Airworthiness directives: Boeing,

[Federal Register: August 6, 2004 (Volume 69, Number 151)]

[Proposed Rules]

[Page 47804-47806]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr06au04-17]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-18786; Directorate Identifier 2004-NM-26-AD]

RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 767-200, -300, and -300F series airplanes. This proposed AD would require repetitive high frequency eddy current inspections and detailed inspections of the left and right butt line (BL) 25 vertical chords for cracks, and corrective actions if necessary. This proposed AD is prompted by findings of cracks in the fillet radii of the left and right BL 25 vertical chords common to the nose wheel well bulkhead at station 287. We are proposing this AD to detect and correct cracks in the left and right BL 25 vertical chords, which could grow downward into a critical area that serves as a primary load path for the nose landing gear (NLG) and result in the collapse of the NLG during landing.

DATES: We must receive comments on this proposed AD by September 20, 2004.

ADDRESSES: Use one of the following addresses to submit comments on this proposed AD.

DOT Docket Web site: Go to http://dms.dot.gov and follow

the instructions for sending your comments electronically.

Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your

comments electronically.

Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC 20590.

By fax: (202) 493-2251.

Hand Delivery: room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

You can get the service information identified in this proposed AD from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

You may examine the contents of this AD docket on the Internet at http://dms.dot.gov, or at the Docket Management Facility, U.S.

Department of Transportation, 400 Seventh Street, SW., room PL-401, on the plaza level of the Nassif Building, Washington, DC.

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 (425) 917-6441; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

The FAA has implemented new procedures for maintaining AD dockets electronically. As of May 17, 2004, new AD actions are posted on DMS and assigned a docket number. We track each action and assign a corresponding directorate identifier. The DMS AD docket number is in the form ``Docket No. FAA-2004-99999.'' The Transport Airplane Directorate identifier is in the form ``Directorate Identifier 2004-NM- 999-AD.'' Each DMS AD docket also lists the directorate identifier (``Old Docket Number'') as a cross-reference for searching purposes.

Comments Invited

We invite you to submit any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include ``Docket No. FAA-2004-18786; Directorate Identifier 2004-NM-26-AD'' in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments submitted by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will

also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

We are reviewing the writing style we currently use in regulatory documents.

[[Page 47805]]

We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications that affect you. You can get more information about plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.Examining the Docket

You may examine the AD docket in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

We have received a report of two operators finding cracks in the fillet radii of the left and right butt line (BL) 25 vertical chords, common to the nose wheel well bulkhead at station 287, on several Boeing Model 767-300 series airplanes. Stress corrosion was determined to have caused the cracks. This condition, if not corrected, could grow downward into a critical area that serves as a primary load path for the nose landing gear (NLG) and result in the collapse of the NLG during landing.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 767-53A0113, dated February 26, 2004. The service bulletin describes procedures for repetitive high frequency eddy current inspections (HFEC) and detailed inspections of the left and right BL 25 vertical chords common to the nose wheel well bulkhead at station 287 for cracks, and corrective actions if necessary. The corrective action includes repairing any damaged BL 25 vertical chord or contacting the manufacturer for repair instructions, as applicable. We have determined that accomplishment of the actions specified in the service bulletin will adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. Therefore, we are proposing this AD, which would require repetitive HFEC inspections and detailed inspections of the left and right BL 25 vertical chords common to the nose wheel well bulkhead at station 287 for cracks, and corrective actions if necessary. The proposed AD would require you to use the service information described previously to perform these actions, except as discussed under ``Difference Between the Proposed AD and the Service Bulletin.''

Differences Between the Proposed AD and the Service Bulletin

The service bulletin specifies that you may contact the manufacturer for instructions on repairing certain conditions. This proposed AD, however, would require you to repair those conditions using a method approved by the FAA, or with 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.

Clarification of Inspection Terminology

In this proposed AD, the ``detailed visual inspection'' specified in the service bulletin is referred to as a ``detailed inspection.'' We have included the definition for a detailed inspection in a note in this proposed AD.

