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Proposed Rule

Airworthiness Directives; Boeing Model 747 Series Airplanes

Document Details

Information about this document as published in the Federal Register.

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AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Boeing Model 747 series airplanes. This proposal would require repetitive inspections of the nacelle strut-to-wing attachment structure, and repetitive overhaul of the diagonal brace and spring beam load paths, to maintain damage tolerance requirements and ensure long-term structural integrity; and follow-on and corrective actions if necessary. This action is necessary to ensure the structural integrity of the strut-to-wing load path and prevent separation of the strut and engine from the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by November 3, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-279-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 (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-279-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 or 2000 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.

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FOR FURTHER INFORMATION CONTACT:

Tamara Anderson, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6421; fax (425) 917-6590.

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SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

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 proposed 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 proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NM-279-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-279-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Related Rulemaking

This proposed AD is related to the following rulemaking actions, which require accomplishment of the actions in the concurrent service bulletins recommended in Boeing Alert Service Bulletin 747-54A2182, dated July 12, 2001:

AD 95-13-06, amendment 39-9286 (60 FR 33338, June 28, 1995); correction to AD 95-13-06 (60 FR 37500, July 20, 1995). That AD references Boeing Alert Service Bulletin 747-54A2156, dated December 2, 1994, for accomplishment of the specified actions. That AD is applicable to certain Boeing Model 747 series airplanes equipped with General Electric Model CF6-80C2 series engines or Pratt & Whitney Model PW4000 series engines, and requires modification of the nacelle strut and wing structure, inspections and checks to detect discrepancies, and correction of discrepancies.

AD 95-13-05, amendment 39-9285 (60 FR 33333, June 28, 1995); correction to AD 95-13-05 (60 FR 35452, July 7, 1995). That AD references Boeing Alert Service Bulletin 747-54A2157, dated January 12, 1995, for accomplishment of the specified actions. That AD is applicable to Boeing Model 747 series airplanes equipped with Rolls Royce Model RB211 series engines, and requires modification of the nacelle strut and wing structure, inspections and checks to detect discrepancies, and correction of discrepancies.

AD 95-13-07, amendment 39-9287 (60 FR 33336, June 28, 1995). That AD references Boeing Alert Service Bulletin 747-54A2158, dated November 23, 1994, for accomplishment of the specified actions. That AD is applicable to certain Boeing Model 747 series airplanes equipped with General Electric Model CF6-45/50 or Pratt & Start Printed Page 54681Whitney Model JT9D-70 series engines, and requires modification of the nacelle strut and wing structure, inspections and checks to detect discrepancies, and correction of discrepancies.

AD 95-10-16, amendment 39-9233 (60 FR 27008, May 22, 1995). That AD references Boeing Alert Service Bulletin 747-54A2159, dated November 3, 1994, for accomplishment of the specified actions. That AD is applicable to Boeing Model 747 series airplanes equipped with Pratt & Whitney Model JT9D series engines (excluding Model JT9D-70 engines), and requires modification of the nacelle strut and wing structure, inspections and checks to detect discrepancies, and correction of discrepancies.

Actions Since Issuance of Previous Rulemaking

Since issuance of the ADs specified previously, there have been equivalent production changes to airplanes having line numbers 1047 and subsequent. The strut and wing modifications required by those ADs, in addition to the equivalent production changes, increase the level of safety for damage tolerance and structural fail-safe capability of the new and modified structure. The actions specified in this proposed AD are intended to provide repetitive inspections and overhaul of the nacelle strut-to-wing attachment structure to maintain damage tolerance and ensure long-term structural integrity for all Model 747 series airplanes.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 747-54A2182, dated July 12, 2001, which describes procedures for repetitive baseline and supplemental inspections for discrepancies (including cracks, corrosion, or damage; and loose, missing, or broken fasteners) of the nacelle strut-to-wing attachment structure, and follow-on and corrective actions if necessary. The follow-on actions include a one-time visual inspection of all side link fuse pin installations to verify that the correct fuse pins are installed; a one-time detailed inspection of all strut-to-wing attachment joints to verify correct installation of hardware; and repetitive inspections, as applicable; and an inspection of the strut-to-wing attachment structure for damage and to verify structural integrity. The service bulletin recommends contacting the manufacturer if any damage is found or structural integrity of the strut-to-wing structure cannot be verified.

