[Federal Register Volume 69, Number 214 (Friday, November 5, 2004)]
[Proposed Rules]
[Pages 64513-64515]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-24728]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19540; Directorate Identifier 2004-NM-110-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Boeing Model 757 airplanes. This proposed AD would require 
inspections of certain wire bundles in the left and right engine-to-
wing aft fairings for discrepancies, and other specified and corrective 
actions. This proposed AD is prompted by a report indicating that a 
circuit breaker for the fuel shutoff valve tripped due to a wire that 
chafed against the structure in the flammable leakage zone of the aft 
fairing, causing a short circuit. We are proposing this AD to prevent 
chafing between the wire bundle and the structure of the aft fairing, 
which could result in electrical arcing and subsequent ignition of 
flammable vapors and possible uncontrollable fire.

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

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
    <bullet> DOT Docket Web site: Go to  http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, 
Washington, DC 20590.
    <bullet> By fax: (202) 493-2251.
    <bullet> 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 proposed AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
    You can 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: Technical information: Thomas Thorson, 
Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6508; fax (425) 917-6590.
    Plain language information: Marcia Walters, <a href="/cdn-cgi/l/email-protection#016c60736268602f76606d75647372416760602f666e77"><span class="__cf_email__" data-cfemail="5c313d2e3f353d722b3d3028392e2f1c3a3d3d723b332a">[email protected]</span></a>.

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

[[Page 64514]]

Docket Number'') as a cross-reference for searching purposes.

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2004-19540; 
Directorate Identifier 2004-NM-110-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 can review 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 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 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 (800) 647-
5227) is 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 indicating that a circuit breaker of the 
fuel shutoff valve tripped due to a wire that chafed against the 
structure in the flammable leakage zone of the aft fairing, causing a 
short circuit. This occurred on a Boeing Model 757-200 series airplane 
that had accumulated approximately 10,900 total flight hours and 6,225 
total flight cycles. Subsequent maintenance inspections of the 
remainder of the operator's fleet revealed 9 out of 13 airplanes had 
the same type of wire chafing. The causes of that chafing were missing 
or incorrectly installed wire sleeving, incorrect grommet installation, 
and incorrect wire clamp installation. The existing design allows 
contact between the wire bundle and the engine strut webs. Chafing 
between the wire bundle and the structure of the aft fairing could 
result in electrical arcing and subsequent ignition of flammable vapors 
and possible uncontrollable fire.
    The wire bundles of the fuel shutoff valves on Model 757-200PF, -
200CB, and -300 series airplanes are identical to those on the affected 
Model 757-200 series airplanes. Therefore, all of these models may be 
subject to the same unsafe condition.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletins 757-28A0073 (for 
Model 757-200, -200CB, and -200PF series airplanes) and 757-28A0074 
(For Model 757-300 series airplanes), both dated November 20, 2003. The 
service bulletins describe procedures for inspecting for discrepancies 
of the wire bundles (W5100 for the left engine strut; W5200 for the 
right engine strut) from power plant station (PP STA) 278 aft, to the 
rear spar of the wing in the left and right engine-to-wing aft 
fairings, and other specified and corrective actions. The discrepancies 
include chafing of the wire bundles, missing or chafed sleeves, and 
incorrect installation of the caterpillar grommet. The procedures for 
the other specified and corrective actions include:
    <bullet> Repairing any damage found, in addition to installing a 
new support bracket.
    <bullet> Inspecting for chafed or missing sleeves at PP STA 278, 
290, and 301, and adding a new wrap-on sleeve if the sleeve is chafed 
or missing.
    <bullet> Inspecting the PP STA 278 and 301 bulkheads to ensure 
correct installation of the caterpillar grommet, and cleaning the area 
and installing a new grommet if the grommet is missing or incorrectly 
installed; and
    <bullet> Re-routing the wire bundles.
    The service bulletins also describe procedures for a functional 
test of the engine fuel shutoff valves. 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 exist or develop on other airplanes 
of this same type design. Therefore, we are proposing this AD, which 
would require accomplishing the actions specified in the service 
information described previously.

Clarification of Inspection Terminology

    In this proposed AD, the ``inspections'' of the wire bundles, as 
specified in the Boeing service bulletins are referred to as ``detailed 
inspections.'' We have included the definition for a detailed 
inspection in a note in the proposed AD.

Costs of Compliance

    This proposed AD would affect about 613 airplanes worldwide and 335 
airplanes of U.S. registry. The proposed actions would take about 16 
work hours per airplane, at an average labor rate of $65 per work hour. 
Required parts would cost about $560 per airplane. Based on these 
figures, the estimated cost of the proposed AD for U.S. operators is 
$536,000, or $1,600 per airplane.

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.

[[Page 64515]]

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-2004-19540; Directorate Identifier 2004-NM-
110-AD.

Comments Due Date

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

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Model 757-200, -200PF, -200CB, and -300 
series airplanes; certificated in any category; as listed in Boeing 
Alert Service Bulletins 757-28A0073 and 757-28A0074, both dated 
November 20, 2003.

Unsafe Condition

    (d) This AD was prompted by a report indicating that a circuit 
breaker for the fuel shutoff valve tripped due to a wire that chafed 
against the structure in the flammable leakage zone of the aft 
fairing, causing a short circuit. We are issuing this AD to prevent 
chafing between the wire bundle and the structure of the aft 
fairing, which could result in electrical arcing and subsequent 
ignition of flammable vapors and possible uncontrollable fire.

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.

One-Time Inspections/Investigative and Corrective Actions

    (f) Within 60 months after the effective date of this AD: 
Accomplish the detailed inspections for discrepancies of the wire 
bundles in the left and right engine-to-wing aft fairings, and other 
specified and corrective actions, as applicable, by doing all the 
actions in the Accomplishment Instructions of Boeing Alert Service 
Bulletin 757-28A0073 (for Model 757-200, -200CB, and -200PF series 
airplanes) or 757-28A0074 (for Model 757-300 series airplanes), both 
dated November 20, 2003; as applicable. Any corrective actions must 
be done before further flight and in accordance with the applicable 
service bulletin.

    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.''

Alternative Methods of Compliance (AMOCs)

    (g) 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.

    Issued in Renton, Washington, on October 27, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-24728 Filed 11-4-04; 8:45 am]
BILLING CODE 4910-13-P


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