Airworthiness Directives; Bombardier Model CL-600-2C10 (Regional Jet Series 700, 701 & 702) Airplanes and Model CL-600-2D24 (Regional Jet Series 900) Airplanes, 63094-63096 [E8-25309]

Download as PDF 63094 Federal Register / Vol. 73, No. 206 / Thursday, October 23, 2008 / Proposed Rules Issued in Burlington, Massachusetts, on October 16, 2008. Peter A. White, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. E8–25278 Filed 10–22–08; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2008–1115; Directorate Identifier 2008–NM–134–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). 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: dwashington3 on PRODPC61 with PROPOSALS Bombardier Aerospace has completed a system safety review of the CL–600–2C10/ CL–600–SD24 aircraft fuel system against the new fuel tank safety standards. * * * The assessment showed that a single failure due to chafing of fuel system wiring with high power wiring at the centre fuel tank front spar could result in overheating of the fuel boost pump. The assessment also showed that chafing of the high power wiring with the centre fuel tank front spar structures could result in overheating of the fuel tank wall. Overheating of the fuel tank wall could lead to hot surface ignition resulting 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 November 24, 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 VerDate Aug<31>2005 14:57 Oct 22, 2008 Jkt 217001 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, 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–2008–1115; Directorate Identifier 2008–NM–134–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–2008–24, 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/ PO 00000 Frm 00011 Fmt 4702 Sfmt 4702 CL–600–2D24 aircraft fuel system against the 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 a single failure due to chafing of fuel system wiring with high power wiring at the centre fuel tank front spar could result in overheating of the fuel boost pump. The assessment also showed that chafing of the high power wiring with the centre fuel tank front spar structures could result in overheating of the fuel tank wall. Overheating of the fuel tank wall could lead to hot surface ignition resulting in a fuel tank explosion. To correct the unsafe condition, this directive mandates separation of the high power wiring from the fuel system wiring at the centre fuel tank front spar area and the installation of additional clamping and support for the high power wiring [i.e., modifying the routing and support of electrical wires in the centre fuel tank front spar area]. Required actions also include an inspection to determine if pins have a minimum of one thread above the nuts, and a visual inspection for damage of the sealant. Corrective actions include replacing pins and nuts and applying sealant. 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 E:\FR\FM\23OCP1.SGM 23OCP1 Federal Register / Vol. 73, No. 206 / Thursday, October 23, 2008 / Proposed Rules 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–24–012, Revision B, dated July 25, 2007. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI. dwashington3 on PRODPC61 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 these changes, we do not intend to differ substantively from the information VerDate Aug<31>2005 14:57 Oct 22, 2008 Jkt 217001 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 102 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 $7,646 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 $2,513,154, or $15,806 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: PO 00000 Frm 00012 Fmt 4702 Sfmt 4702 63095 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. § 39.13 [Amended] 2. The FAA amends § 39.13 by adding the following new AD: Bombardier Inc. (Formerly Canadair): Docket No. FAA–2008–1115; Directorate Identifier 2008–NM–134–AD. Comments Due Date (a) We must receive comments by November 24, 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 the new fuel tank safety standards, introduced in Chapter 525 of the Airworthiness Manual through Notice of Proposed Amendment (NPA) 2002–043. The identified non- E:\FR\FM\23OCP1.SGM 23OCP1 63096 Federal Register / Vol. 73, No. 206 / Thursday, October 23, 2008 / Proposed Rules compliances were assessed using Transport Canada Policy Letter No. 525–001 to determine if mandatory corrective action was required. The assessment showed that a single failure due to chafing of fuel system wiring with high power wiring at the center fuel tank front spar could result in overheating of the fuel boost pump. The assessment also showed that