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Proposed Rule

Airworthiness Directives; Short Brothers PLC Model SD3 Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

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 that would supersede an existing AD. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

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

* * * * *

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

* * * * *

The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.

DATES:

We must receive comments on this proposed AD by April 29, 2010.

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 Short Brothers PLC, Airworthiness, P.O. Box 241, Airport Road, Belfast, BT3 9DZ Northern Ireland; telephone +44(0)2890-462469; fax +44(0)2890-468444; e-mail michael.mulholland@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 or 425-227-1152.

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.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Todd Thompson, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone (425) 227-1175; fax (425) 227-1149.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:Start Printed Page 12155

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-2010-0225; Directorate Identifier 2009-NM-203-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 have lengthened the 30-day comment period for proposed ADs that address MCAI originated by aviation authorities of other countries to provide adequate time for interested parties to submit comments. The comment period for these proposed ADs is now typically 45 days, which is consistent with the comment period for domestic transport ADs.

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

On June 5, 2006, we issued AD 2006-12-18, Amendment 39-14644 (71 FR 34801, June 16, 2006). That AD required actions intended to address an unsafe condition on the products listed above.

Since we issued AD 2006-12-18, we have determined that additional limitations for fuel tank systems and Critical Design Control Configuration Limitations (CDCCLs) are necessary. The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Airworthiness Directive 2006-0198, dated July 11, 2006 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

Subsequent to accidents involving Fuel Tank System explosions in flight * * * and on ground, the FAA published Special Federal Aviation Regulation 88 (SFAR88) in June 2001. SFAR 88 required a safety review of the aircraft Fuel Tank System to determine that the design meets the requirements of FAR [Federal Aviation Regulation] § 25.901 and § 25.981(a) and (b).

A similar regulation has been recommended by the JAA [Joint Aviation Authorities] to the European National Aviation Authorities in JAA letter 04/00/02/07/03-L024 of 3 February 2003. The review was requested to be mandated by NAA's [National Airworthiness Authorities] using JAR [Joint Aviation Requirement] § 25.901(c), § 25.1309.

In August 2005 EASA published a policy statement on the process for developing instructions for maintenance and inspection of Fuel Tank System ignition source prevention (EASA D 2005/CPRO, www.easa.eu.int/​home/​cert_​policy_​statements_​en.html) that also included the EASA expectations with regard to compliance times of the corrective actions on the unsafe and the not unsafe part of the harmonised design review results. On a global scale the TC [type certificate] holders committed themselves to the EASA published compliance dates (see EASA policy statement). The EASA policy statement has been revised in March 2006: the date of 31-12-2005 for the unsafe related actions has now been set at 01-07-2006.

Fuel Airworthiness Limitations are items arising from a systems safety analysis that have been shown to have failure mode(s) associated with an `unsafe condition' as defined in FAA's memo 2003-112-15 `SFAR 88—Mandatory Action Decision Criteria'. These are identified in Failure Conditions for which an unacceptable probability of ignition risk could exist if specific tasks and/or practices are not performed in accordance with the manufacturers' requirements.

This EASA Airworthiness Directive mandates the Fuel System Airworthiness Limitations, comprising maintenance/inspection tasks and Critical Design Control Configuration Limitations (CDCCL) for the type of aircraft, that resulted from the design reviews and the JAA recommendation and EASA policy statement mentioned above.

Revision History: PAD [proposed airworthiness directive] 06-018R1 has been issued to endorse comments received for PAD 06-018 and due to the change of the EASA policy statement on fuel tank safety on March 2006.

You may obtain further information by examining the MCAI in the AD docket.

The FAA has examined the underlying safety issues involved in fuel tank explosions on several large transport airplanes, including the adequacy of existing regulations, the service history of airplanes subject to those regulations, and existing maintenance practices for fuel tank systems. As a result of those findings, we issued a regulation titled “Transport Airplane Fuel Tank System Design Review, Flammability Reduction and Maintenance and Inspection Requirements” (66 FR 23086, May 7, 2001). In addition to new airworthiness standards for transport airplanes and new maintenance requirements, this rule included Special Federal Aviation Regulation No. 88 (“SFAR 88,” Amendment 21-78, and subsequent Amendments 21-82 and 21-83).

