
[Federal Register: November 19, 2007 (Volume 72, Number 222)]
[Proposed Rules]               
[Page 64964-64966]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19no07-18]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0203; Directorate Identifier 2007-NM-105-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 767-200, -300, -300F, and 
-400ER Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) that applies to certain Boeing Model 767-200, -300, and 
-300F series airplanes. The existing AD currently requires reworking 
the surface of the ground stud bracket of the left and right 
transformer rectifier units (TRUs) and the airplane structure mounting 
surface, and measuring the resistance from the bracket to the structure 
and the ground lugs to the bracket using a bonding meter. This proposed 
AD would revise the applicability of the existing AD to include 
additional airplanes and would also require, among other actions, 
installation of a new ground stud bracket using faying surface bonding. 
This proposed AD results from 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 TRUs/main battery charger 
(MBC) and the structure. We are proposing this AD to prevent depletion 
of the main battery while in flight, resulting from the loss of both 
TRUs and the MBC, and consequent loss of all DC power, which could 
impact the safe flight and landing of the airplane due to the loss of 
function or malfunction of essential/critical systems and displays in 
the cockpit.

DATES: We must receive comments on this proposed AD by January 3, 2008.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.

[[Page 64965]]

     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, 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.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (telephone 800-647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

FOR FURTHER INFORMATION CONTACT: Louis Natsiopoulous, Aerospace 
Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6478; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSE section. Include ``Docket No. FAA-2007-0203; 
Directorate Identifier 2007-NM-105-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    On November 3, 2004, we issued AD 2004-23-14, amendment 39-13869 
(69 FR 67043, November 16, 2004), for certain Boeing Model 767-200, -
300, and -300F series airplanes. That AD requires reworking the surface 
of the ground stud bracket of the left and right transformer rectifier 
units (TRUs) and the airplane structure mounting surface, and measuring 
the resistance from the bracket to the structure and the ground lugs to 
the bracket using a bonding meter. That AD resulted from 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 
TRUs and the structure. We issued that AD to prevent depletion of the 
main battery and consequent loss of all DC power, which could cause the 
loss of flight critical systems.

Actions Since Existing AD Was Issued

    The preamble to AD 2004-23-14 explains that we consider the 
requirements ``interim action'' and were considering further rulemaking 
to add a redundant TRU ground bracket on all 767 airplanes. We now have 
determined that further rulemaking is indeed necessary, and this 
proposed AD follows from that determination.
    In addition, Boeing has informed us that additional airplanes are 
subject to the identified unsafe condition (i.e., depletion of the main 
battery while in flight, resulting from the loss of both TRUs and the 
MBC, and consequent loss of all DC power, which could impact the safe 
flight and landing of the airplane due to the loss of function or 
malfunction of essential/critical systems and displays in the cockpit).

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 767-24A0162, dated 
May 30, 2006. The service information describes the following major 
procedures, depending on the airplane configuration:
     Reworking the existing ground stud bracket of the TRUs/MBC 
and structure mounting surface.
     Measuring the resistance from that bracket to the 
structure and from the ground lugs to that bracket using a bonding 
meter.
     Installing a new ground stud bracket using faying surface 
bonding.

Accomplishing the actions specified in the service information is 
intended to 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 develop on other airplanes of the 
same type design. For this reason, we are proposing this AD, which 
would supersede AD 2004-23-14 and would retain the requirements of the 
existing AD. This proposed AD also would require accomplishing the 
applicable actions specified in service information described 
previously. In addition, this proposed AD would expand the 
applicability of the existing AD to include additional airplanes.

Costs of Compliance

    There are about 932 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                                     Estimated Costs
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                                                     Average                                           Number of  U.S.-
             Action                 Work hours      labor rate     Parts        Cost per  airplane        registered                Fleet cost
                                                     per hour                                              airplanes
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Rework and Measurement           1...............          $80           $4  $84.....................               262  $22,008.
 (required by AD 2004-23-14).
New proposed actions...........  1 or 2 \1\......           80          208  $288 or $368 \1\........               412  $118,656 or $151,616 \1\.
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\1\ Depending on the airplane configuration.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII,

[[Page 64966]]

Part A, Subpart III, Section 44701, ``General requirements.'' Under 
that section, Congress charges the FAA with promoting safe flight of 
civil aircraft in air commerce by prescribing regulations for 
practices, methods, and procedures the Administrator finds necessary 
for safety in air commerce. This regulation is within the scope of that 
authority because it addresses an unsafe condition that is likely to 
exist or develop on products identified in this rulemaking action.

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 and placed it in the AD docket. 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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-13869 (69 FR 67043, November 16, 2004) and adding 
the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2007-0203; Directorate Identifier 2007-NM-
105-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by January 
3, 2008.

Affected ADs

    (b) This AD supersedes AD 2004-23-14.

Applicability

    (c) This AD applies to Boeing Model 767-200, -300, -300F, and -
400ER series airplanes, certificated in any category, as identified 
in Boeing Alert Service Bulletin 767-24A0162, dated May 30, 2006.

Unsafe Condition

    (d) This AD results from 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 left and right 
transformer rectifier unit (TRUs)/main battery charger (MBC) and the 
structure. We are issuing this AD to prevent depletion of the main 
battery while in flight, resulting from the loss of both TRUs and 
the MBC, and consequent loss of all DC power, which could impact the 
safe flight and landing of the airplane due to the loss of function 
or malfunction of essential/critical systems and displays in the 
cockpit.

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.

Requirements of AD 2004-23-14

Rework and Measure Resistance

    (f) For Model 767-200, -300, and -300F series airplanes, as 
listed in Boeing Alert Service Bulletin 767-24A0119, Revision 2, 
dated August 19, 2004; 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: Within 45 days after December 1, 
2004 (the effective date of AD 2004-23-14), rework the ground stud 
bracket of the TRUs 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).

New Actions Required by This AD

Rework, Installation, Measurement, as Applicable

    (h) For all airplanes: Within 36 months after the effective date 
of this AD, rework the existing ground stud bracket of the TRUs/MBC, 
measure the resistance, and install a new ground stud bracket of the 
TRUs by doing all the applicable actions specified in the 
Accomplishment Instructions of Boeing Alert Service Bulletin 767-
4A0162, dated May 30, 2006.

AMOCs

    (i)(1) The Manager, Seattle Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.

    Issued in Renton, Washington, on November 7, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-22543 Filed 11-16-07; 8:45 am]

BILLING CODE 4910-13-P
