[Federal Register Volume 70, Number 61 (Thursday, March 31, 2005)]
[Proposed Rules]
[Pages 16445-16447]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-6347]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20731; Directorate Identifier 2004-NM-260-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-200, -300, and -400 
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 adopt a new airworthiness directive (AD) 
for certain Boeing Model 737-200, -300, and -400 series airplanes. This 
proposed AD would require replacing the existing fueling float switch 
in the auxiliary fuel tank with a new, improved fueling float switch, 
installing a new liner system inside the float switch conduit, and 
performing related investigative and other specified actions. This 
proposed AD is prompted by reports of chafing of the direct-current-
powered float switch wiring insulation in the center fuel tank. We are 
proposing this AD to prevent contamination of the fueling float switch 
of the auxiliary fuel tank by moisture or fuel, and chafing of the 
float switch wiring against the float switch conduit in the fuel tank, 
which could present an ignition source inside the fuel tank that could 
cause a fire or explosion.

DATES: We must receive comments on this proposed AD by May 16, 2005.

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.
    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 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. This docket 
number is FAA-2005-20731; the directorate identifier for this docket is 
2004-NM-260-AD.

FOR FURTHER INFORMATION CONTACT: Sherry Vevea, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 917-6514; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

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-2005-20731; 
Directorate Identifier 2004-NM-260-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://

[[Page 16446]]

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 website, 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.

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 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 previously issued AD 2004-15-04, amendment 39-13738 (69 FR 
44580, July 27, 2004), for certain Boeing Model 737-200, -200C, -300, -
400, and -500 series airplanes. That AD requires, among other actions, 
replacing the fueling float switches in the center and wing fuel tanks 
with new, improved parts; installing a conduit liner system in the 
center fuel tank; and replacing conduit assemblies in the wing fuel 
tanks with new parts. That AD was prompted by several reports of 
chafing of the direct-current-powered float switch wiring insulation in 
the center fuel tank.
    We state in AD 2004-15-04 that we may consider additional 
rulemaking to require actions similar to those required by AD 2004-15-
04 be accomplished on the auxiliary fuel tanks on Model 737 series 
airplanes. We have now determined that additional rulemaking is 
necessary, and this proposed AD follows from that determination.

Relevant Service Information

    We have reviewed Boeing Service Bulletin 737-28A1192, Revision 1, 
dated August 21, 2003. The service bulletin describes procedures for 
replacing the existing fueling float switch in the auxiliary fuel tank 
with a new, improved fueling float switch, installing a new liner 
system inside the float switch conduit, and performing related 
investigative and other specified actions. The other specified actions 
include making wiring changes associated with installing the new, 
improved float switch. The related investigative actions consist of 
measuring resistance between the terminal of the bonding jumper and the 
float switch lug, the terminal of the bonding jumper and the conduit, 
and the fuel pump assembly and the conduit; testing the conduit for 
leakage; and testing to make sure that the float switch operates 
properly and that there is no fuel leakage. 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.

Costs of Compliance

    This proposed AD would affect about 103 airplanes worldwide and 44 
airplanes of U.S. registry. The proposed actions would take about 38 
work hours per airplane, at an average labor rate of $65 per work hour. 
Required parts would cost about $1,634 per airplane. Based on these 
figures, the estimated cost of the proposed AD for U.S. operators is 
$180,576, or $4,104 per airplane.

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, 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. 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-2005-20731; Directorate Identifier 2004-NM-
260-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by May 16, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-200, -300, and -400 
series airplanes, certificated in any category, equipped with 
auxiliary fuel tanks.

Unsafe Condition

    (d) This AD was prompted by reports of chafing of the direct-
current-powered float switch wiring insulation in the center fuel

[[Page 16447]]

tank. We are issuing this AD to prevent contamination of the fueling 
float switch of the auxiliary fuel tank by moisture or fuel, and 
chafing of the float switch wiring against the float switch conduit 
in the fuel tank, which could present an ignition source inside the 
fuel tank that could cause a fire or explosion.

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.

Replacement

    (f) Within 24 months after the effective date of this AD: 
Replace the existing fueling float switch in the auxiliary fuel tank 
with a new, improved fueling float switch, install a new liner 
system inside the float switch conduit, and perform related 
investigative and other specified actions, by doing all of the 
actions in accordance with the Accomplishment Instructions of Boeing 
Service Bulletin 737-28A1192, Revision 1, dated August 21, 2003.

Parts Installation

    (g) As of the effective date of this AD, no person may install a 
fueling float switch having part number 8300-146 on the auxiliary 
fuel tank of any airplane.

Actions Accomplished Previously

    (h) Replacements and conduit liner system installations 
accomplished before the effective date of this AD in accordance with 
Boeing Alert Service Bulletin 737-28A1192, dated March 27, 2003, are 
acceptable for compliance with the requirements of this AD.

Alternative Methods of Compliance (AMOCs)

    (i) 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.

    Issued in Renton, Washington, on March 21, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-6347 Filed 3-30-05; 8:45 am]
BILLING CODE 4910-13-P