Among other actions, SFAR 88 requires certain type design (i.e., type certificate (TC) and supplemental type certificate (STC)) holders to substantiate that their fuel tank systems can prevent ignition sources in the fuel tanks. This requirement applies to type design holders for large turbine-powered transport airplanes and for subsequent modifications to those airplanes. It requires them to perform design reviews and to develop design changes and maintenance procedures if their designs do not meet the new fuel tank safety standards. As explained in the preamble to the rule, we intended to adopt airworthiness directives to mandate any changes found necessary to address unsafe conditions identified as a result of these reviews.

In evaluating these design reviews, we have established four criteria intended to define the unsafe conditions associated with fuel tank systems that require corrective actions. The percentage of operating time during which fuel tanks are exposed to flammable conditions is one of these criteria. The other three criteria address the failure types under evaluation: single failures, single failures in combination with a latent condition(s), and in-service failure experience. For all four criteria, the evaluations included consideration of previous actions taken that may mitigate the need for further action.

The Joint Aviation Authorities (JAA) issued a regulation that is similar to SFAR 88. Under that regulation, the JAA stated that all members of the European Civil Aviation Conference (ECAC) that hold type certificates for transport category airplanes are required to conduct a design review against explosion risks.

We have determined that the actions identified in this AD are necessary to reduce the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.

Relevant Service Information

Bombardier has issued the temporary revisions (TRs) listed in the following table.Start Printed Page 12156

AMM Temporary Revisions

Model—Bombardier temporary revision—Dated—To the AMM—
SD3-60 airplanesTR360-AMM-55November 11, 2005Bombardier SD3-60 AMM, 360/MM SD3-60.
SD3-60 airplanesTR360-AMM-56November 11, 2005Bombardier SD3-60 AMM, 360/MM SD3-60.

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 54 products of U.S. registry.

The actions that are required by AD 2006-12-18 and retained in this proposed AD take about 41 work-hours per product, at an average labor rate of $85 per work hour. Required parts cost about $10 per product. Based on these figures, the estimated cost of the currently required actions is $3,495 per product.

We estimate that it would take about 1 work-hour per product to comply with the new basic requirements of this proposed AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $4,590, or $85 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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. The FAA amends § 39.13 by removing Amendment 39-14644 (71 FR 34801, June 16, 2006) and adding the following new AD:

Short Brothers PLC: Docket No. FAA-2010-0225; Directorate Identifier 2009-NM-203-AD.

Comments Due Date

(a) We must receive comments by April 29, 2010.

Affected ADs

(b) This AD supersedes AD 2006-12-18, Amendment 39-14644.

Applicability

(c) This AD applies to all Short Brothers PLC Model SD3-60 SHERPA, SD3-SHERPA, SD3-30, and SD3-60 airplanes, certificated in any category.

Note 1:

This AD requires revisions to certain operator maintenance documents to include new inspections. Compliance with these inspections is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these inspections, the operator may not be able to accomplish the inspections described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance according to paragraph (l) of this AD. The request should include a description of changes to the required inspections that will ensure the continued damage tolerance of the affected structure. The FAA has provided guidance for this determination in Advisory Circular (AC) 25-1529.

Start Printed Page 12157

Subject

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

Reason

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

Subsequent to accidents involving Fuel Tank System explosions in flight * * * and on ground, the FAA published Special Federal Aviation Regulation 88 (SFAR88) in June 2001. SFAR 88 required a safety review of the aircraft Fuel Tank System to determine that the design meets the requirements of FAR [Federal Aviation Regulation] § 25.901 and § 25.981(a) and (b).

A similar regulation has been recommended by the JAA [Joint Aviation Authorities] to the European National Aviation Authorities in JAA letter 04/00/02/07/03-L024 of 3 February 2003. The review was requested to be mandated by NAA's [National Airworthiness Authorities] using JAR [Joint Aviation Requirement] § 25.901(c), § 25.1309.

