E8-9894. Airworthiness Directives; Boeing Model 747-200F, 747-300, 747-400, and 747-400D Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are adopting a new airworthiness directive (AD) for certain Boeing Model 747-200F, 747-300, 747-400, and 747-400D series airplanes. This AD requires a detailed inspection to detect missing fasteners from the shear clip at a certain stub frame to auxiliary sill joint, and applicable related investigative and corrective actions. This AD results from reports of missing fasteners from the shear clip of the stub frame to auxiliary sill joint and cracking of the adjacent exterior skin and internal doubler. We are issuing this AD to ensure that fasteners are installed in the shear clip of the stub frame to auxiliary sill joint. Missing fasteners could result in cracks in the adjacent exterior skin and internal doubler, which can propagate and result in loss of structural integrity and sudden in-flight decompression of the airplane.

DATES:

This AD is effective June 12, 2008.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of June 12, 2008.

ADDRESSES:

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 AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (telephone [phone]) is the Document Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT:

Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Boeing Model 747-200F, 747-300, 747-400, and 747-400D series airplanes. That NPRM was published in the Federal Register on October 17, 2007 (72 FR 58768). That NPRM proposed to require a detailed inspection to detect missing fasteners from the shear clip at a certain stub frame to auxiliary sill joint, and applicable related investigative and corrective actions.

New Service Bulletin Revision

Since we issued the NPRM, we have reviewed Boeing Service Bulletin 747-53A2685, Revision 1, dated March 13, 2008. Revision 1 clarifies certain figures and part and material content. No additional work is necessary for airplanes on which the actions have been done in accordance with Boeing Alert Service Bulletin 747-53A2685, dated May 31, 2007 (referred to as the appropriate source of service information for accomplishing the actions specified in the NPRM). We have revised paragraphs (c), (f), and (g) of this AD to refer to Boeing Service Bulletin 747-53A2685, Revision 1, dated March 13, 2008. We have added a new paragraph (h) of this AD to give credit for actions done before the effective date of this AD according to Boeing Alert Service Bulletin 747-53A2685, dated May 31, 2007, and redesignated subsequent paragraphs of the AD accordingly.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received from two commenters. Boeing requested that Boeing Service Bulletin 747-53A2685, Revision 1, dated March 13, 2008, be used instead of Boeing Alert Service Bulletin 747-53A2685, dated May 31, 2007. All Nippon Airways requested clarification of technical information in the NPRM. These requests have been addressed in Revision 1 of the service bulletin, which is cited in the final rule.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD.

Costs of Compliance

There are about 98 airplanes of the affected design in the worldwide fleet. This AD affects about 8 airplanes of U.S. registry. The required actions 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 AD for U.S. operators is $640, or $80 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

This AD will not have federalism implications under Executive Order 13132. This AD will 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 this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Is not a “significant rule” under 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

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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 FAA amends § 39.13 by adding the following new AD:

2008-09-20 Boeing: Amendment 39-15501. Docket No. FAA-2007-0045; Directorate Identifier 2007-NM-169-AD.

Effective Date

(a) This airworthiness directive (AD) is effective June 12, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 747-200F, 747-300, 747-400, and 747-400D series airplanes, certificated in any category; as identified in Boeing Service Bulletin 747-53A2685, Revision 1, dated March 13, 2008.

Unsafe Condition

(d) This AD results from two reports of cracks found in the exterior skin and internal doubler adjacent to the shear clip at the stub frame to auxiliary sill joint at stringer 30 (left and right sides), body station (BS) 488. In addition, on one of the airplanes, seven fasteners were missing from the shear clip on the left side of the airplane. The cause of the missing fasteners has been attributed to a manufacturing process error. We are issuing this AD to ensure fasteners in the shear clip of the stub frame to auxiliary sill joints (left and right sides) are installed. Missing fasteners could result in cracks in the adjacent exterior skin and internal doubler, which can propagate and result in loss of structural integrity and sudden in-flight decompression 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.

Inspection and Applicable Related Investigative and Corrective Actions

(f) At the applicable compliance time and repeat intervals listed in Tables 1 and 2 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2685, Revision 1, dated March 13, 2008; except where 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: Do the inspection and applicable related investigative and corrective actions by accomplishing all the applicable actions specified in the Accomplishment Instructions of the service bulletin, except as provided by paragraph (g) of this AD.

Repair of Cracks

(g) If any crack is found during any inspection required by this AD, and Boeing Service Bulletin 747-53A2685, Revision 1, dated March 13, 2008, specifies to contact Boeing for appropriate action: Before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (i) of this AD.

Credit for Actions Done Using the Previous Service Information

(h) Actions accomplished before the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-53A2685, dated May 31, 2007, are considered acceptable for compliance with the corresponding actions specified in paragraph (f) of this AD.

Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with 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.

Material Incorporated by Reference

(j) You must use Boeing Service Bulletin 747-53A2685, Revision 1, dated March 13, 2008, to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

(3) You may review copies of the service information incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Issued in Renton, Washington, on April 23, 2008.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.