E6-1679. Airworthiness Directives; Boeing Model 747-200B, 747-200C, 747-200F, 747-300, 747-400, and 747SP Series Airplanes

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 747-200B, 747-200C, 747-200F, 747-300, 747-400, and 747SP series airplanes. This proposed AD would require doing a detailed inspection of the left and right longeron extension fittings, and corrective action if necessary. This proposed AD results from cracking found in the longeron extension fitting at body station 1480 due to accidental damage during production. We are proposing this AD to detect and correct cracking in the longeron extension fitting, which could result in rapid decompression of the airplane and possible in-flight breakup of the airplane fuselage.

DATES:

We must receive comments on this proposed AD by March 27, 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: [phone].
• 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 Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for the service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Nicholas Kusz, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2006-23819; Directorate Identifier 2005-NM-223-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 [phone]) 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

We have received a report indicating that a crack was found in the longeron extension fitting at body station 1480, on a Boeing Model 747-400 series airplane. (The airplane had accumulated 12,676 total flight cycles.) Investigation revealed that the crack occurred where a drill start had been made accidentally during airplane production. Cracking in the longeron extension fitting could extend and lead to reduced structural integrity of the bulkhead structure at body station 1480. This condition, if not corrected, could result in rapid decompression of the airplane and possible in-flight breakup of the airplane fuselage.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 747-53A2515, dated October 20, 2005. The service bulletin describes procedures for doing a detailed inspection of the left and right longeron extension fittings for damage and corrective action if necessary. The corrective action includes the following:

• Repairing any damage found to a longeron extension fitting, which includes removing any visibly damaged material, doing a high frequency eddy current inspection of the cut edge of the gusset for cracks and removing any damage if necessary, and making an insurance cut to remove any possible crack tip.
• If damage cannot be repaired in accordance with the service bulletin, replacing the damaged longeron extension fitting with a new longeron extension fitting.

The service bulletin refers to Boeing Alert Service Bulletin 747-53A2390, dated July 31, 1997, or Revision 1, dated July 6, 2000, as an additional source of service information for replacing a damaged longeron fitting with a new longeron extension fitting.

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. The proposed AD would also require sending the inspection results to the Manager, Seattle Aircraft Certification Office, FAA, if applicable.

Interim Action

This is considered to be interim action. The inspection reports that would be required by this proposed AD will enable the FAA to obtain better insight into the nature, cause, and extent of the cracking. Once we have received the inspection reports, we may consider further rulemaking to include additional airplanes.

Costs of Compliance

There are about 126 airplanes of the affected design in the worldwide fleet. This AD affects about 25 airplanes of U.S. registry The proposed inspection would take about 1 work hour per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $1,625, or $65 per airplane.

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

[Amended]

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

Boeing: Docket No. FAA-2006-23819; Directorate Identifier 2005-NM-223-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by March 27, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 747-200B, 747-200C, 747-200F, 747-300, 747-400, and 747SP series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 747-53A2515, dated October 20, 2005.

Unsafe Condition

(d) This AD results from cracking found in the longeron extension fitting at body station 1480 due to accidental damage during production. We are issuing this AD to detect and correct cracking in the longeron extension fitting, which could result in rapid decompression of the airplane and possible in-flight breakup of the airplane fuselage.

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.

Detailed Inspection

(f) At the applicable compliance time specified in paragraph (f)(1) or (f)(2) of this AD, do a detailed inspection of the left and right longeron extension fittings for damage, and before further flight do the corrective action if applicable, by accomplishing all the applicable actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2515, dated October 20, 2005.

Note 1:

Boeing Alert Service Bulletin 747-53A2515, dated October 20, 2005, refers to Boeing Alert Service Bulletin 747-53A2390, dated July 31, 1997, or Revision 1, dated July 6, 2000, as an additional source of service information for replacing a damaged longeron fitting with a new longeron extension fitting.

(1) For airplanes that have accomplished the inspection of the splice area for cracking as specified in Boeing Alert Service Bulletin 747-53A2390, dated July 31, 1997, or Revision 1, dated July 6, 2000: Inspect in accordance with paragraph (f) of this AD before the airplane has accumulated 10,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever is later.

(2) For airplanes that have not accomplished the inspection of the splice area for cracking as specified in Boeing Alert Service Bulletin 747-53A2390, dated July 31, 1997, or Revision 1, dated July 6, 2000: Inspect in accordance with paragraph (f) of this AD before the airplane has accumulated 10,000 total flight cycles, or within 250 flight cycles after the effective date of this AD, whichever is later.

Reporting Requirement

(g) If any damage is found to any longeron extension fitting during the inspection required by paragraph (f) of this AD: Submit a report of the findings of the inspection required by paragraph (f) of this AD to the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; fax [phone], at the applicable time specified in paragraph (g)(1) or (g)(2) of this AD. The report must include the airplane serial number and line number, identify the operator of the affected airplane, specify whether the cracking is within the limits given in the service bulletin, and specify if the cracking was found on the left or right or both longeron extension fittings. Under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number 2120-0056.

(1) If the inspection was done on or after the effective date of this AD: Submit the report within 20 days after the inspection.

(2) If the inspection was accomplished prior to the effective date of this AD: Submit the report within 20 days after the effective date of this AD.

Alternative Methods of Compliance (AMOCs)

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

(2) 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.

(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 January 27, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.