[Federal Register Volume 69, Number 239 (Tuesday, December 14, 2004)]
[Proposed Rules]
[Pages 74465-74467]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-27329]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19810; Directorate Identifier 2004-NM-119-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-600, -700, and -800 
Series 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 737-600, -700, and -800 series airplanes. This 
proposed AD would require doing a general visual inspection for sealant 
at the interface of the upper spar fittings, strut side skins, and the 
fittings of the thrust reverser strut fairing on the engine struts; and 
applying an injection seal or silicone sponge rubber with fillet seal 
if necessary. This proposed AD is prompted by a report that an 
injection seal in the engine strut area may not have been properly 
completed or installed during production. We are proposing this AD to 
prevent flammable fluid (such as fuel or hydraulic fluid) from leaking 
onto a hot engine exhaust nozzle or into the engine core fire zone, and 
consequently cause an uncontrolled fire or explosion.

DATES: We must receive comments on this proposed AD by January 28, 
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.

FOR FURTHER INFORMATION CONTACT: Technical information: Doug Pegors, 
Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6504; 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

[[Page 74466]]

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 relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2004-19810; 
Directorate Identifier 2004-NM-119-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 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.
    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

    We have received a report indicating that the injection seal at the 
interface of the upper spar fittings, strut side skins, and thrust 
reverser strut fairing fittings may not have been completed during 
production on certain Boeing Model 737-600, -700, and -800 series 
airplanes. The affected area is in a flammable fluid leakage zone, 
which requires absolute sealing of all openings. This condition, if not 
corrected, could result in flammable fluid (such as fuel or hydraulic 
fluid) leaking onto a hot engine exhaust nozzle or into the engine core 
fire zone, and consequently cause an uncontrolled fire or explosion.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 737-54-
1040, dated November 14, 2002; and Revision 1, dated August 14, 2003. 
The service bulletins describe procedures for doing a general visual 
inspection for sealant at the interface of the upper spar fittings, 
strut side skins, and the fittings of the thrust reverser strut fairing 
on the engine struts; and applying an injection seal or silicone sponge 
rubber with fillet seal if necessary. 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 257 airplanes worldwide and 99 
airplanes of U.S. registry. The proposed inspection would take about 2 
work hours per airplane, at an average labor rate of $65 per work hour. 
Based on these figures, the estimated cost of the proposed AD for U.S. 
operators is $12,870, or $130 per airplane.

Authority for This Rulemaking

    The FAA's authority to issue rules regarding aviation safety is 
found in Title 49 of the United States Code. 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.
    This rulemaking is promulgated under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, the FAA is charged with promoting 
safety 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 
proposed AD.

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-2004-19810; Directorate Identifier 2004-NM-
119-AD.

[[Page 74467]]

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by January 28, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-600, -700, and -800 
series airplanes, as listed in Boeing Special Attention Service 
Bulletin 737-54-1040, Revision 1, dated August 14, 2003; 
certificated in any category.

Unsafe Condition

    (d) This AD was prompted by a report that an injection seal in 
the engine strut area may not have been properly completed or 
installed during production. We are issuing this AD to prevent 
flammable fluid (such as fuel or hydraulic fluid) leaking onto a hot 
engine exhaust nozzle or into the engine core fire zone, and 
consequently cause an uncontrolled 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.

Inspection and Corrective Action

    (f) Within 18 months or 3,500 flight cycles after the effective 
date of this AD, whichever occurs first: Do a general visual 
inspection for sealant at the interface of the upper spar fittings, 
strut side skins, and the fittings of the thrust reverser strut 
fairing on the engine struts, in accordance with the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 737-54-
1040, dated November 14, 2002; or Revision 1, dated August 14, 2003.
    (1) If the injection seal is found to properly seal the entire 
gap, no further action is required by this AD.
    (2) If the injection seal is not found to properly seal the 
entire gap or if the injection seal is found to be missing, before 
further flight, apply an injection seal or silicone sponge rubber 
with fillet seal in accordance with the Accomplishment Instructions 
of the service bulletin.

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 December 1, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-27329 Filed 12-13-04; 8:45 am]
BILLING CODE 4910-13-P