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

[Federal Register Volume 69, Number 207 (Wednesday, October 27, 2004)]
[Rules and Regulations]
[Pages 62567-62569]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-23924]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19461; Directorate Identifier 2004-NM-169-AD; 
Amendment 39-13833; AD 2004-22-05]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Boeing Model 737-300, -400, and -500 series airplanes. This AD requires 
inspecting for discrepancies of the fuselage skin under the dorsal fin 
assembly, and repairing if necessary. This AD is prompted by a report 
of an 18-inch crack found in the fuselage skin area under the blade 
seals of the nose cap of the dorsal fin due to previous wear damage. We 
are issuing this AD to find and fix discrepancies of the fuselage skin, 
which could result in fatigue cracking due to cabin pressurization, and 
consequent rapid in-flight decompression of the airplane fuselage.

DATES: Effective November 12, 2004.
    The incorporation by reference of a certain publication listed in 
the AD is approved by the Director of the Federal Register as of 
November 12, 2004.
    We must receive comments on this AD by December 27, 2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this 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> 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 AD, contact Boeing 
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. 
You can examine this information at the National

[[Page 62568]]

Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call (202) 741-6030, or go to: 
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html html.
    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.

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.

Examining the Dockets

    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.

FOR FURTHER INFORMATION CONTACT:
    Technical information: Sue Lucier, Aerospace Engineer, Airframe 
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6438; 
fax (425) 917-6590.
    Plain language information: Marcia Walters, [email protected].

SUPPLEMENTARY INFORMATION:
    We have recently received a report indicating that wear of the 
fuselage skin was found between body stations 860 and 1006 on a Boeing 
Model 737-300 series airplane. Subsequently, an 18-inch crack developed 
in the area of the wear. Fuselage skin wear is attributed to the 
movement of the blade seals, which provide an aerodynamic seal between 
the dorsal fin fairing and the fuselage skin. Wear damage of the 
fuselage skin, if not found and fixed, could result in fatigue cracking 
due to cabin pressurization, and consequent rapid in-flight 
decompression of the airplane fuselage.

Relevant Service Information

    We have reviewed Boeing Message Number 1-QXO35, dated October 13, 
2004. The message describes procedures for repetitive detailed 
inspections of the fuselage skin under the dorsal fin assembly for 
discrepancies (i.e., wear or cracking), and contacting Boeing for 
repair instructions. The message also describes procedures for 
accomplishing a detailed inspection for discrepancies if any repair 
doubler is installed.
    We have also reviewed Boeing Service Bulletin 737-55-1057, Revision 
1, dated July 22, 1999; specified in the Boeing message as an 
additional source of service information for accomplishing the actions. 
Part I of the Accomplishment Instructions of the service bulletin 
describes procedures for inspecting for discrepancies of the fuselage 
skin under the dorsal fin assembly. The discrepancies include chafing, 
wear damage, and lack of abrasion-resistant coating.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other airplanes of the same type design. Therefore, we are 
issuing this AD to find and fix discrepancies of the fuselage skin, 
which could result in fatigue cracking due to cabin pressurization, and 
consequent rapid in-flight decompression of the airplane fuselage. This 
AD requires accomplishing the actions specified in Boeing Message 
Number 1-QXO35, described previously, except as discussed under 
``Difference Between the AD and Boeing Message Number 1-QXO35.''

Difference Between the AD and Boeing Message Number 1-QXO35

    The message specifies that operators may contact the manufacturer 
for repair instructions, but this AD requires you to repair cracking in 
one of the following ways:
    <bullet> Using a method that we approve; or
    <bullet> Using data that meet the type certification basis of the 
airplane, and that have been approved by a Boeing Company Designated 
Engineering Representative who has been authorized by the FAA to make 
those findings.
    Although the message recommends reporting any fuselage skin 
cracking found during the detailed inspections, this AD does not 
require that action.

FAA's Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD; therefore, providing notice and opportunity for public comment 
before the AD is issued is impracticable, and good cause exists to make 
this AD effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements that affect 
flight safety and was not preceded by notice and an opportunity for 
public comment; however, we invite you to submit any relevant written 
data, views, or arguments regarding this AD. Send your comments to an 
address listed under ADDRESSES. Include ``Docket No. FAA-2004-19461; 
Directorate Identifier 2004-NM-169-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the AD. We will consider 
all comments received by the closing date and may amend the 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 AD. 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 with you. You can get more information about plain 
language at http://www/faa.gov/language and http://www.plainlanguage.gov

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD will 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.

[[Page 62569]]

    For the reasons discussed above, I certify that the 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 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2004-22-05 Boeing: Amendment 39-13833. Docket No. FAA-2004-19461; 
Directorate Identifier 2004-NM-169-AD.

