04-4928. Airworthiness Directives; Boeing Model 767-200, -300, and -300F Series Airplanes

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 767-200, -300, and -300F series airplanes. This proposal would require inspections to detect cracking or corrosion of the fail-safe straps between the side fitting of the rear spar bulkhead at body station 955 and the skin; and follow-on/corrective actions. This action is necessary to detect and correct fatigue cracking or corrosion of the fail-safe straps, which could result in cracking of adjacent structure and consequent reduced structural integrity of the fuselage. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by April 19, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-263-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-263-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 2002-NM-263-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. 2002-NM-263-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports of cracked and/or corroded fail-safe straps at body station (BS) 955 on Boeing Model 767-200 series airplanes. The airplane manufacturer has found that such fatigue cracking is due to residual tension in the fail-safe strap. Fatigue cracking or corrosion of the fail-safe straps between the side fitting of the rear spar bulkhead at BS 955 and the skin, if not detected and corrected, could result in cracking of adjacent structure and consequent reduced structural integrity of the fuselage.

The fail-safe strap on certain Model 767-300 and -300F series airplanes are identical to those on the affected Model 767-200 series airplanes. Therefore, all of these models may be subject to the same unsafe condition.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 767-53A0100, dated September 26, 2002. The service bulletin describes procedures for an initial detailed inspection and eddy current inspection to detect cracking or corrosion of the fail-safe straps between the side fitting of the rear spar bulkhead at BS 955 and the skin; and follow-on/corrective actions. The follow-on/corrective actions include performing repetitive detailed and eddy current inspections or contacting Boeing for repair and repeat inspection information, as applicable.

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.

Differences Between Proposed Rule and Service Bulletin

We have determined to simplify the complex compliance time specified in the service bulletin in order to reduce potential confusion and inadvertent non-compliances. We find that a compliance time of “prior to the accumulation of 15,000 total flight cycles, or within 3,000 flight cycles after the effective date of the AD, whichever occurs later” will provide an acceptable level of safety.

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.

Interim Action

This is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.

Cost Impact

There are approximately 833 airplanes of the affected design in the worldwide fleet. The FAA estimates that 354 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 2 work hours per airplane to accomplish the proposed inspections, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $46,020, or $130 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.

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 2002-NM-263-AD.

Applicability: All Model Boeing Model 767-200, -300, and -300F series airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To detect and correct fatigue cracking or corrosion of the fail-safe straps between the side fitting of the rear spar bulkhead at body station (BS) 955 and the skin, which could result in cracking of adjacent structure and consequent reduced structural integrity of the fuselage, accomplish the following:

Inspections and Follow-On/Corrective Actions

(a) Except as provided by paragraph (b) of this AD, prior to the accumulation of 15,000 total flight cycles, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, perform a detailed inspection and eddy current inspection to detect cracking or corrosion of the fail-safe straps between the side fitting of the rear spar bulkhead at BS 955 and the skin, per Figure 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-53A0100, dated September 26, 2002.

Note 1:

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) If no crack or corrosion is found, repeat the inspections thereafter at intervals not to exceed 6,000 flight cycles or 36 months, whichever occurs first.

(2) If any crack or corrosion is found, before further flight, repair per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or 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, the approval must specifically reference this AD.

(b) For airplanes that have replaced the failsafe strap before the effective date of this AD: Do the actions required by paragraph (a) of this AD within 12,000 flight cycles after accomplishing the replacement.

Alternative Methods of Compliance

(c)(1) In accordance with 14 CFR 39.19, the Manager, Seattle 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 February 26, 2004.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.