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Proposed Rule

Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200F, 747-200C, 747-300, 747SR, and 747SP Series Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

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 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200F, 747-200C, 747-300, 747SR, and 747SP series airplanes. This proposal would require repetitive inspections for discrepancies of the structure near and common to the upper chord and splice fittings of the rear spar of the wing, and repair if necessary. This proposal also would provide for an optional modification that, if accomplished, would terminate the repetitive inspection requirement, but would necessitate eventual post-modification inspections. This action is necessary to find and fix fatigue cracking of structure near and common to the upper chord and splice fittings of the rear spar of the wing, which could result in loss of structural integrity of Start Printed Page 36507the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by August 4, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-238-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-238-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, PO Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

Start Further Info

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.

End Further Info End Preamble Start Supplemental Information

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-238-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-238-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports indicating that fatigue cracking has been found on the wing on several Boeing Model 747-100 and 747-200B series airplanes. The cracking is adjacent and common to the upper chord and splice fittings of the rear spar of the wing. Such cracking, if not corrected, could result in loss of structural integrity of the airplane.

The subject area on Model 747-100B, 747-100B SUD, 747-200F, 747-200C, 747-300, 747SR, and 747SP series airplanes is similar to that on the affected Model 747-100 and 747-200B series airplanes. Therefore, all of these airplanes may be subject to the same unsafe condition.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003, which describes procedures for repetitive inspections for discrepancies of the structure near and common to the upper chord and splice fittings of the rear spar of the wing, and repair if necessary. The inspection procedures include removing existing bolts; performing an ultrasonic or magnetic particle inspection for cracking of removed H-11 bolts; performing a detailed inspection of all other removed bolts for cracking, corrosion, or damage; replacing cracked, corroded, or damaged bolts with new improved bolts; removing any installed repair bushings; performing an open-hole high frequency eddy current (HFEC) inspection for cracking of the bolt holes; installing new bushings if necessary; reinstalling bolts that are not cracked, corroded, or damaged; torquing the nuts; performing a detailed inspection of the shim between the kick fitting and bulkhead strap for cracking or migration; and replacing the shim with a new shim if necessary. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

The service bulletin also describes procedures for an optional modification, which involves removing installed repair bushings, performing an open-hole HFEC inspection for cracking of the bolt holes, repairing any cracking that is found, oversizing bolt holes, and installing new improved bolts. Accomplishment of the optional modification eliminates the need for the repetitive inspections described previously, but necessitates eventual post-modification inspections. The post-modification inspections involve procedures similar to those for the pre-modification inspections, which were 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 under the heading “Differences Between Proposed Rule and Service Bulletin.”

Clarification of Credit for Actions Accomplished Previously

Flag Note 1 of the logic diagram in Figure 1 of Boeing Alert Service Bulletin 747-57A2314, Revision 1, specifies that, for certain fastener holes on certain airplanes, an inspection per Figure 4, Step 14, of Boeing Service Bulletin 747-57-2110 is considered acceptable for compliance with the initial inspection specified in paragraph (a) of this proposed AD. We have reviewed and approved Boeing Service Bulletin 747-57-2110, Revision 6, dated November 21, 1991; and Revision 7, dated April 23, 1998; and have determined that accomplishment of an initial inspection before the effective date of this AD per Figure 4, Step 14, of one of those revisions of the service bulletin would provide an acceptable level of safety. Start Printed Page 36508We have also reviewed Boeing Service Bulletin 747-57-2110, Revision 3, dated February 19, 1987; Revision 4, dated May 26, 1988; and Revision 5, dated October 26, 1989. We have determined that accomplishment of an initial inspection before the effective date of this AD per Figure 4, Step 9, of one of those revisions of the service bulletin would provide an acceptable level of safety. The first repeat inspection per paragraph (b) of this proposed AD would be required to be accomplished at the applicable interval established in paragraph (b) of this proposed AD after the most recent inspection per Figure 4, Step 14, of Boeing Service Bulletin 747-57-2110, Revision 6 or 7; or Figure 4, Step 9, of Boeing Service Bulletin 747-57-2110, Revision 3, 4, or 5.