In August 2005 EASA [European Aviation Safety Agency] published a policy statement on the process for developing instructions for maintenance and inspection of Fuel Tank System ignition source prevention (EASA D 2005/CPRO, www.easa.eu.int/​home/​cert_​policy_​statements_​en.html) that also included the EASA expectations with regard to compliance times of the corrective actions on the unsafe and the not unsafe part of the harmonised design review results. On a global scale the TC [type certificate] holders committed themselves to the EASA published compliance dates (see EASA policy statement). The EASA policy statement has been revised in March 2006: the date of 31-12-2005 for the unsafe related actions has now been set at 01-07-2006.

Fuel Airworthiness Limitations are items arising from a systems safety analysis that have been shown to have failure mode(s) associated with an ‘unsafe condition’ as defined in FAA's memo 2003-112-15 ‘SFAR 88—Mandatory Action Decision Criteria’. These are identified in Failure Conditions for which an unacceptable probability of ignition risk could exist if specific tasks and/or practices are not performed in accordance with the manufacturers' requirements.

This EASA Airworthiness Directive mandates the Fuel System Airworthiness Limitations, comprising maintenance/inspection tasks and Critical Design Control Configuration Limitations (CDCCL) for the type of aircraft, that resulted from the design reviews and the JAA recommendation and EASA policy statement mentioned above.

Revision History: PAD [proposed airworthiness directive] 06-018R1 has been issued to endorse comments received for PAD 06-018 and due to the change of the EASA policy statement on fuel tank safety on March 2006.

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.

Restatement of Requirements of AD 2006-12-18, With Revised Service Information

Revision of Airplane Flight Manual (AFM) With Additional AFM References in Table 1 of This AD

(g) Within 30 days after July 21, 2006 (the effective date of AD 2006-12-18), revise the Limitations and Normal Procedures sections of the AFMs as specified in Table 1 of this AD to include the information in the applicable Shorts advance amendment bulletins as specified in Table 1 of this AD. The advance amendment bulletins address operation during icing conditions and fuel system failures. Thereafter, operate the airplane according to the limitations and procedures in the applicable advance amendment bulletin.

Note 2:

The requirements of paragraph (g) of this AD may be done by inserting a copy of the applicable advance amendment bulletin into the AFM. When the applicable advance amendment bulletin has been included in general revisions of the AFM, the general revisions may be inserted into the AFM and the advance amendment bulletin may be removed, provided the relevant information in the general revision is identical to that in the advance amendment bulletin.

Table 1—AFM Revisions

Airplane model—Shorts advance amendment bulletin—AFM—
SD3-30 airplanes1/2004, dated July 13, 2004SBH.3.2, SBH.3.3, SBH.3.6, SBH.3.7, SBH.3.8, and SB.3.9.
SD3-60 airplanes1/2004, dated July 13, 2004SB.4.3, SB.4.6, and SB.4.8.
SD3-60 SHERPA airplanes1/2004, dated July 13, 2004SB.5.2 or 6.2.
SD3-SHERPA airplanes1/2004, dated July 13, 2004SB.6.2 or 5.2.

Revision of Airworthiness Limitation (AWL) Section

(h) Within 180 days after July 21, 2006: Revise the AWL section of the Instructions for Continued Airworthiness by incorporating airplane maintenance manual (AMM) Sections 5-20-01 and 5-20-02 as introduced by the Shorts temporary revisions (TR) specified in Table 2 of this AD into the AWL section of the AMMs for the airplane models specified in Table 2 of this AD, except as required by paragraph (j) of this AD. Thereafter, except as provided by paragraph (l)(1) of this AD, no alternative structural inspection intervals may be approved for the longitudinal skin joints in the fuselage pressure shell.

Note 3:

The requirements of paragraph (h) of this AD may be done by inserting a copy of the applicable TR into the applicable AMM. When the TR has been included in general revisions of the AMM, the general revisions may be inserted in the AMM and the TR may be removed, provided the relevant information in the general revision is identical to that in the TR.

