[Federal Register Volume 69, Number 214 (Friday, November 5, 2004)]
[Proposed Rules]
[Pages 64539-64541]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-24719]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19531; Directorate Identifier 2004-NM-45-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-300, -400, and -500 
Series Airplanes

AGENCY: Federal Aviation Administration (FAA), 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 all Boeing Model 737-300, -400, and -500 
series airplanes. The existing AD currently requires repetitive 
inspections of certain connectors located in the main wheel well to 
detect discrepancies, and corrective action if necessary. This proposed 
AD would instead mandate a modification. This proposed AD is prompted 
by the development of a modification intended to address the unsafe 
condition. We are proposing this AD to prevent discrepancies of certain 
connectors located in the main wheel well. Those discrepancies could 
result in electrical arcing of the connectors, uncommanded closure of 
the engine fuel shut-off valves, and consequent in-flight loss of 
thrust or engine shutdown from lack of fuel.

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.
     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: (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.

FOR FURTHER INFORMATION CONTACT:
    Technical information: Stephen Oshiro, Aerospace Engineer, Systems 
and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 917-6480; fax (425) 917-6590.
    Plain language information: Marcia Walters, [email protected].

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

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2004-19531; 
Directorate Identifier 2004-NM-45-AD'' at the beginning 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 received 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.

[[Page 64540]]

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 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 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

    On July 2, 2001, the FAA issued AD 2001-14-06, amendment 39-12316 
(66 FR 36445, July 12, 2001), for all Boeing Model 737-300, -400, and -
500 series airplanes. That AD requires repetitive inspections of 
certain connectors located in the main wheel well to detect 
discrepancies, and corrective action if necessary. That AD was prompted 
by reports indicating engine shutdown during flight due to uncommanded 
movement of the engine fuel shutoff valve. We issued that AD to detect 
and correct discrepancies of certain connectors located in the main 
wheel well, which could result in electrical arcing of the connectors, 
uncommanded closure of the engine fuel shut-off valves, and consequent 
in-flight loss of thrust or engine shutdown from lack of fuel.

Actions Since Existing AD Was Issued

    Since we issued AD 2001-14-06, the manufacturer has developed a 
modification intended to address the unsafe condition. The modification 
was developed after operators of Model 737 series airplanes reported 
additional incidents of short circuits between the electrical contacts 
in the connectors located in the main wheel well. One incident involved 
turning the airplane around and returning to the airport due to smoke 
in the cockpit. The smoke emission was from the P5-2 fuel system module 
located in the overhead panel, and was caused by a short circuit. These 
operators had previously complied with the actions required by the 
existing AD. This has led us to determine that the currently required 
actions do not address the unsafe condition. A short between the 
outboard landing light and the engine fuel shut-off valve circuits 
could result in uncommanded closure of the engine fuel shut-off valves, 
and consequent in-flight loss of thrust or engine shutdown from lack of 
fuel.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 737-28-
1196, Revision 3, dated April 1, 2004. The service bulletin describes 
procedures for modification of the two electrical connectors located in 
the main wheel well. The modification includes, but is not limited to: 
Performing a close visual inspection of the plug and receptacle 
connectors for discrepancies (contamination, corrosion, heat 
discoloration, arcing, and other damage), and replacing with new 
connectors if any discrepancy is found.
    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 products 
of this same type design. Therefore, we are proposing this AD, which 
would supersede AD 2001-14-06. This proposed AD would mandate a 
modification of the two electrical connectors in the main wheel well. 
This proposed AD would require you to use the service information 
described previously to perform these actions, except as discussed 
under ``Difference Between the Proposed AD and Service Bulletin.''

Differences Between the Proposed AD and Service Bulletin

    The 18-month compliance time required by this proposed AD is the 
result of a technical discussion between the FAA and the airplane 
manufacturer. Boeing Special Attention Service Bulletin 737-28-1196, 
Revision 3, dated April 1, 2004, erroneously specifies a 6-month 
compliance time. In light of this error, the compliance times of the 
existing AD, and technical discussions with the manufacturer, we are 
proposing less restrictive compliance requirements in this AD. For 
airplanes that have been inspected in accordance with AD 2001-14-16, 
the modification would be required within 18 months after the last 
inspection per AD 2001-14-16, or within 6 months after the effective 
date of this AD, whichever is later. For airplanes that have not been 
inspected in accordance with AD 2001-14-16 as of the effective date of 
this AD, the modification would be required within 12 months after the 
effective date of this AD. These compliance times represent an 
appropriate interval of time for affected airplanes to continue to 
operate without compromising safety.
    The service bulletin refers only to a ``close visual inspection'' 
for discrepancies of the plug and receptacle connectors. We have 
determined that the procedures in the service bulletin should be 
described as a ``general visual inspection.''

Costs of Compliance

    There are about 1,974 Model 737-300, -400, and -500 airplanes 
worldwide of the affected design. This proposed AD would affect about 
755 airplanes of U.S. registry.
    The new proposed modification (including the operational tests) 
would take about 9 work hours per airplane, at an average labor rate of 
$65 per work hour. Required parts cost would be minimal. Based on these 
figures, the estimated cost of the modification specified in this 
proposed AD for U.S. operators is $441,675, or $585 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.

[[Page 64541]]

    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 removing 39-12316 (66 FR 36445, 
July 12, 2001) and adding the following new airworthiness directive 
(AD):

Boeing: Docket No. FAA-2004-19531; Directorate Identifier 2004-NM-
45-AD.

Comments Due Date

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

Affected ADs

    (b) This AD supersedes AD 2001-14-06, amendment 39-12316.

Applicability

    (c) This AD applies to all Boeing Model 737-300, -400, and -500 
series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD was prompted by the development of a modification 
intended to address the unsafe condition. We are issuing this AD to 
detect and correct discrepancies of certain connectors located in 
the main wheel well. Those discrepancies could result in electrical 
arcing of the connectors, uncommanded closure of the engine fuel 
shut-off valves, and consequent in-flight loss of thrust or engine 
shutdown from lack of fuel.

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.

Modification

    (f) At the applicable time specified in paragraph (f)(1) or 
(f)(2) of this AD: Modify the electrical connectors located in the 
main wheel well by doing all the actions in accordance with the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 737-28-1196, Revision 3, dated April 1, 2004. Any 
corrective action must be done before further flight in accordance 
with the service bulletin.
    (1) For airplanes on which no inspection required by AD 2001-14-
06 has been done as of the effective date of this AD: Accomplish the 
modification within 12 months after the effective date of this AD.
    (2) For airplanes on which any inspection required by AD 2001-
14-06 has been done as of the effective date of this AD: Accomplish 
the modification at the later of the times specified in paragraph 
(f)(2)(i) or (f)(2)(ii) of this AD.
    (i) Within 18 months after accomplishing the last inspection.
    (ii) Within 6 months after the effective date of this AD.

Modifications Done Using Previous Issues of the Service Bulletin

    (g) Modifications done before the effective date of this AD in 
accordance with Boeing Special Attention Service Bulletin 737-28-
1196, dated December 5, 2002; Revision 1, dated March 13, 2003; or 
Revision 2, dated August 21, 2003; are considered acceptable for 
compliance with paragraph (f) of this AD.

Alternative Methods of Compliance (AMOCs)

    (h)(1) 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.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD 2001-14-06, amendment 39-12316, are approved as 
AMOCs for this AD.

    Issued in Renton, Washington, on October 26, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-24719 Filed 11-4-04; 8:45 am]
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