Airworthiness Directives; Bombardier Model CL-600-2C10 (Regional Jet Series 700, 701 & 702) Airplanes and Model CL-600-2D24 (Regional Jet Series 900) Airplanes, 54749-54751 [E8-22218]
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Federal Register / Vol. 73, No. 185 / Tuesday, September 23, 2008 / Proposed Rules
accordance with the procedures found in 14
CFR 39.19.
(2) To request a different method of
compliance or a different compliance time
for this AD, follow the procedures in 14 CFR
39.19. 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.
DEPARTMENT OF TRANSPORTATION
We must receive comments on
this proposed AD by October 23, 2008.
ADDRESSES: You may send comments by
any of the following methods:
• Federal eRulemaking Portal: Go to
https://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.
Federal Aviation Administration
Examining the AD Docket
Issued in Renton, Washington, on
September 11, 2008.
Michael Kaszycki,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
[FR Doc. E8–22220 Filed 9–22–08; 8:45 am]
BILLING CODE 4910–13–P
14 CFR Part 39
[Docket No. FAA–2008–1007; Directorate
Identifier 2008–NM–135–AD]
RIN 2120–AA64
Airworthiness Directives; Bombardier
Model CL–600–2C10 (Regional Jet
Series 700, 701 & 702) Airplanes and
Model CL–600–2D24 (Regional Jet
Series 900) Airplanes
Federal Aviation
Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking
(NPRM).
jlentini on PROD1PC65 with PROPOSALS
AGENCY:
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
CL–600–2C10/CL–600–2D24 aircraft
fuel system against new fuel tank safety
standards. The assessment showed that
due to the close proximity of
intrinsically safe fuel system wiring
with other wiring, a single failure from
wire chafing at various locations of the
fuselage could result in an ignition
source inside the fuel tank. In addition,
chafing of the temperature sensor wiring
against the high power wiring in the
avionics compartment could lead to
overheating of the temperature sensor
and hot surface ignition. The presence
of an ignition source inside the fuel tank
could result in a fuel tank explosion.
The proposed AD would require
actions that are intended to address the
unsafe condition described in the MCAI.
VerDate Aug<31>2005
16:39 Sep 22, 2008
Jkt 214001
DATES:
You may examine the AD docket on
the Internet at https://
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:
Rocco Viselli, Aerospace Engineer,
Airframe and Propulsion Branch, ANE–
171, FAA, New York Aircraft
Certification Office, 1600 Stewart
Avenue, Suite 410, Westbury, New York
11590; telephone (516) 228–7331; 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–2008–1007; Directorate Identifier
2008–NM–135–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 https://
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.
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Fmt 4702
Sfmt 4702
54749
Discussion
Transport Canada Civil Aviation
(TCCA), which is the aviation authority
for Canada, has issued Canadian
Airworthiness Directive CF–2008–25,
dated July 3, 2008 (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 CL–600–2C10/
CL–600–2D24 aircraft fuel system against
new fuel tank safety standards, introduced in
Chapter 525 of the Airworthiness Manual
through Notice of Proposed Amendment
(NPA) 2002–043. The identified noncompliances were assessed using Transport
Canada Policy Letter No. 525–001 to
determine if mandatory corrective action was
required.
The assessment showed that due to the
close proximity of intrinsically safe fuel
system wiring with other wiring, a single
failure from wire chafing at various locations
of the fuselage could result in an ignition
source inside the fuel tank. In addition,
chafing of the temperature sensor wiring
against the high power wiring in the avionics
compartment could lead to overheating of the
temperature sensor and hot surface ignition.
The presence of an ignition source inside the
fuel tank could result in a fuel tank
explosion.
To correct the unsafe condition, this
directive mandates the installation of conduit
and the addition of spacers to protect fuel
tank wiring.
