04-25191. Airworthiness Directives; Boeing Model 767-200, -300, and -300F Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 767-200, -300, and -300F series airplanes. This AD requires reworking the surface of the ground stud brackets of the transformer rectifier unit (TRU) and the airplane structure mounting surface, and measuring the resistance from the bracket to the structure and the ground lug to the bracket using a bonding meter. This AD is prompted by a report of loss of all direct current (DC) power generation during a flight, due to inadequate electrical ground path between the ground bracket of the TRU and the structure. We are issuing this AD to prevent depletion of the main battery and consequent loss of all DC power, which could cause the loss of flight critical systems.

DATES:

Effective December 1, 2004.

The incorporation by reference of certain publications listed in the AD is approved by the Director of the Federal Register as of December 1, 2004.

We must receive comments on this AD by January 18, 2005.

ADDRESSES:

Use one of the following addresses to submit comments on this 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.
• Fax: [phone].
• 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.

For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. You can examine this information at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call [phone], or go to: http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

You can examine the contents of this AD docket on the Internet at http://dms.dot.gov, or in person 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.

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.

Examining the Dockets

You can examine the AD docket on the Internet at http://dms.dot.gov, or 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 [phone]) 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.

FOR FURTHER INFORMATION CONTACT:

Technical information: Louis Natsiopoulous, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

Plain language information: Marcia Walters, [e-mail].

SUPPLEMENTARY INFORMATION:

We have received a report of loss of DC power generation on a Boeing Model 767 airplane during flight. Investigation by Boeing revealed that the operator had incorporated Boeing Service Bulletin 767-24-0119, dated May 14, 1998, and/or Revision 1, dated December 16, 1999, without proper preparation of the bonding surface of the ground bracket and the airplane structure. The inadequate preparation caused the loss of an adequate electrical ground path between the bracket and frame used for the transformer rectifier units (TRU) and the main battery charger, which caused the subsequent loss of all DC power generation. When the operator inspected the rest of its Model 767 fleet, it found a number of brackets that were not properly grounded. This condition, if not corrected, could result in depletion of the main battery and consequent loss of all DC power, which could cause the loss of flight critical systems.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 767-24A0119, Revision 2, dated August 19, 2004. The service bulletin describes procedures for reworking the bonding surfaces of the ground stud brackets of the TRU and airplane structure, and measuring the resistance from the bracket to the structure and from the ground lug to bracket using a bonding meter. The reworking includes:

• Removing the ground stud bracket of the TRU;
• Cleaning the bracket mounting surface and airplane structure surface for a faying surface bond;
• Installing the ground bracket assembly of the TRU to the surface using bolts;
• Applying fillet sealant to the bracket;
• Applying alodine to the prepared surfaces;
• And applying primer on bare metal surface.

We have also reviewed Boeing Information Notice 767-24A0119 IN 01, dated October 21, 2004. This information notice provides more detailed illustrations than those shown in Figure 1, Details A and B, of Boeing Alert Service Bulletin 767-24A0119, Revision 2, dated August 19, 2004. The information notice clarifies the Figure 1, Step 10, procedure of the Accomplishment Instructions in the service bulletin.

FAA's Determination and Requirements of This AD

The unsafe condition described previously is likely to exist or develop on other airplanes of the same type design. Therefore, we are issuing this AD to prevent depletion of the main battery and consequent loss of all DC power, which could cause the loss of flight critical systems. This AD requires accomplishing the actions specified in the service information described previously, except as discussed below in “Clarification of Error in the Service Bulletin.”

Clarification of Error in the Service Bulletin

Boeing has informed us of an inadvertent error in the service bulletin. In Step 4, Sheet 3, of Figure 1 of the Accomplishment Instructions, the service bulletin only specifies to install a collar with part number (P/N) BACC30M6. However, a second collar with P/N BACC30BL6, which is listed in paragraph 2.C., “Parts Necessary For Each Airplane,” is also acceptable for installation. We have included paragraph (g) in this AD to allow the installation of P/N BACC30BL6 as an alternative method of compliance to the corresponding requirement of paragraph (f) of this AD (which references the service bulletin as the appropriate source of service information for accomplishing the required actions).

Interim Action

This is considered to be interim action. The manufacturer has advised that it currently is developing a modification (to add a redundant TRU grounding bracket on all 767 airplanes) that will address the unsafe condition addressed by this AD. Once this modification is developed, approved, and available, we may consider additional rulemaking.

FAA's Determination of the Effective Date

An unsafe condition exists that requires the immediate adoption of this AD; therefore, providing notice and opportunity for public comment before the AD is issued is impracticable, and good cause exists to make this AD effective in less than 30 days.

Comments Invited

This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2004-19569; Directorate Identifier 2004-NM-179-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the 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 AD. Using the search function of our docket 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 can review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.

We are reviewing the writing style we currently use in regulatory documents. 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 with you. You can get more information about plain language at http://www/​faa.gov/​language and http://www.plainlanguage.gov.

Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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 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 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
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

2004-23-14 Boeing: Amendment 39-13869. Docket No. FAA-2004-19569; Directorate Identifier 2004-NM-179-AD.

Effective Date

(a) This AD becomes effective December 1, 2004.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 767-200, -300, and -300F series airplanes, as listed in Boeing Alert Service Bulletin 767-24A0119, Revision 2, dated August 19, 2004, certificated in any category; on which the actions of Boeing Service Bulletin 767-24-0119, dated May 14, 1998, and/or Revision 1, dated December 16, 1999, have been done.

Unsafe Condition

(d) This AD was prompted by a report of loss of all direct current (DC) power generation during a flight. The FAA is issuing this AD to prevent depletion of the main battery and consequent loss of all DC power, which could cause the loss of flight critical systems.

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.

Rework and Measure Resistance

(f) Within 45 days after the effective date of this AD, rework the ground stud bracket of the transformer rectifier unit (TRU) and structure mounting surface, and measure the resistance from the bracket to the structure and the grounding lug to the bracket using a bonding meter, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 767-24A0119, Revision 2, dated August 19, 2004, as revised by Boeing Information Notice 767-24A0119 IN 01, dated October 21, 2004, except as provided by paragraph (g) of this AD.

(g) Step 4, Sheet 3 of Figure 1 in the Accomplishment Instructions of the service bulletin only specifies to install one collar with part number (P/N) BACC30M6. However, a collar with P/N BACC30BL6 (as listed in paragraph 2.C., “Parts Necessary For Each Airplane” of the service bulletin) may be used as an alternative method of compliance (AMOC).

AMOCs

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

Material Incorporated by Reference

(i) You must use Boeing Alert Service Bulletin 767-24A0119, Revision 2, dated August 19, 2004, as revised by Boeing Information Notice 767-24A0119 IN 01, dated October 21, 2004, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approves the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. You can review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call [phone], or go to http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Issued in Renton, Washington, on November 3, 2004.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.