Effective Date

    (a) This AD becomes effective November 12, 2004.

Affected ADs

    (b) None.

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 a report of an 18-inch crack found 
in the fuselage skin area under the blade seals of the nose cap of 
the dorsal fin due to previous wear damage. We are issuing this AD 
to find and fix discrepancies of the fuselage skin, which could 
result in fatigue cracking due to cabin pressurization, and 
consequent rapid in-flight decompression of the airplane fuselage.

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.

Repetitive Detailed Inspections

    (f) For airplanes specified in either paragraph (f)(1), (f)(2), 
(f)(3), or (f)(4) of this AD: Accomplish a detailed inspection for 
discrepancies (wear or cracking) of the fuselage skin under the 
dorsal fin assembly by doing all the actions specified in Boeing 
Message Number 1-QXO35, dated October 13, 2004. Repeat the 
inspection thereafter at intervals not to exceed 9,000 flight 
cycles.

    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.''


    (1) For airplanes with line numbers 1001 through 2828 inclusive 
that have not been inspected as of the effective date of this AD, in 
accordance with Boeing Service Bulletin 737-55-1057, dated December 
12, 1996; or Revision 1, dated July 22, 1999: Inspect before the 
accumulation of 18,000 total flight cycles, or within 90 days after 
the effective date of this AD, whichever is later.
    (2) For airplanes with line numbers 2829 through 3132 inclusive 
that are not included in the effectivity of Boeing Service Bulletin 
737-55-1057, dated December 12, 1996; or Revision 1, dated July 22, 
1999: Inspect before the accumulation of 18,000 total flight cycles, 
or within 90 days after the effective date of this AD, whichever is 
later.
    (3) For airplanes with line numbers 1001 through 2828 inclusive 
that have been inspected, but not repaired or modified as of the 
effective date of this AD, in accordance with Boeing Service 
Bulletin 737-55-1057, dated December 12, 1996; or Revision 1, dated 
July 22, 1999: Inspect within 9,000 flight cycles after 
accomplishing the inspection, or within 90 days after the effective 
date of this AD, whichever is later.
    (4) For airplanes with line numbers 1001 through 2828 inclusive 
that have been inspected and repaired or modified as of the 
effective date of this AD, in accordance with Boeing Service 
Bulletin 737-55-1057, dated December 12, 1996; or Revision 1, dated 
July 22, 1999: Inspect within 18,000 flight cycles after 
accomplishing the repair or modification, or within 90 days after 
the effective date of this AD, whichever is later; and if a repair 
doubler is installed, before further flight, inspect the repair 
doubler for discrepancies (wear or cracking).

    Note 2: Boeing Message Number 1-QXO35, dated October 13, 2004, 
references Part I of Boeing Service Bulletin 737-55-1057, Revision 
1, dated July 22, 1999; as an additional source of service 
information for accomplishing the actions required by paragraph (f) 
of this AD.


Repair

    (g) If any discrepancy (wear or cracking) is found during any 
inspection required by this AD, before further flight, repair in 
accordance with a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA; or in accordance with data meeting 
the type certification basis of the airplane approved by a Boeing 
Company Designated Engineering Representative (DER) who has been 
authorized by the Manager, Seattle ACO, to make such findings. For a 
repair method to be approved, the approval must specifically refer 
to this AD.

    Note 3: No terminating action is currently available for the 
repetitive inspections required by this AD.

Reporting Not Required

    (h) Although Boeing Message Number 1-QXO35, dated October 13, 
2004, specifies to report any fuselage skin cracking found during 
the detailed inspections, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Seattle ACO, has the authority to approve 
AMOCs for this AD, if requested in accordance with the procedures 
found in 14 CFR 39.19.
    (2) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by a 
Boeing Company DER who has been authorized by the Manager, Seattle 
ACO, to make those findings. For a repair method to be approved, the 
approval must specifically refer to this AD.

Material Incorporated by Reference

    (j) You must use Boeing Message Number 1-QXO35, dated October 
13, 2004, to perform the actions that are required by this AD, 
unless the AD specifies otherwise. The Director of the Federal 
Register approves the incorporation by reference of this document in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the 
service information, contact Boeing Commercial Airplanes, P.O. Box 
3707, Seattle, Washington 98124-2207. You can review copies at the 
Docket Management Facility, U.S. Department of Transportation, 400 
Seventh Street SW, room PL-401, Nassif Building, Washington, DC; or 
at the National Archives and Records Administration (NARA). For 
information on the availability of this material at NARA, call (202) 
741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html html.

    Issued in Renton, Washington, on October 18, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-23924 Filed 10-26-04; 8:45 am]
BILLING CODE 4910-13-P

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