Table 2—AMM Temporary Revisions

Airplane model—Temporary revision—Dated—AMM—
SD3-30 airplanesTR330-AMM-13June 21, 2004SD3-30 AMM.
SD3-30 airplanesTR330-AMM-14June 21, 2004SD3-30 AMM.
SD3-60 airplanesTR360-AMM-33July 27, 2004SD3-60 AMM.
SD3-60 airplanesTR360-AMM-34July 27, 2004SD3-60 AMM.
SD3-60 SHERPA airplanesTRSD360S-AMM-14July 29, 2004SD3-60 SHERPA AMM.
SD3-60 SHERPA airplanesTRSD360S-AMM-15July 29, 2004SD3-60 SHERPA AMM.
SD3-SHERPA airplanesTRSD3S-AMM-15July 28, 2004SD3 SHERPA AMM.
SD3-SHERPA airplanesTRSD3S-AMM-16July 28, 2004SD3 SHERPA AMM.
Start Printed Page 12158

Resistance Check, Inspection, and Jumper Installation

(i) Within 180 days after July 21, 2006: Perform the insulation resistance check, general visual inspections, and bonding jumper wire installations; in accordance with Shorts Service Bulletin SD330-28-37, SD360-28-23, SD360 SHERPA-28-3, or SD3 SHERPA-28-2; all dated June 2004; as applicable. If any defect or damage is discovered during any inspection or check required by this AD, before further flight, repair the defect or damage using a method approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; the Civil Aviation Authority (CAA) (or its delegated agent); or EASA (or its delegated agent).

Note 4:

For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

New Requirements of This AD

Actions and Compliance

Revision of AWL Section: New Limitations and CDCCLs

(j) Within 90 days after the effective date of this AD: Revise the AWL section of the Instructions for Continued Airworthiness by incorporating aircraft maintenance manual (AMM) Sections 5-20-01 and 5-20-02 as introduced by the Bombardier temporary revisions (TRs) specified in Table 3 of this AD into the AWL section of the AMMs for the airplane models specified in Table 3 of this AD. Doing this revision terminates the requirement to incorporate Shorts TRs TR360-AMM-33, dated July 27, 2004; and TR360-AMM-34, dated July 27, 2004; specified in paragraph (h) of this AD. After doing this revision, TR360-AMM-33, dated July 27, 2004; and TR360-AMM-34, dated July 27, 2004; required by paragraph (h) of this AD may be removed.

Table 3—AMM Temporary Revisions

Model—Bombardier temporary revision—Dated—To this AMM—
SD3-60 airplanesTR360-AMM-55November 11, 2005Bombardier SD3-60 AMM, 360/MM.
SD3-60 airplanesTR360-AMM-56November 11, 2005Bombardier SD3-60 AMM, 360/MM.

Note 5:

The requirements of paragraph (j) of this AD may be done by inserting a copy of the applicable TR into the applicable AMM. When the TR has been included in general revisions of the AMM, the general revisions may be inserted in the AMM and the TR may be removed, provided the relevant information in the general revision is identical to that in the TR.

(k) After accomplishing the actions specified in paragraph (j) of this AD, no alternative inspections, inspection intervals, or CDCCLs may be used unless the inspections, intervals, or CDCCLs are approved as an alternative method of compliance (AMOC), in accordance with the procedures specified in paragraph (l) of this AD.

Explanation of CDCCL Requirements

Note 6:

Notwithstanding any other maintenance or operational requirements, components that have been identified as airworthy or installed on the affected airplanes before the revision of the AMM, as required by paragraph (h) or (j) of this AD, do not need to be reworked in accordance with the CDCCLs. However, once the AMM has been revised, future maintenance actions on these components must be done in accordance with the CDCCLs.

FAA AD Differences

Note 7:

This AD differs from the MCAI and/or service information as follows: No differences.

Other FAA AD Provisions

(l) The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Todd Thompson, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-1175; fax (425) 227-1149. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards 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.

(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120-0056.

Related Information

(m) Refer to MCAI EASA Airworthiness Directive 2006-0198, dated July 11, 2006; Shorts Service Bulletins SD330-28-37, SD360-28-23, SD360 SHERPA-28-3, and SD3 SHERPA-28-2, all dated June 2004; and the service information listed in Tables 1, 2, and 3 of this AD; for related information.

Start Signature

Issued in Renton, Washington, on March 4, 2010.

Suzanne Masterson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 2010-5516 Filed 3-12-10; 8:45 am]

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