Differences Between Proposed Rule and Service Bulletin

Operators should note that, although the service bulletin specifies that the manufacturer may be contacted for disposition of certain repair conditions, this proposal 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 FAA to make such findings.

Operators should also note that, although Appendix B of Boeing Alert Service Bulletin 747-57A2314, Revision 1, describes procedures for reporting discrepancies found during an inspection, this proposed AD would not require those actions.

Cost Impact

There are approximately 593 airplanes of the affected design in the worldwide fleet. The FAA estimates that 176 airplanes of U.S. registry would be affected by this proposed AD.

It would take approximately 8 work hours per airplane to accomplish the proposed inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the proposed inspection on U.S. operators is estimated to be $84,480, or $480 per airplane, per inspection cycle.

The cost impact figure discussed above is 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.

Should an operator elect to accomplish the optional terminating action that would be provided by this AD action, it would take approximately 22 work hours to accomplish it, at an average labor rate of $60 per work hour. The cost of required parts would be approximately $10,700 per airplane. Based on these figures, the cost impact of the optional terminating action would be approximately $12,020 per airplane.

If the optional terminating action provided by this AD action is accomplished, an eventual post-modification inspection would be necessary. That inspection would take approximately 8 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the post modification inspections would be approximately $480 per airplane, per inspection cycle.

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 a “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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

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:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

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

Start Authority

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

End Authority
[Amended]

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

Boeing: Docket 2001-NM-238-AD.

Applicability: All Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200F, 747-200C, 747-300, 747SR, and 747SP series airplanes; 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 (k) 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 fatigue cracking of structure near and common to the upper chord and splice fittings of the rear spar of the wing, which could result in loss of structural integrity of the airplane, accomplish the following:

Initial Inspections

(a) Perform inspections for discrepancies of the structure near and common to the upper chord and splice fittings of the rear spar of the wing, per Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003. The inspection procedures include removing existing bolts; performing an ultrasonic or magnetic particle inspection for cracking of removed H-11 bolts; performing a detailed inspection of all other removed bolts for cracking, corrosion, or damage; replacing cracked, corroded, or damaged bolts with new improved bolts; removing any installed repair bushings; performing an open-hole high frequency eddy current (HFEC) inspection for cracking of the bolt holes; installing new bushings, if necessary; reinstalling bolts that are not cracked, corroded, or damaged; torquing the nuts; performing a detailed inspection of the shim between the kick fitting and bulkhead strap for cracking or migration; and replacing the shim with a new shim if necessary, except as provided by paragraph (h) of this AD. Do the initial inspection at the time specified in paragraph (a)(1) or (a)(2) of this AD, whichever is later.

(1) Inspect at the earlier of the applicable times specified in the “Flights” and “Hours” columns under the heading “Initial Start Printed Page 36509Inspection Threshold” in Table 1 of Figure 1 of the service bulletin. Where the “Initial Inspection Threshold” column of Table 1 of Figure 1 of the service bulletin specifies “flights” and “hours,” for the purposes of this paragraph the numbers in that column are considered to be the airplane's total flight cycles and total flight hours.

(2) Inspect within 18 months after the effective date of 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.”

Repetitive Inspections

(b) Repeat the inspection required by paragraph (a) of this AD at intervals not to exceed the earlier of the times specified in the “Flights” and “Hours” columns under the heading “Repeat Inspection Intervals” in Table 1 of Figure 1 of Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003, until paragraph (d) of this AD is accomplished. Where the “Repeat Inspection Intervals” column of Table 1 of Figure 1 of the service bulletin specifies “flights” and “hours,” for the purposes of this paragraph, the figures in that column are considered to be the number of flight cycles and flight hours from the time of the most recent inspection per paragraph (a) or (b) of this AD, except as provided by paragraph (g) of this AD.

Repair

(c) If any cracking is found during any inspection required by paragraph (a) or (b) of this AD, before further flight, repair per the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003, except as provided by paragraph (h) of this AD.

Optional Modification

(d) Accomplishment of the modification specified in Part 4 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003, constitutes terminating action for the initial inspections required by paragraph (a) of this AD and the repetitive inspections required by paragraph (b) of this AD, provided that the repetitive post-modification inspections required by paragraph (e) of this AD are initiated at the applicable time. The modification procedures include removing installed repair bushings, performing an open-hole HFEC inspection for cracking of the bolt holes, repairing any cracking that is found, oversizing bolt holes, and installing new improved bolts.