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
E:\FR\FM\23SEP1.SGM
23SEP1
54750
Federal Register / Vol. 73, No. 185 / Tuesday, September 23, 2008 / Proposed Rules
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
Bulletin 670BA–24–011, Revision C,
dated November 28, 2005. The actions
described in this service information are
intended to correct the unsafe condition
identified in the MCAI.
jlentini on PROD1PC65 with PROPOSALS
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
VerDate Aug<31>2005
16:39 Sep 22, 2008
Jkt 214001
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 159 products of U.S.
registry. We also estimate that it would
take about 38 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 $2,914 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
$946,686, or $5,954 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.
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Fmt 4702
Sfmt 4702
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.
§ 39.13
[Amended]
2. The FAA amends § 39.13 by adding
the following new AD:
Bombardier, Inc. (Formerly Canadair):
Docket No. FAA–2008–1007; Directorate
Identifier 2008–NM–135–AD.
Comments Due Date
(a) We must receive comments by October
23, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to the airplanes
identified in paragraphs (c)(1) and (c)(2) of
this AD, certificated in any category.
(1) Bombardier Model CL–600–2C10
(Regional Jet Series 700, 701, & 702)
airplanes, serial numbers 10003 through
10169 inclusive.
(2) Bombardier Model CL–600–2D24
(Regional Jet Series 900) airplanes, serial
numbers 15001 through 15030 inclusive.
Subject
(d) Air Transport Association (ATA) of
America Code 24: Electrical Power.
Reason
(e) The mandatory continuing
airworthiness information (MCAI) states:
Bombardier Aerospace has completed a
system safety review of the CL–600–2C10/
CL–600–2D24 aircraft fuel system against
new fuel tank safety standards, introduced in
Chapter 525 of the Airworthiness Manual
through Notice of Proposed Amendment
E:\FR\FM\23SEP1.SGM
23SEP1
Federal Register / Vol. 73, No. 185 / Tuesday, September 23, 2008 / Proposed Rules
(NPA) 2002–043. The identified noncompliances were assessed using Transport
Canada Policy Letter No. 525–001 to
determine if mandatory corrective action was
required.
The assessment showed that due to the
close proximity of intrinsically safe fuel
system wiring with other wiring, a single
failure from wire chafing at various locations
of the fuselage could result in an ignition
source inside the fuel tank. In addition,
chafing of the temperature sensor wiring
against the high power wiring in the avionics
compartment could lead to overheating of the
temperature sensor and hot surface ignition.
The presence of an ignition source inside the
fuel tank could result in a fuel tank
explosion.
To correct the unsafe condition, this
directive mandates the installation of conduit
and the addition of spacers to protect fuel
tank wiring.
Actions and Compliance
(f) Unless already done, do the following
actions.
(1) Within 4,500 flight hours after the
effective date of this AD, modify the fuel
system wiring along the fuselage and in the
avionics compartment by installing
protective conduit and spacers, in
accordance with the Accomplishment
Instructions of Bombardier Service Bulletin
670BA–24–011, Revision C, dated November
28, 2005.
(2) Actions done before the effective date
of this AD in accordance with Bombardier
Service Bulletin 670BA–24–011, dated
September 7, 2004; Revision A, dated
December 14, 2004; or Revision B, dated
February 28, 2005; are acceptable for
compliance with the corresponding
requirements of this AD.
FAA AD Differences
jlentini on PROD1PC65 with PROPOSALS
Note: 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, New York Aircraft
Certification Office (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: Rocco
Viselli, Aerospace Engineer, Airframe and
Propulsion Branch, ANE–171, FAA, New
York ACO, 1600 Stewart Avenue, Suite 410,
Westbury, New York 11590; telephone (516)
228–7331; fax (516) 794–5531. 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 FAAapproved 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.
VerDate Aug<31>2005
16:39 Sep 22, 2008
Jkt 214001
(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.
54751
result in inability of the structure to
carry horizontal stabilizer flight loads,
and loss of controllability of the
airplane.
[Docket No. FAA–2008–0981; Directorate
Identifier 2008–NM–073–AD]
We must receive comments on
this proposed AD by November 7, 2008.
