04-7286. Airworthiness Directives; Boeing Model 767-300 and 767-300F Series Airplanes Equipped With General Electric or Pratt & Whitney Engines

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 certain Boeing Model 767-300 and 767-300F series airplanes equipped with General Electric or Pratt & Whitney engines. This proposal would require reworking the wing-to-strut diagonal braces and the aft pitch load fittings of the wings, and reinstalling the diagonal braces with new fuse pins and associated hardware. For certain airplanes, this proposal would require replacing the bushings of the aft pitch load fittings, installing new fuse pins, and reworking the fittings, as applicable. This action is necessary to prevent undetected loss of the diagonal brace fuse pins of the wings and consequent increased loads in other wing-to-strut joints, which could result in separation of the struts and engines from the wings. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by May 17, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-186-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. 2003-NM-186-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 Airplanes, 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:

Suzanne Masterson, 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

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 2003-NM-186-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. 2003-NM-186-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received a report that, following the loss of the upper link or midspar load paths, the fuse pin of a wing-to-strut diagonal brace of the wing for certain Boeing Model 767-300 and 767-300F series airplanes equipped with General Electric or Pratt & Whitney engines does not meet the minimum damage tolerance requirements. The fuse pin of the diagonal brace showed early fatigue cracks during damage tolerance testing. The load path of diagonal braces is part of the engine strut-to-wing load path. Early fatigue cracks of the fuse pins of the diagonal braces, if not corrected, could lead to loss of the fuse pins and consequent increased loads in other wing-to-strut joints, which could result in separation of the struts and engines from the wings.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 767-54A0096, Revision 2, dated December 18, 2003. The alert service bulletin describes procedures for removing and reworking the wing-to-strut diagonal braces of the wings, including replacing the end fittings of the braces with new fittings; reworking the aft pitch load fittings of the wings, including replacing the fitting bushings with new bushings; and reinstalling the diagonal braces with new fuse pins and associated hardware. For certain airplanes, the alert service bulletin describes procedures for replacing the bushings of the aft pitch load fittings with new bushings, reworking the aft pitch load fittings, and installing new fuse pins.

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

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 alert service bulletin described previously, except as described below.

Differences Between Proposed Rule and Service Bulletin

Boeing Alert Service Bulletin 767-54A0096, Revision 2, dated December 18, 2003, specifies a compliance time of “within six (6) years or 12,000 flight-cycles from the airplane delivery date, whichever is first, or if beyond this threshold, within 18 months from the issue date of Revision 2 to this service bulletin,” for the proposed removal and rework.

However, this proposed AD would require accomplishment of the proposed removal and rework at the later of the following times:

• Prior to the accumulation of 12,000 total flight cycles, or within 6 years after the date of issuance of the original Airworthiness Certificate or the Export Certificate of Airworthiness, whichever occurs first.
• Within 18 months after the effective date of this AD.

This decision is based on our determination that “date of delivery” may be interpreted differently by different operators. We find that our proposed terminology is generally understood within the industry and records will always exist that establish these dates with certainty.

Cost Impact

There are approximately 92 airplanes of the affected design in the worldwide fleet. The FAA estimates that 53 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately between 14 and 24 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $65 per work hour. Required parts would cost approximately $18,704 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be between $1,039,542 and $1,073,992, or between $19,614 and $20,264 per airplane.

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. The manufacturer may cover the cost of replacement parts associated with this proposed AD, subject to warranty conditions. Manufacturer warranty remedies may also be available for labor costs associated with this proposed AD. As a result, the costs attributable to the proposed AD may be less than stated above.

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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

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:

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:

Boeing: Docket 2003-NM-186-AD.

Applicability: Model 767-300 and 767-300F series airplanes, equipped with General Electric or Pratt & Whitney engines; as listed in Boeing Alert Service Bulletin 767-54A0096, Revision 2, dated December 18, 2003; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent undetected loss of the diagonal brace fuse pins of the wings and consequent increased loads in other wing-to-strut joints, which could result in separation of the struts and engines from the wings, accomplish the following:

Rework and Reinstallation

(a) Remove and rework the diagonal braces of the engine nacelles/pylons, rework the aft pitch load fittings of the wings, and reinstall the diagonal braces with new fuse pins and associated hardware by doing all actions specified in steps 3.B.1. through 3.B.11. inclusive, of the Work Instructions of Boeing Alert Service Bulletin 767-54A0096, Revision 2, dated December 18, 2003. Do the actions per the service bulletin. Do the actions at the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD.

(1) Prior to the accumulation of 12,000 total flight cycles, or within 6 years after the date of issuance of the original Airworthiness Certificate or the export Certificate of Airworthiness, whichever occurs first.

(2) Within 18 months after the effective date of this AD.

Additional Work For Airplanes Modified per the Original Issue of the Service Bulletin

(b) For airplanes modified per Boeing Service Bulletin 767-54-0096, dated August 31, 2000: Within 18 months after the effective date of this AD, replace the bushings of the aft pitch load fittings of the wings with new bushings, rework the aft pitch load fittings, and install new fuse pins, by doing all actions specified in steps 3.B.1. through 3.B.10. inclusive, of the Additional instructions of Boeing Alert Service Bulletin 767-54A0096, Revision 2, dated December 18, 2003.

Alternative Methods of Compliance

(c)(1) In accordance with 14 CFR 39.19, the Manager, Seattle Aircraft Certification Office (ACO), FAA, 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 any repair required by this AD, if it is approved by a Boeing Company Designated Engineering Representative who has been authorized by the Manager, Seattle ACO, to make such findings.

Issued in Renton, Washington, on March 25, 2004.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft certification Service.