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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. FAA-2006-25850; Directorate Identifier 2006-NM-128-AD] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT). 

# ACTION:

Notice of proposed rulemaking (NPRM). 

# SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all McDonnell Douglas Model MD-11 and -11F airplanes. This proposed AD would require revising the maintenance inspection program that provides for inspection of principal structural elements (PSEs) and replacement of safe-life parts, to incorporate a new revision to the MD-11 Airworthiness Limitations Instructions. The revision would reduce inspection intervals for fatigue cracking of certain PSEs, and expand the inspection area for a certain other PSE. This proposed AD results from a revised damage tolerance analysis. We are proposing this AD to detect and correct fatigue cracking of certain PSEs, which could adversely affect the structural integrity of the airplane. 

# DATES:

We must receive comments on this proposed AD by November 6, 2006. 

# ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD. 
      -  DOT Docket Web site:                          Go to                          http://dms.dot.gov                          and follow the instructions for sending your comments electronically.                       
      -  Government-wide rulemaking Web site:                          Go to                          http://www.regulations.gov                          and follow the instructions for sending your comments electronically.                       
      -  Mail:                          Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590.                     
      -  Fax : (202) 493-2251.                       
      -  Hand Delivery:                          Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.                     

Contact Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024), for the service information identified in this proposed AD. 

# FOR FURTHER INFORMATION CONTACT:

Maureen Moreland, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5238; fax (562) 627-5210. 

# SUPPLEMENTARY INFORMATION:

## Comments Invited 

                    We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your                           ( print page 54942)                        comments to an address listed in the                     **ADDRESSES**                     section. Include the docket number “FAA-2006-25850; Directorate Identifier 2006-NM-128-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                     *http://dms.dot.gov,*                     including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD.                 

                    Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act Statement in the                     **Federal Register**                     published on April 11, 2000 (65 FR 19477-78), or you may visit                     *http://dms.dot.gov.*

## Examining the Docket 

                    You may examine the AD docket on the Internet at                     *http://dms.dot.gov,*                     or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the                     **ADDRESSES**                     section. Comments will be available in the AD docket shortly after the Docket Management System receives them.                 

## Discussion 

Boeing has completed a revised damage tolerance analysis of certain principal structural elements (PSEs) on Model MD-11 and MD-11F airplanes. Boeing repeated the analysis to address additional crack growth scenarios as a result of in-service cracking and to correct the crack growth analysis spectrum which it found to underpredict operational loading. These new data indicate that the initial and repeat inspection intervals to detect fatigue cracking for certain PSEs must be revised. 

The actions specified by the proposed AD are intended to detect fatigue cracking of several wing PSEs and a tail pylon PSE. This fatigue cracking, if not detected and corrected, could adversely affect the structural integrity of the airplane. 

## Relevant Service Information 

We have reviewed Boeing MD-11 Airworthiness Limitations Instructions (ALI), Report Number MDC-K5225, Revision 11, dated March 2006. Among other things, Revision 11 of the ALI reduces certain initial and repeat intervals for inspections for fatigue cracking of certain PSEs, and expands the inspection area for a certain other PSE. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition. 

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

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. For this reason, we are proposing this AD, which would require operators to incorporate the Boeing MD-11 ALI, Report Number MDC-K5225, Revision 11, dated March 2006, into the applicable maintenance and inspection program. 

## Costs of Compliance 

There are about 102 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 93 airplanes of U.S. registry. The proposed maintenance and inspection program revision would take about 1 work hour per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $7,440, or $80 per airplane, per inspection cycle. 

## 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 have 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 that the 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. See the                     **ADDRESSES**                     section for a location to examine the regulatory evaluation.                 

# 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

2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD): 

**McDonnell Douglas:**                                 Docket No. FAA-2006-25850; Directorate Identifier 2006-NM-128-AD.                             

## Comments Due Date 

(a) The FAA must receive comments on this AD action by November 6, 2006. 

## Affected ADs 

(b) None. 

## Applicability 

(c) This AD applies to all McDonnell Douglas Model MD-11 and -11F airplanes, certificated in any category. 

# Note 1:

                                    This AD requires revisions to certain operator maintenance documents to incorporate new inspections for fatigue                                           ( print page 54943)                                        cracking of principal structural elements (PSEs). 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 incorporate 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 (h) 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.                                

## Unsafe Condition 

(d) This AD results from a revised damage tolerance analysis. We are issuing this AD to detect and correct fatigue cracking of certain principal structural elements (PSEs), which could adversely affect the structural integrity of the airplane. 

## Compliance 

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

## Revision of Airworthiness Limitations Section 

(f) Within 18 months after the effective date of this AD: Revise the Airworthiness Limitations section of the Instructions for Continued Airworthiness, Airworthiness Limitations Instructions (ALI), according to a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA. Boeing MD-11 ALI, Report Number MDC-K5225, Revision 11, dated March 2006, is one approved method. 

(g) Except as provided by paragraph (h) of this AD: After the actions specified in paragraph (f) of this AD have been done, no alternative inspection intervals or replacement times may be approved for the PSEs and safe-life limited parts specified in Boeing Report Number MDC-K5225, Revision 11, dated March 2006. 

## Alternative Methods of Compliance (AMOCs) 

(h)(1) The Manager, Los Angeles ACO, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. 

(2) An AMOC that provides an acceptable level of safety may be used for any repair required by accomplishing the actions in this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Los Angeles 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. 

(3) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

Issued in Renton, Washington, on September 12, 2006. 

Kevin M. Mullin, 

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

 [FR Doc. 06-7945 Filed 9-19-06; 8:45 am] 

BILLING CODE 4910-13-P