Clarification Between Proposed Rule and the Service Bulletin

The service bulletin specifies a compliance time of 6 years in service, or within 18 months from the release date of the service bulletin. However, paragraph (g) of this proposed AD specifies the compliance time as the later of the following: (1) within 72 months since the date of issuance of the original Airworthiness Certificate or the date of issuance of the original Export Certificate of Airworthiness, or (2) within 18 months after the effective date of this AD. This decision is based on our determination that ``years in service'' 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.

Costs of Compliance

This proposed AD would affect about 743 airplanes worldwide and 312 airplanes of U.S. registry. The proposed actions would take about 8 work hours per airplane, at an average labor rate of $65 per work hour. No parts are required. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $162,240, or $520 per airplane, per inspection cycle.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify that the 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. 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.

   We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

   List of Subjects in 14 CFR Part 39

   Air transportation, Aircraft, Aviation safety, Safety.

   The Proposed Amendment

   Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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.

   Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD):

   Boeing: Docket No. FAA-2004-18786; Directorate Identifier 2004-NM- 26-AD.

   Comments Due Date

   (a) The Federal Aviation Administration (FAA) must receive comments on this AD action by September 20, 2004.

   Affected ADs

   (b) None.

   Applicability

   (c) This AD applies to Boeing Model 767-200, -300, and -300F series airplanes, certificated in any category; as listed in Boeing Alert Service Bulletin 767-53A0113, dated February 26, 2004.

   Unsafe Condition

   (d) This AD was prompted by findings of cracks in the fillet radii of the left and right

   [[Page 47806]]

   butt line (BL) 25 vertical chords common to the nose wheel well bulkhead at station 287. We are issuing this AD to detect and correct cracks in the left and right BL 25 vertical chords, which could grow downward into a critical area that serves as a primary load path for the nose landing gear (NLG) and result in the collapse of the NLG during landing.

   Compliance

   (e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

   Service Bulletin Reference

   (f) The term ``service bulletin,'' as used in this AD, means the Accomplishment Instructions of Boeing Alert Service Bulletin 767- 53A0113, dated February 26, 2004.

   Initial Inspections

   (g) At the later of the compliance times specified in paragraphs (g)(1) and (g)(2) of this AD: Do a high frequency eddy current inspection and a detailed inspection of the left and right BL 25 vertical chords common to the nose wheel well bulkhead at station 287 for cracks, in accordance with the service bulletin.

   (1) Within 72 months since the date of issuance of the original Airworthiness Certificate or the date of issuance of the original Export Certificate of Airworthiness.

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

   Note 1: For the purposes of this AD, a detailed inspection is: ``An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.''

   No Cracks Found

   (h) For any BL 25 vertical chord in which no crack is found during any inspection required by paragraph (g) of this AD: Thereafter at intervals not to exceed 48 months, repeat the inspections required by paragraph (g) of this AD for any BL 25 vertical chord that has not been repaired according to paragraph (i) or (j) of this AD.

   Cracks Found: Extending Below Water Line (WL) 159

   (i) If any crack is found on any BL 25 vertical chord during any inspection required by paragraph (g) or (h) of this AD, and the crack extends below WL 159: 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, the approval must specifically reference this AD.

   Cracks Found: Not Extending Below WL 159

   (j) If any crack is found in any BL 25 vertical chord during any inspection required by paragraph (g) or (h) of this AD, and the crack does not extend below WL 159: Before further flight, repair any damaged BL 25 vertical chord in accordance with the service bulletin.

   Repaired BL 25 Vertical Chords

   (k) Repair of any BL 25 vertical chord in accordance with paragraph (i) or (j) of this AD, as applicable, terminates the repetitive inspections required by paragraph (h) of this AD for the repaired vertical chord only. If both the left and right BL 25 vertical chords are repaired as required by paragraph (i) or (j) of this AD, as applicable, no more work is required by this AD.

   Alternative Methods of Compliance (AMOCs)

   (l)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

   (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 July 30, 2004. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 04-17986 Filed 8-5-04; 8:45 am]

   BILLING CODE 4910-13-P