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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. FAA-2008-0898; Directorate Identifier 2007-NM-200-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 certain Boeing Model 767-200 and 767-300 series airplanes. This proposed AD would require detailed inspections of the aft pressure bulkhead for damage, mid-frequency eddy current (MFEC) and low frequency eddy current (LFEC) inspections of radial web lap splices, tear strap splices, and super tear strap splices for cracking, and corrective actions if necessary. This AD results from analysis that indicates fatigue cracks of the web lap splice, tear strap splice, or super tear strap splice of the aft bulkhead are expected to occur on certain Boeing Model 767-200 and 767-300 series airplanes. We are proposing this AD to detect and correct fatigue cracks of the aft pressure bulkhead, which could result in rapid decompression of the passenger compartment and possible damage or interference with airplane control systems that penetrate the bulkhead, and consequent loss of controllability of the airplane. 

# DATES:

We must receive comments on this proposed AD by October 6, 2008. 

# 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 AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. 

## 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:

Tamara L. Anderson, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6421; 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-2008-0898; Directorate Identifier 2007-NM-200-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                           ( print page 49367)                        substantive verbal contact we receive about this proposed AD.                 

## Discussion 

                    We have previously issued AD 2005-03-11, amendment 39-13967 (70 FR 7174, February 11, 2005). (A correction of the rule was published in the                     **Federal Register**                     on March 11, 2005 (70 FR 12119, March 11, 2005).) That AD applies to certain Boeing Model 767-200 and 767-300 series airplanes, line numbers 1 through 175 inclusive. That AD was prompted by a report of multiple-site fatigue cracking (multiple-site damage) in two lap splices on the aft pressure bulkhead of one airplane. That AD currently requires repetitive detailed and eddy current inspections of the aft pressure bulkhead for damage and cracking, one-time detailed and high frequency eddy current inspections of any “oil can” located on the aft pressure bulkhead for damage and cracking, and related corrective actions if necessary.                 

Since the issuance of that AD, analysis indicates that fatigue cracks of the web lap splice, tear strap splice, or super tear strap splice of the aft bulkhead are expected to occur on Boeing Model 767-200 and 767-300 series airplanes having line numbers 176 through 423 inclusive that have accumulated 35,000 or more total flight cycles. There have been no reports of such fatigue cracks on these in-service airplanes. Such fatigue cracking, if not corrected, could result in rapid decompression of the passenger compartment and possible damage or interference with airplane control systems that penetrate the bulkhead, and consequent loss of controllability of the airplane. 

## Relevant Service Information 

We have reviewed Boeing Alert Service Bulletin 767-53A0147, dated August 16, 2007. The service bulletin describes procedures for: 
    - Doing an initial detailed inspection of the aft pressure bulkhead for damage such as dents, punctures, nicks, gouges, cracks, corrosion, and scratches, and repeating those inspections.
    - Doing initial mid-frequency eddy current (MFEC) and low-frequency eddy current (LFEC) inspections of the radial web lap splices, tear strap splices, and super tear strap splices for cracking, and repeating those inspections.
    - Contacting Boeing for inspection instructions where inspection is prevented by a repair common to the inspection area.
    - Doing applicable corrective actions, which include repairing any damage that exceeds certain allowable limits, and contacting Boeing for repair instructions. The service bulletin specifies the following compliance times:
    - For the initial inspections: 35,000 total flight-cycles, or 18 months or 3,000 flight-cycles after the date of the service bulletin, whichever occurs first.
    - For the repetitive inspections: Within 3,000 flight-cycles of the initial inspection, and thereafter at intervals not to exceed 3,000 flight-cycles.
    - For the applicable corrective actions: Before further flight.

## 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 accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between Proposed Rule and Service Bulletin.” 

## Differences Between Proposed Rule and Service Bulletin 

The service bulletin specifies to contact the manufacturer for instructions on how to repair and inspect certain conditions, but this proposed AD would require repairing and inspecting 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 an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make those findings.

## Clarification of Repetitive Inspections Specified in Service Bulletin 

The Accomplishment Instructions of the service bulletin specifies to only repeat the inspections if no crack is found. However, Table 2 of paragraph 1.E, “Compliance,” of the service bulletin identifies repeat intervals for the inspections, regardless of inspection findings. The intent is that the inspections be repeated for all findings. Therefore, this proposed AD would require repetitive inspections at the applicable repeat intervals listed in Table 2 of paragraph 1.E., “Compliance.” 

## Costs of Compliance 

There are about 244 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 84 airplanes of U.S. registry. The proposed actions would take about 31 work hours 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 $208,320, or $2,480 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

      ( print page 49368)    

## 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): 

**Boeing:**                                 Docket No. FAA-2008-0898; Directorate Identifier 2007-NM-200-AD.                             

## Comments Due Date 

(a) The FAA must receive comments on this AD action by October 6, 2008. 

## Affected ADs 

(b) None. 

## Applicability 

(c) This AD applies to Boeing Model 767-200 and 767-300 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 767-53A0147, dated August 16, 2007. 

## Unsafe Condition 

(d) This AD results from analysis that indicates fatigue cracks of the web lap splice, tear strap splice, or super tear strap splice of the aft bulkhead are expected to occur on certain Boeing Model 767-200 and 767-300 series airplanes. We are proposing this AD to detect and correct fatigue cracks of the aft pressure bulkhead, which could result in rapid decompression of the passenger compartment and possible damage or interference with airplane control systems that penetrate the bulkhead, and consequent loss of controllability of the airplane. 

## Compliance 

(e) Comply with this AD within the compliance times specified, unless already done. 

## Inspections and Applicable Related Investigative and Corrective Actions 

(f) Except as provided by paragraphs (f)(1) and (f)(2) of this AD: At the applicable compliance time and repeat intervals listed in Tables 1 and 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 767-53A0147, dated August 16, 2007, do detailed inspections of the aft pressure bulkhead for damage, mid-frequency eddy current (MFEC) and low-frequency eddy current (LFEC) inspections of radial web lap splices, tear strap splices, and super tear strap splices for cracking and applicable corrective actions by accomplishing all the applicable actions specified in the Accomplishment Instructions of the service bulletin. 

(1) Where Table 1 of paragraph 1.E., “Compliance,” of the service bulletin specifies a compliance time after the date on the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD. 

(2) Where the service bulletin specifies a compliance time of “As given by Boeing” or to contact Boeing for the appropriate action, this AD requires, before further flight, inspections of the area of repair and repair of any damaged/cracked part, as applicable, using a method approved in accordance with the procedures specified in paragraph (g) of this AD. 

## Alternative Methods of Compliance (AMOCs) 

(g)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, ATTN: Tamara L. Anderson, Aerospace Engineer, Airframe Branch, ANM-120S, 1601 Lind Avenue, SW., Renton, Washington, telephone (425) 917-6421; fax (425) 917-6590; has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. 

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. 

(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 an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who 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 August 8, 2008. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. E8-19363 Filed 8-20-08; 8:45 am] 

BILLING CODE 4910-13-P