Federal Aviation Administration (FAA), Department of Transportation (DOT).
Notice of proposed rulemaking (NPRM).
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.
We must receive comments on this proposed AD by May 16, 2005.
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.Start Further Info
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.End Further Info End Preamble Start Supplemental Information
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://Start Printed Page 16446dms.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.
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.
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.Start List of Subjects
List of Subjects in 14 CFR Part 39End List of Subjects
The Proposed Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. The FAA amends § 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.
(c) This AD applies to Boeing Model 737-200, -300, and -400 series airplanes, certificated in any category, equipped with auxiliary fuel tanks.
(d) This AD was prompted by reports of chafing of the direct-current-powered float switch wiring insulation in the center fuel Start Printed Page 16447tank. 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.
(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.
(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.
(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.
Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 05-6347 Filed 3-30-05; 8:45 am]
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