02-29675. Airworthiness Directives; Boeing Model 747-100, -200B, -200C, -200F, -300, -400, -400F, and 747SR Series Airplanes, Equipped with a Main Deck Side Cargo Door (MDSCD) Manufactured by Boeing

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 747-100, -200B, -200C, -200F, -300, -400, -400F, and 747SR series airplanes equipped with a MCSCD manufactured by Boeing. This action requires repetitive inspections for cracking of the lower lobe panel of the fuselage skin of the aft cargo bay, and repair if necessary. This action is necessary to find and fix cracking of the skin, which could lead to reduced structural integrity of the side cargo door cutout of the main deck, and result in rapid depressurization of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Effective December 11, 2002.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of December 11, 2002.

Comments for inclusion in the Rules Docket must be received on or before January 27, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-270-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-270-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Ivan Li, 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:

The FAA recently received a report of cracking of the lower lobe panel of the fuselage skin of the aft cargo bay, between Station (STA) 1720 and 1740, on a Model 747-200F series airplane. The crack was 11.6 inches long and was located below the stringer 34L lap joint and the upper fastener row of the external reinforcing doubler of the cargo door cutout of the main deck. The airplane had accumulated 18,688 total flight cycles and 81,902 total flight hours. Subsequent examination and analysis of the cracked skin revealed that the crack originated from scratches in the skin exterior surface at multiple locations. Such cracking, if not found and fixed, could lead to reduced structural integrity of the side cargo door cutout of the main deck, and result in rapid depressurization of the airplane.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 747-53A2487, Revision 1, dated October 31, 2002, which describes procedures for repetitive internal detailed or eddy current inspections for cracking of the lower lobe panel of the fuselage skin of the aft cargo bay at section 46, below stringer 34L, from STA 1640 through 1740 inclusive. If any cracking is found, the service bulletin specifies contacting the manufacturer for repair information. The service bulletin also recommends that operators submit inspection findings to Boeing following each inspection. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

Explanation of the Requirements of the Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD requires accomplishment of the actions specified in the service bulletin described previously, except as discussed below.

Differences Between AD and Service Bulletin

The service bulletin specifies that the manufacturer may be contacted for disposition of repairs; however, this AD requires all repairs to be accomplished per a method approved by the FAA, or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the Manager, Seattle Aircraft Certification Office, to make such findings.

Although the service bulletin recommends that operators report findings to the manufacturer after each inspection, this AD does not include such a reporting requirement.

Interim Action

This is considered to be interim action. The manufacturer has advised that it currently is developing a modification that will address the unsafe condition addressed by this AD. Once this modification is developed, approved, and available, we may consider additional rulemaking.

Determination of Rule's Effective Date

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2002-NM-270-AD.” The postcard will be date stamped and returned to the commenter.

Regulatory Impact

The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a “significant regulatory action” under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness directive:

2002-23-15 Boeing: Amendment 39-12959. Docket 2002-NM-270-AD.

Applicability: Model 747-100, -200B, -200C, -200F, -300, -400, -400F, and 747SR series airplanes; equipped with a main deck side cargo door manufactured by Boeing; certificated in any category.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To find and fix cracking of the lower lobe panel of the fuselage skin of the aft cargo bay, which could lead to reduced structural integrity of the side cargo door cutout of the main deck, and result in rapid depressurization of the airplane, accomplish the following:

Repetitive Inspections

(a) Do either an internal detailed or eddy current inspection to find cracking of the lower lobe panel of the fuselage skin of the aft cargo bay, below stringer 34L, from Station (STA) 1640 through 1740 inclusive, per Boeing Alert Service Bulletin 747-53A2487, Revision 1, dated October 31, 2002. Do the initial inspection at the time shown in paragraph (a)(1) or (a)(2) of this AD, as applicable. If the initial inspection was a detailed inspection, repeat that inspection at least every 50 flight cycles; if the initial inspection was an eddy current inspection, repeat that inspection at least every 250 flight cycles; as applicable. Although the service bulletin references a reporting requirement in paragraph 1.D., such reporting is not required by this AD.

Note 2:

For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

(1) For airplanes on which the main deck side cargo door (MDSCD) was installed after the date of manufacture of the airplane: Do the inspection within 10,000 flight cycles after installation of the MDSCD, or within 90 days after the effective date of this AD, whichever is later.

(2) For airplanes on which the MDSCD was installed before the date of manufacture of the airplane: Do the inspection prior to the accumulation of 15,000 total flight cycles on the airplane, or within 90 days after the effective date of this AD, whichever is later.

(b) Inspections done before the effective date of this AD per Boeing Alert Service Bulletin 747-53A2487, dated October 24, 2000; are considered acceptable for compliance with paragraph (a) of this AD.

Repair

(c) If any crack is found during any inspection required by paragraph (a) of this AD: Before further flight, repair per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD.

Alternative Methods of Compliance

(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

Note 3:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

Special Flight Permits

(e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Incorporation by Reference

(f) Unless otherwise provided by this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 747-53A2487, Revision 1, dated October 31, 2002. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplane Group, PO Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(g) This amendment becomes effective on December 11, 2002.

Issued in Renton, Washington, on November 14, 2002.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.