ADDRESSES: You may send comments by
any of the following methods:
• Federal eRulemaking Portal: Go to
https://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
W12–140, 1200 New Jersey Avenue, SE.,
Washington, DC 20590, between 9 a.m.
and 5 p.m., Monday through Friday,
except Federal holidays.
For service information identified in
this AD, contact Boeing Commercial
Airplanes, P.O. Box 3707, Seattle,
Washington 98124–2207.
RIN 2120–AA64
Examining the AD Docket
Airworthiness Directives; Boeing
Model 747 Airplanes
You may examine the AD docket on
the Internet at https://
www.regulations.gov; or in person at the
Docket Management Facility 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 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: Ivan
Li, Aerospace Engineer, Airframe
Branch, ANM–120S, FAA, Seattle
Aircraft Certification Office, 1601 Lind
Avenue, SW., Renton, Washington
98057–3356; telephone (425) 917–6437;
fax (425) 917–6590.
SUPPLEMENTARY INFORMATION:
Related Information
(h) Refer to MCAI Canadian Airworthiness
Directive CF–2008–25, dated July 3, 2008,
and Bombardier Service Bulletin 670BA–24–
011, Revision C, dated November 28, 2005,
for related information.
Issued in Renton, Washington, on
September 12, 2008.
Michael Kaszycki,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
[FR Doc. E8–22218 Filed 9–22–08; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking
(NPRM).
AGENCY:
SUMMARY: The FAA proposes to
supersede an existing airworthiness
directive (AD) that applies to certain
Boeing Model 747 airplanes. The
existing AD currently requires repetitive
inspections of the body station (BS)
2598 bulkhead, and corrective actions if
necessary. The existing AD also
currently requires a terminating
modification for the repetitive
inspections and a post-modification
inspection of the modified area. This
proposed AD would continue requiring
those actions with revised service
information. For certain airplanes, this
proposed AD would require new
repetitive inspections, an interim
modification, and post-interim
modification inspections. For certain
airplanes, this proposed AD also would
require replacing any previously
repaired aft inner chord and reinstalling
the terminating modification. This
proposed AD results from reports of
cracked aft inner chords on airplanes
after certain requirements of the existing
AD were done. We are proposing this
AD to prevent fatigue cracking of the BS
2598 bulkhead structure, which could
PO 00000
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Fmt 4702
Sfmt 4702
DATES:
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–2008–0981; Directorate Identifier
2008–NM–073–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
E:\FR\FM\23SEP1.SGM
23SEP1
]]>Agencies
[Federal Register Volume 73, Number 185 (Tuesday, September 23, 2008)]
[Proposed Rules]
[Pages 54749-54751]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-22218]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-1007; Directorate Identifier 2008-NM-135-AD]
RIN 2120-AA64
Airworthiness Directives; Bombardier Model CL-600-2C10 (Regional
Jet Series 700, 701 & 702) Airplanes and Model CL-600-2D24 (Regional
Jet Series 900) Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
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 CL-600-2C10/CL-600-2D24 aircraft fuel system against new fuel
tank safety standards. The assessment showed that due to the close
proximity of intrinsically safe fuel system wiring with other wiring, a
single failure from wire chafing at various locations of the fuselage
could result in an ignition source inside the fuel tank. In addition,
chafing of the temperature sensor wiring against the high power wiring
in the avionics compartment could lead to overheating of the
temperature sensor and hot surface ignition. The presence of an
ignition source inside the fuel tank could result in a fuel tank
explosion.
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 23,
2008.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to https://
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 https://
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: Rocco Viselli, Aerospace Engineer,
Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New
York 11590; telephone (516) 228-7331; 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-2008-1007;
Directorate Identifier 2008-NM-135-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 https://
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-
2008-25, dated July 3, 2008 (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
CL-600-2C10/CL-600-2D24 aircraft fuel system against new fuel tank
safety standards, introduced in Chapter 525 of the Airworthiness
Manual through Notice of Proposed Amendment (NPA) 2002-043. The
identified non-compliances were assessed using Transport Canada
Policy Letter No. 525-001 to determine if mandatory corrective
action was required.