The service bulletin also describes procedures for repetitive overhaul of the diagonal brace and spring beam load paths, and nondestructive testing of the fuse pin and secondary pin.

Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

The service bulletin also recommends prior accomplishment of Boeing Alert Service Bulletins 747-54A2156, 747-54A2157, 747-54A2158, and 747-54A2159. Those service bulletins are referenced for accomplishment of the actions required by the related rulemaking described previously.

Explanation of Requirements of Proposed Rule

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

Difference Between Service Bulletin and This Proposed AD

The service bulletin specifies that the manufacturer may be contacted for disposition of certain repair conditions; however, this proposed AD would require the repair of those conditions 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.

Changes to 14 CFR Part 39/Effect on the Proposed AD

On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. Because we have now included this material in part 39, we no longer need to include it in each individual AD; however, this AD identifies the office authorized to approve alternative methods of compliance.

Change to Labor Rate Estimate

We have reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.

Cost Impact

There are approximately 991 airplanes of the affected design in the worldwide fleet. The FAA estimates that 187 airplanes of U.S. registry would be affected by this proposed AD.

It would take approximately 280 work hours per airplane to accomplish the repetitive baseline, supplemental, and fuse pin inspections at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed inspections on U.S. operators is estimated to be $3,403,400, or $18,200 per airplane, per inspection cycle.

It would take approximately 48 work hours per airplane to accomplish the repetitive overhaul of the diagonal brace at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed overhaul on U.S. operators is estimated to be $583,440, or $3,120 per airplane, per overhaul.

It would take approximately 40 work hours per airplane to accomplish the repetitive overhaul of the spring beam at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the proposed overhaul on U.S. operators is estimated to be $486,200, or $2,600 per airplane, per overhaul.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not Start Printed Page 54682a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

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List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Boeing: Docket 2001-NM-279-AD.

Applicability: All Model 747 series airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To ensure the structural integrity of the strut-to-wing load path and prevent separation of the strut and engine from the airplane, accomplish the following:

Compliance Times

(a) Where the compliance times for the initial and repetitive baseline and supplemental inspections in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2182, dated July 12, 2001, specify a compliance time interval calculated “from the release of this service bulletin,” this AD requires compliance within the interval specified in the service bulletin “after the effective date of this AD.”

Inspections/Follow-on Actions

(b) Do the initial and repetitive baseline and supplemental inspections of the nacelle strut-to-wing attachment structure for discrepancies (including cracks, corrosion, or damage; and loose, missing, or broken fasteners), and do the applicable follow-on actions; by doing all the actions in Part 1 through Part 9 of the Work Instructions of Boeing Alert Service Bulletin 747-54A2182, dated July 12, 2001. Do the inspections (including inspections for correct installation of hardware and part numbers) and follow-on actions at the applicable times specified in Figure 1 of the service bulletin.

(c) Do the initial and repetitive overhauls of the diagonal brace and spring beam load paths by doing all the actions in Part 10 and Part 11 of the Work Instructions of Boeing Alert Service Bulletin 747-54A2182, dated July 12, 2001. Do the initial and repetitive overhauls at the applicable times specified in Part 10 and Part 11 of the service bulletin.

(d) Do the initial and repetitive inspections of the fuse pins and secondary pins of the strut-to-wing attachment by doing all the actions in Part 12 of the Work Instructions of Boeing Alert Service Bulletin 747-54A2182, dated July 12, 2001. Do the inspections at the times specified in Part 12 of the service bulletin.

Corrective Actions

(e) If any discrepancy is found during any inspection required by this AD: Before further flight, do all applicable corrective actions specified in Part 1 through Part 12 of the Work Instructions of Boeing Alert Service Bulletin 747-54A2182 dated July 12, 2001. Do the applicable corrective actions per the service bulletin. If the service bulletin specifies to contact the manufacturer for appropriate action: 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 (DER) who has been authorized by the Manager, Seattle ACO, to make such findings.

Alternative Methods of Compliance

(f)(1) In accordance with 14 CFR 39.19, the Manager, Seattle ACO, is authorized to approve alternative methods of compliance (AMOCs) for this AD.

(2) An AMOC that provides an acceptable level of safety may be used for a repair required by this AD, if it is approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings.

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Issued in Renton, Washington, on September 11, 2003.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 03-23820 Filed 9-17-03; 8:45 am]

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