Center Wing Left Side--SFAR 88,'' by 
doing all the applicable actions in the Accomplishment Instructions 
of Bombardier Service Bulletin 84-28-05, dated June 28, 2006.
    (h) For airplanes having S/Ns 4003, 4004, 4006, and 4008 through 
4118 inclusive, do Bombardier Fuel System Limitation (FSL) Task 
284000-417 (Functional Check of the Fuel Tank Components and 
Plumbing Lines for Electrical Bonding) contained in Section 4-1, 
Fuel System Limitations, of Part 2--Airworthiness Limitation Items, 
Revision 5, dated April 21, 2010, of Bombardier Q400 Dash 8 
Maintenance Requirements Manual, PSM 1-84-7, at the applicable times 
specified in paragraphs (h)(1) and (h)(2) of this AD. Where the task 
specifies contacting Bombardier for technical assistance, this AD 
requires repairs/rework actions in accordance with a method approved 
by the Manager, New York Aircraft Certification Office (ACO), FAA, 
or Transport Canada Civil Aviation (TCCA) (or its delegated agent).
    (1) Except as provided in paragraphs (h)(1)(i) and (h)(1)(ii) of 
this AD, for airplanes that have incorporated either Bombardier 
Modsum 4-126330 or 4-901425 prior to the effective date of this AD: 
Do Bombardier FSL Task 284000-417 within 6,000 flight hours after 
the effective date of this AD.
    (i) Airplanes on which Bombardier FSL Task 284000-417 was 
successfully completed after incorporation of Bombardier Modsum 4-
126330 or 4-901425 do not need to comply with the requirements of 
paragraph (h) of this AD.
    (ii) Airplanes on which Bombardier Modsum 4-126330 or 4-901425 
was incorporated during manufacturing of the airplane do not need to 
comply with the requirements of paragraph (h) of this AD.
    (2) For airplanes on which neither Bombardier Modsum 4-126330 
nor 4-901425 were incorporated before the effective date of this AD: 
Do Bombardier FSL Task 284000-417 upon completion of the 
incorporation of Bombardier Modsum 4-126330 and, if applicable, 
Bombardier Modsum 4-901425.

Actions Applicable to Airplanes S/N 4003, 4004, 4006 & 4008 Through 
4118 Inclusive, Manufactured Before September 21, 2005

    (i) For airplanes having S/N 4003, 4004, 4006, and 4008 through 
4118 inclusive, on which the date of issuance of the original 
Canadian standard airworthiness certificate or the date of issuance 
of the original Canadian export certificate of airworthiness is 
before September 21, 2005: Within 6,000 flight hours after the 
effective date of this AD, incorporate Bombardier Modsum 4-126370, 
``Fuel Tank System--Enhance Protective Covering for Electrical Cable 
Assembly,'' by doing all the applicable actions in the 
Accomplishment Instructions of Bombardier Service Bulletin 84-28-03, 
Revision C, dated May 15, 2009.

Actions Applicable to Airplanes S/N 4003, 4004, 4006 & 4008 Through 
4118 Inclusive, Manufactured on or After September 21, 2005

    (j) For airplanes having S/Ns 4003, 4004, 4006, and 4008 through 
4118 inclusive, on which the date of issuance of the original 
Canadian standard airworthiness certificate or the date of issuance 
of the original Canadian export certificate of airworthiness is on 
or after September 21, 2005: Within 12,000 flight hours after the 
effective date of this AD, incorporate Bombardier Modsum 4-126370, 
``Fuel Tank System--Enhance Protective Covering for Electrical Cable 
Assembly,'' by doing all the applicable actions in the 
Accomplishment Instructions

[[Page 6587]]

of Bombardier Service Bulletin 84-28-03, Revision C, dated May 15, 
2009.

Actions Applicable to Airplanes S/N 4119 Through 4205 Inclusive

    (k) For airplanes having S/N 4119 through 4205 inclusive: Within 
6,000 flight hours after the effective date of this AD, incorporate 
Bombardier Modsum 4-113580, ``Fuel Indication--High Level Sensor--
Application of Sealant to Exposed End of Sensor Terminal Block 
Screws--Special Inspection and Rectification,'' by doing all the 
applicable actions in the Accomplishment Instructions of Bombardier 
Service Bulletin 84-28-07, dated August 1, 2008.

Credit for Actions Accomplished in Accordance With Previous Service 
Information

    (l) Incorporation of Bombardier Modsum 4-126330 prior to the 
effective date of this AD according to the instructions contained in 
Bombardier Service Bulletin 84-57-09, Revision A, dated March 19, 
2007, meets the requirements of paragraph (g)(1) of this AD.
    (m) Incorporation of Bombardier Modsum 4-126366 prior to the 
effective date of this AD according to the instructions contained in 
Bombardier Service Bulletin 84-28-04, dated June 29, 2006; or 
Revision A, dated November 15, 2006; meets the requirements of 
paragraph (g)(2) of this AD.
    (n) Incorporation of Bombardier Modsum 4-126370 prior to the 
effective date of this AD according to instructions contained in 
Bombardier Service Bulletin 84-28-03, Revision B, dated October 18, 
2006, meets the requirements of paragraphs (i) and (j) of this AD.

FAA AD Differences

    Note 1: This AD differs from the MCAI and/or service information 
as follows: The MCAI specifies to do Bombardier FSL Task 28400-417, 
but does not specify what to do if the functional check finds that 
measured resistance exceeds the specified values. This AD requires 
contacting the Manager, New York ACO, FAA, or TCCA (or its delegated 
agent) for repair/rework instructions.

Other FAA AD Provisions

    (o) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, ANE-
170, New York ACO, 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: Program Manager, Continuing Operational Safety, 
FAA, New York ACO, 1600 Stewart Avenue, Suite 410, Westbury, New 
York 11590; telephone 516-228-7300; fax 516-794-5531. Before using 
any approved AMOC, notify your appropriate principal inspector, or 
lacking a principal inspector, the manager of the local flight 
standards district office/certificate holding district office. The 
AMOC approval letter must specifically reference this AD.
    (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.

Related Information

    (p) Refer to MCAI Canadian Airworthiness Directive CF-2010-31, 
dated September 3, 2010; Bombardier Task 284000-417 in Section 4-1, 
Fuel System Limitations, of Part 2--Airworthiness Limitation Items, 
Revision 5, dated April 21, 2010, of Bombardier Q400 Dash 8 
Maintenance Requirements Manual, PSM 1-84-7; and the Bombardier 
service bulletins identified in Table 1 of this AD; for related 
information.

                                      Table 1--Relevant Service Information
----------------------------------------------------------------------------------------------------------------
     Bombardier Service Bulletin--               Revision--                            Dated--
----------------------------------------------------------------------------------------------------------------
84-28-03...............................  C.........................  May 15, 2009.
84-28-04...............................  B.........................  October 21, 2009.
84-28-05...............................  Original..................  June 28, 2006.
84-28-07...............................  Original..................  August 1, 2008.
84-57-09...............................  B.........................  September 3, 2008.
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    Dated: Issued in Renton, Washington, on January 31, 2011.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-2613 Filed 2-4-11; 8:45 am]
BILLING CODE 4910-13-P