chafing of the high power wiring with the centre fuel tank front spar structures could result in overheating of the fuel tank wall. Overheating of the fuel tank wall could lead to hot surface ignition resulting in a fuel tank explosion. To correct the unsafe condition, this directive mandates separation of the high power wiring from the fuel system wiring at the centre fuel tank front spar area and the installation of additional clamping and support for the high power wiring [i.e., modifying the routing and support of electrical wires in the center fuel tank front spar area]. Required actions also include an inspection to determine if pins have a minimum of one thread above the nuts, and a visual inspection for damage of the sealant. Corrective actions include replacing pins and nuts and applying sealant. 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 routing and support of the electrical wires in the center fuel tank front spar area (including an inspection to determine if pins have a minimum of one thread above the nuts, and a visual inspection for damage of the sealant, and applicable corrective actions) in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 670BA–24–012, Revision B, dated July 25, 2007. Do all applicable related investigative and corrective actions before further flight. (2) Actions done before the effective date of this AD in accordance with Bombardier Service Bulletin 670BA–24–012, dated April 18, 2005, or Revision A, dated October 25, 2006, are acceptable for compliance with the corresponding requirements of this AD. 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. (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–2008–24, dated July 3, 2008, and Bombardier Service Bulletin 670BA–24– 012, Revision B, dated July 25, 2007, for related information. Issued in Renton, Washington, on October 10, 2008. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E8–25309 Filed 10–22–08; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2008–1120; Directorate Identifier 2008–CE–064–AD] RIN 2120–AA64 Airworthiness Directives; Air Tractor, Inc. Models AT–200, AT–300, AT–400, AT–500, AT–600, and AT–800 Series Airplanes overturn skid plate installed on Model AT–401B airplanes. We are proposing this AD to prevent the front and rear connections of the overturn skid plate to the airplane from breaking, which could allow foreign debris to enter the cockpit during an airplane overturn. This condition, if not corrected, could lead to pilot injury. DATES: We must receive comments on this proposed AD by November 24, 2008. Use one of the following addresses to comment on this proposed AD: • 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 proposed AD, contact Air Tractor, Inc., P.O. Box 485, Olney, Texas 76374; telephone: (940) 564–5616; fax: (940) 564–5612; e-mail: airmail@airtractor.com; Internet: https:// www.airtractor.com. FOR FURTHER INFORMATION CONTACT: Andy McAnaul, Aerospace Engineer, ASW–150, FAA San Antonio MIDO–43, 10100 Reunion Pl., Ste. 650, San Antonio, Texas 78216; telephone: (210) 308–3365; fax: (210) 308–3370. SUPPLEMENTARY INFORMATION: ADDRESSES: AGENCY: Comments Invited Note 1: This AD differs from the MCAI and/or service information as follows: No differences. Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Notice of proposed rulemaking (NPRM). Other FAA AD Provisions (g) The following provisions also apply to this AD: (1) Alternative Methods of Compliance (AMOCs): The Manager, Airframe and Propulsion Branch, ANE–171, 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 Aircraft Certification Office, 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 SUMMARY: We propose to supersede Airworthiness Directive (AD) 2008–11– 17, which applies to certain Air Tractor, Inc. Models AT–200, AT–300, AT–400, AT–500, AT–600, and AT–800 series airplanes. AD 2008–11–17 currently requires you to install an overturn skid plate kit or a modification to the overturn skid plate already installed. Since we issued AD 2008–11–17, the manufacturer has notified us that Model AT–401B airplanes also require a modification to the overturn skid plate. Consequently, this proposed AD would retain the actions of AD 2008–11–17 and add the requirement to modify the We invite you to send any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number, ‘‘FAA–2008–1120; Directorate Identifier 2008–CE–064–AD’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of 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 dwashington3 on PRODPC61 with PROPOSALS FAA AD Differences VerDate Aug<31>2005 14:57 Oct 22, 2008 Jkt 217001 PO 00000 Frm 00013 Fmt 4702 Sfmt 4702 E:\FR\FM\23OCP1.SGM 23OCP1

