Document Headings

                    Document headings vary by document type but may contain                    the following:                  
                -                       the agency or agencies that issued and signed a document                    
                -                       the number of the CFR title and the number of each part                      the document amends, proposes to amend, or is directly                      related to                    
                -                       the agency docket number / agency internal file number                    
                -                       the RIN which identifies each regulatory action listed in                      the Unified Agenda of Federal Regulatory and Deregulatory                      Actions                    

                    See the                                          Document Drafting Handbook                                        for more details.                  

###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. FAA-2010-0547; Directorate Identifier 2009-NM-234-AD] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration (FAA), DOT. 

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

We propose to adopt a new airworthiness directive (AD) for all Model 757 airplanes. This proposed AD would require a detailed inspection of the inboard and outboard main track downstop assemblies and a torque application to the main track downstop assembly nuts of slat numbers 1 through 10, excluding the outboard track of slats 1 and 10, a detailed inspection of all slat track housings, and related corrective actions if necessary. This proposed AD results from reports of fuel leaking from the front spar of the wing through the slat track housing. We are proposing this AD to detect and correct incorrectly installed main track downstop assemblies, which, when the slat is retracted, could cause a puncture in the slat track housing leading to a fuel leak and potential fire. 

# DATES:

We must receive comments on this proposed AD by July 19, 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 W12-140, 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 Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; e-mail                         *me.boecom@boeing.com;*                         Internet                         *https://www.myboeingfleet.com.*                         You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.                     

## Examining the AD Docket 

                    You may examine the AD docket on the Internet at                     *http://www.regulations.gov;*                     or in person at the Docket 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:

Chris Hartman, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone (425) 917-6432; fax (425) 917-6590. 

# 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-2010-0547; Directorate Identifier 2009-NM-234-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 because of those comments.                 

                    We will post all comments we receive, without change, to                     *http://www.regulations.gov,*                     including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.                 

## Discussion 

We have received two reports of fuel leaking from the front spar of the wing through the slat track housing. In at least one case, the source of the fuel leak was from a puncture of the slat track housing caused by a roller that had fallen into the slat track housing. The roller, which was not a component of the slat installation or the slat track support rib, subsequently punctured the slat track housing when the slat was retracted. While fuel leaking from a punctured slat track housing could lead to a fire, in both cases, no fires were reported. 

## Relevant Service Information 

We have reviewed Boeing Special Attention Bulletin 757-57-0068, dated September 15, 2009. That service bulletin describes procedures for doing a detailed inspection of the inboard and outboard main track downstop assemblies and for applying torque to the main track downstop assembly nuts of slat numbers 1 through 10, excluding the outboard track of slats 1 and 10. That service bulletin also describes procedures for doing a detailed inspection of both inboard and outboard slat track housings of slat numbers 1 through 10 for foreign object debris or visible damage, and doing corrective actions if necessary. Boeing Special Attention Bulletin 757-57-0068, dated September 15, 2009, specifies the following corrective actions: 
    - Removing and reinstalling incorrectly installed main track downstop assemblies.
    - Replacing damaged or missing main track downstop assembly parts.
    - Removing foreign object debris.
    - Repairing or replacing damaged slat track housings.
    - Contacting Boeing for repair instructions.

Boeing Special Attention Bulletin 757-57-0068, dated September 15, 2009, specifies that the detailed inspections of the main track downstop assembles and the slat track housings be done before 24 months after the date on that service bulletin. That service bulletin also specifies that application of torque to the main track downstop assembly nuts be done before 24 months after the date on that service bulletin. That service bulletin also specifies that corrective actions be done before further flight. 

## FAA's Determination and Requirements of This Proposed AD 

                    We are proposing this AD because we evaluated all relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. This proposed AD would require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between                           ( print page 31328)                        the Proposed AD and the Service Bulletin.” The proposed AD would also require sending the inspection results to Boeing.                 

## Differences Between the Proposed AD and the Service Bulletin 

Boeing Special Attention Bulletin 757-57-0068, dated September 15, 2009, specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions in one of the following ways: 
    - Using a method that we approve; or
    - Using data that meet the certification basis of the airplane, and that have been approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that we have authorized to make those findings.

## Costs of Compliance 

We estimate that this proposed AD would affect 645 airplanes of U.S. registry. We also estimate that it would take about 19 work-hours per product to comply with this proposed AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $1,041,675, or $1,615 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. 

You can find our regulatory evaluation and the estimated costs of compliance 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 

2. The FAA amends § 39.13 by adding the following new AD:

**The Boeing Company:**                                 Docket No. FAA-2010-0547; Directorate Identifier 2009-NM-234-AD.                             

## Comments Due Date 

(a) We must receive comments by July 19, 2010. 

## Affected ADs 

(b) None. 

## Applicability 

(c) This AD applies to all The Boeing Company Model 757-200, -200PF, -200CB, and -300 series airplanes, certificated in any category. 

## Subject 

(d) Air Transport Association (ATA) of America Code 57: Wings. 

## Unsafe Condition 

(e) This AD results from reports of fuel leaking from the front spar of the wing through the slat track housing. The Federal Aviation Administration is issuing this AD to detect and correct incorrectly installed main track downstop assemblies, which, when the slat is retracted, could cause a puncture in the slat track housing leading to a fuel leak and potential fire. 

## 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. 

## Inspection and Torque Application 

(g) Except as required by paragraph (h) of this AD, at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-57-0068, dated September 15, 2009: Perform a detailed inspection of the inboard and outboard main track downstop assemblies of slat numbers 1 through 10, excluding the outboard main track downstop assemblies of slat numbers 1 and 10 and perform a detailed inspection of all slat track housings for foreign object debris, visible damage, and missing parts, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-57-0068, dated September 15, 2009. At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-57-0068, dated September 15, 2009, apply torque to the main track down stop assembly nuts to make sure they have been correctly installed, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-57-0068, dated September 15, 2009. Do all applicable corrective actions before further flight, in accordance with Boeing Special Attention Service Bulletin 757-57-0068, dated September 15, 2009. 

## Exceptions to the Service Bulletin 

(h) Where Boeing Special Attention Service Bulletin 757-57-0068, dated September 15, 2009, specifies a compliance time “after the date on this service bulletin,” this AD requires compliance at the specified time after the effective date of this AD. 

(i) Where Boeing Special Attention Service Bulletin 757-57-0068, dated September 15, 2009, specifies to contact Boeing for appropriate action: Before further flight, repair the damage using a method approved in accordance with the procedures specified in paragraph (j) of this AD. 

## Alternative Methods of Compliance (AMOCs) 

                                (j)(1) The Manager, Seattle Aircraft Certification Office, 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: Chris Hartman, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone (425) 917-6432; fax (425) 917-6590. Information may be e-mailed to:                                 *9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.*

                                (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 principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District                                       ( print page 31329)                                    Office. The AMOC approval letter must specifically reference this AD.                             

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD. 

Issued in Renton, Washington, on May 24, 2010. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, Aircraft Certification Service. 

[FR Doc. 2010-13306 Filed 6-2-10; 8:45 am] 

BILLING CODE 4910-13-P