Post-Modification Inspections

(e) For airplanes on which the optional modification specified in paragraph (d) of this AD is accomplished: At the earlier of the times specified in the “Flights” and “Hours” columns under the heading “Post Modification Threshold” in Table 2 of Figure 1 of Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003, perform a post-modification inspection per Part 5 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003. The inspection procedures include removing existing bolts; performing a detailed inspection of removed bolts for cracking, corrosion, or damage; replacing cracked, corroded, or damaged bolts with new bolts; removing any installed repair bushings; performing an open-hole HFEC inspection for cracking of the bolt holes; installing new bushings if necessary; reinstalling bolts that are not cracked, corroded, or damaged; torquing the nuts; performing a detailed inspection of the shim between the kick fitting and bulkhead strap for cracking or migration; and replacing the shim with a new shim if necessary; except as provided by paragraph (h) of this AD. Where the “Post Modification Inspection Threshold” column of Table 2 of Figure 1 of the service bulletin specifies “flights” and “hours,” for the purposes of this paragraph, the numbers in that column are considered to be the flight cycles and flight hours after accomplishment of the modification specified in paragraph (d) of this AD.

(1) Repeat the inspection at intervals not to exceed the earlier of the times specified in the “Flights” and “Hours” columns under the heading “Post Modification Repeat Inspection Intervals” in Table 2 of Figure 1 of the service bulletin. Where the “Post Modification Repeat Inspection Intervals” column of Table 2 of Figure 1 of the service bulletin specifies “flights” and “hours,” for the purposes of this paragraph, the numbers in that column are considered to be the flight cycles and flight hours since the most recent inspection per paragraph (e) or (e)(1) of this AD.

(2) If any cracking is found during any inspection required by paragraph (e) or (e)(1) of this AD, before further flight, repair per the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003, except as provided by paragraph (h) of this AD.

Actions Accomplished Per Previous Issue of Service Bulletin

(f) Inspections, repairs, or modifications accomplished before the effective date of this AD per Boeing Alert Service Bulletin 747-57A2314, including Appendix A and B, dated June 28, 2001, are considered acceptable for compliance with the corresponding action specified in this AD, except as provided by paragraph (h) of this AD.

(g) As specified in Flag Note 1 of the logic diagram in Figure 1 of Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003: An inspection accomplished before the effective date of this AD per Figure 4, Step 14, of Boeing Service Bulletin 747-57-2110, Revision 6, dated November 21, 1991; or Revision 7, dated April 23, 1998; is considered acceptable, as applicable, for compliance with the initial inspection required by paragraph (a) of this AD. An inspection accomplished before the effective date of this AD per Figure 4, Step 9, of Boeing Service Bulletin 747-57-2110, Revision 3, dated February 19, 1987; Revision 4, dated May 26, 1988; and Revision 5, dated October 26, 1989; is also considered acceptable, as applicable, for compliance with the initial inspection required by paragraph (a) of this AD. The first repeat inspection per paragraph (b) of this AD must be accomplished at the applicable interval established in paragraph (b) of this AD after the most recent inspection per Figure 4, Step 14, of Boeing Service Bulletin 747-57-2110, Revision 6 or 7; or Figure 4, Step 9, of Boeing Service Bulletin 747-57-2110, Revision 3, 4, or 5.

Exception to Instructions in Service Bulletin

(h) Where Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003, specifies to contact Boeing for appropriate action, before further flight, repair per a method approved by the Manager, Seattle ACO, or per data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved, the approval must specifically reference this AD.

(i) Although Appendix B of Boeing Alert Service Bulletin 747-57A2314, Revision 1, dated January 9, 2003, refers to a reporting requirement, such reporting is not required by this AD.

Parts Installation

(j) Except as provided by paragraphs (a) and (b) of this AD, as of the effective date of this AD, no person may install any alloy steel bolt in any location specified in this AD on any airplane listed in the applicability of this AD.

Alternative Methods of Compliance

(k) 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

(l) 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.

Start Signature

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

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 03-15324 Filed 6-17-03; 8:45 am]

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