Agencies

[Federal Register Volume 73, Number 206 (Thursday, October 23, 2008)]
[Proposed Rules]
[Pages 63094-63096]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-25309]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1115; Directorate Identifier 2008-NM-134-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-SD24 aircraft fuel system against the new fuel 
tank safety standards. * * *
    The assessment showed that a single failure due to chafing of 
fuel system wiring with high power wiring at the centre fuel tank 
front spar could result in overheating of the fuel boost pump. The 
assessment also showed that chafing of the high power wiring with 
the centre fuel tank front spar structures could result in 
overheating of the fuel tank wall. Overheating of the fuel tank wall 
could lead to hot surface ignition resulting 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 November 24, 
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, 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-2008-1115; 
Directorate Identifier 2008-NM-134-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-
2008-24, 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 the 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 a single failure due to chafing of 
fuel system wiring with high power wiring at the centre fuel tank 
front spar could result in overheating of the fuel boost pump. The 
assessment also showed that chafing of the high power wiring with 
the centre fuel tank front spar structures could result in 
overheating of the fuel tank wall. Overheating of the fuel tank wall 
could lead to hot surface ignition resulting in a fuel tank 
explosion.
    To correct the unsafe condition, this directive mandates 
separation of the high power wiring from the fuel system wiring at 
the centre fuel tank front spar area and the installation of 
additional clamping and support for the high power wiring [i.e., 
modifying the routing and support of electrical wires in the centre 
fuel tank front spar area].

Required actions also include an inspection to determine if pins have a 
minimum of one thread above the nuts, and a visual inspection for 
damage of the sealant. Corrective actions include replacing pins and 
nuts and applying sealant. 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

[[Page 63095]]

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-24-012, Revision B, 
dated July 25, 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 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 102 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 $7,646 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 $2,513,154, or $15,806 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, 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. (Formerly Canadair): Docket No. FAA-2008-1115; 
Directorate Identifier 2008-NM-134-AD.

Comments Due Date

    (a) We must receive comments by November 24, 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 the new fuel 
tank safety standards, introduced in Chapter 525 of the 
Airworthiness Manual through Notice of Proposed Amendment (NPA) 
2002-043. The identified non-

[[Page 63096]]

compliances were assessed using Transport Canada Policy Letter No. 
525-001 to determine if mandatory corrective action was required.
    The assessment showed that a single failure due to chafing of 
fuel system wiring with high power wiring at the center fuel tank 
front spar could result in overheating of the fuel boost pump. The 
assessment also showed that chafing of the high power wiring with 
the centre fuel tank front spar structures could result in 
overheating of the fuel tank wall. Overheating of the fuel tank wall 
could lead to hot surface ignition resulting in a fuel tank 
explosion.
    To correct the unsafe condition, this directive mandates 
separation of the high power wiring from the fuel system wiring at 
the centre fuel tank front spar area and the installation of 
additional clamping and support for the high power wiring [i.e., 
modifying the routing and support of electrical wires in the center 
fuel tank front spar area].

Required actions also include an inspection to determine if pins 
have a minimum of one thread above the nuts, and a visual inspection 
for damage of the sealant. Corrective actions include replacing pins 
and nuts and applying sealant.

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 routing and support of the electrical wires in the 
center fuel tank front spar area (including an inspection to 
determine if pins have a minimum of one thread above the nuts, and a 
visual inspection for damage of the sealant, and applicable 
corrective actions) in accordance with the Accomplishment 
Instructions of Bombardier Service Bulletin 670BA-24-012, Revision 
B, dated July 25, 2007. Do all applicable related investigative and 
corrective actions before further flight.
    (2) Actions done before the effective date of this AD in 
accordance with Bombardier Service Bulletin 670BA-24-012, dated 
April 18, 2005, or Revision A, dated October 25, 2006, are 
acceptable for compliance with the corresponding requirements of 
this AD.

FAA AD Differences

    Note 1: 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, 
Airframe and Propulsion Branch, ANE-171, 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 
Aircraft Certification Office, 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-2008-24, 
dated July 3, 2008, and Bombardier Service Bulletin 670BA-24-012, 
Revision B, dated July 25, 2007, for related information.

    Issued in Renton, Washington, on October 10, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-25309 Filed 10-22-08; 8:45 am]
BILLING CODE 4910-13-P

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