The assessment showed that due to the close proximity of
intrinsically safe fuel system wiring with other wiring, a single
failure from wire chafing at various locations of the fuselage could
result in an ignition source inside the fuel tank. In addition,
chafing of the temperature sensor wiring against the high power
wiring in the avionics compartment could lead to overheating of the
temperature sensor and hot surface ignition. The presence of an
ignition source inside the fuel tank could result in a fuel tank
explosion.
To correct the unsafe condition, this directive mandates the
installation of conduit and the addition of spacers to protect fuel
tank wiring.
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
[[Page 54750]]
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 Bulletin 670BA-24-011, Revision C,
dated November 28, 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 159 products of U.S. registry. We also estimate that
it would take about 38 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 $2,914 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 $946,686, or $5,954 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:
Bombardier, Inc. (Formerly Canadair): Docket No. FAA-2008-1007;
Directorate Identifier 2008-NM-135-AD.
Comments Due Date
(a) We must receive comments by October 23, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to the airplanes identified in paragraphs
(c)(1) and (c)(2) of this AD, certificated in any category.
(1) Bombardier Model CL-600-2C10 (Regional Jet Series 700, 701,
& 702) airplanes, serial numbers 10003 through 10169 inclusive.
(2) Bombardier Model CL-600-2D24 (Regional Jet Series 900)
airplanes, serial numbers 15001 through 15030 inclusive.
Subject
(d) Air Transport Association (ATA) of America Code 24:
Electrical Power.
Reason
(e) The mandatory continuing airworthiness information (MCAI)
states:
Bombardier Aerospace has completed a system safety review of the
CL-600-2C10/CL-600-2D24 aircraft fuel system against new fuel tank
safety standards, introduced in Chapter 525 of the Airworthiness
Manual through Notice of Proposed Amendment
[[Page 54751]]
(NPA) 2002-043. The identified non-compliances were assessed using
Transport Canada Policy Letter No. 525-001 to determine if mandatory
corrective action was required.
The assessment showed that due to the close proximity of
intrinsically safe fuel system wiring with other wiring, a single
failure from wire chafing at various locations of the fuselage could
result in an ignition source inside the fuel tank. In addition,
chafing of the temperature sensor wiring against the high power
wiring in the avionics compartment could lead to overheating of the
temperature sensor and hot surface ignition. The presence of an
ignition source inside the fuel tank could result in a fuel tank
explosion.
To correct the unsafe condition, this directive mandates the
installation of conduit and the addition of spacers to protect fuel
tank wiring.
Actions and Compliance
(f) Unless already done, do the following actions.
(1) Within 4,500 flight hours after the effective date of this
AD, modify the fuel system wiring along the fuselage and in the
avionics compartment by installing protective conduit and spacers,
in accordance with the Accomplishment Instructions of Bombardier
Service Bulletin 670BA-24-011, Revision C, dated November 28, 2005.
(2) Actions done before the effective date of this AD in
accordance with Bombardier Service Bulletin 670BA-24-011, dated
September 7, 2004; Revision A, dated December 14, 2004; or Revision
B, dated February 28, 2005; are acceptable for compliance with the
corresponding requirements of this AD.
FAA AD Differences
Note: 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, New
York Aircraft Certification Office (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: Rocco Viselli, Aerospace
Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York
ACO, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590;
telephone (516) 228-7331; fax (516) 794-5531. 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 Canadian Airworthiness Directive CF-2008-25,
dated July 3, 2008, and Bombardier Service Bulletin 670BA-24-011,
Revision C, dated November 28, 2005, for related information.
Issued in Renton, Washington, on September 12, 2008.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-22218 Filed 9-22-08; 8:45 am]
BILLING CODE 4910-13-P
