Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SP, and 747SR Series Airplanes

[Federal Register Volume 69, Number 236 (Thursday, December 9, 2004)]
[Rules and Regulations]
[Pages 71349-71351]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-26793]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19811; Directorate Identifier 2004-NM-201-AD; 
Amendment 39-13893; AD 2004-25-05]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SP, and 747SR 
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 
certain Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-
200C, 747-200F, 747-300, 747SP, and 747SR series airplanes. This AD 
requires repetitive inspections to detect cracks and fractures of the 
strut front spar chord assembly at each strut location, and repair if 
necessary. This AD is prompted by a report of a fractured front spar 
chord assembly for strut No. 3, which resulted in the loss of the strut 
upper link load path. We are issuing this AD to prevent loss of the 
strut upper link load path and consequent fracture of the diagonal 
brace, which could result in in-flight separation of the strut and 
engine from the airplane.

DATES: Effective December 27, 2004.
    The incorporation by reference of certain publications listed in 
the AD is approved by the Director of the Federal Register as of 
December 27, 2004.
    We must receive comments on this AD by February 7, 2005.

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 9:00 
a.m. and 5:00 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact Boeing 
Commercial Airplanes, PO Box 3707, Seattle, Washington 98124-2207. You 
can examine this information 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.
    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-2004-19811; the directorate identifier for this docket is 
2004-NM-201-AD.

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: Ivan Li, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6437; fax (425) 917-6590. Plain language 
information: Marcia Walters, [email protected].

SUPPLEMENTARY INFORMATION: We have received a report indicating that 
the front spar chord assembly for strut No. 3 fractured on a Boeing 
Model 747-200B series airplane that had accumulated a total of 16,604 
flight cycles and 79,013 flight hours. The front spar chord assembly 
fractured 4.37 inches forward of the upper link attach lug. The 
manufacturer's analysis showed that the fitting fractured as the result 
of fatigue at a critical stress area. Fracture of the front spar chord 
assembly will result in the loss of the strut upper link load path. 
Loss of the upper link load path would result in the transfer of 
additional loads to the diagonal brace load path, which could result in 
fracture of the diagonal brace. This condition, if not corrected, could 
result in in-flight separation of the strut and engine from the 
airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin (ASB) 747-54A2224, 
dated September 30, 2004. The ASB describes procedures for 
accomplishing detailed and high frequency eddy current (HFEC) 
inspections of the strut front spar chord assembly for cracks and 
fractures at each strut location. The ASB also specifies, if any crack 
or fracture is found, to contact the manufacturer for additional 
instructions and repair. Accomplishing the actions specified in the 
service information is intended to adequately address the unsafe 
condition.

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 prevent loss of the strut upper link load path and 
consequent fracture

[[Page 71350]]

of the diagonal brace, which could result in in-flight separation of 
the strut and engine from the airplane. This AD requires accomplishing 
the actions specified in the service information described previously, 
except as discussed under ``Difference Between the AD and the ASB.''

Difference Between the AD and the ASB

    The ASB specifies that you may contact the manufacturer for 
instructions on how to repair certain conditions, but this AD requires 
you to repair those conditions 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.

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-2004-19811; 
Directorate Identifier 2004-NM-201-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.
    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):

2004-25-05 Boeing: Amendment 39-13893. Docket No. FAA-2004-19811; 
Directorate Identifier 2004-NM-201-AD.

Effective Date

    (a) This AD becomes effective December 27, 2004.

Applicability

    (b) This AD applies to Boeing 747-100, 747-100B, 747-100B SUD, 
747-200B, 747-200C, 747-200F, 747-300, 747SP, and 747SR series 
airplanes; as listed in Boeing Alert Service Bulletin (ASB) 747-
54A2224, dated September 30, 2004; certificated in any category.

Unsafe Condition

    (c) This AD was prompted by a report of a fractured front spar 
chord assembly for strut No. 3, which resulted in the loss of the 
strut upper link load path. The FAA is issuing this AD to prevent 
loss of the strut upper link load path and consequent fracture of 
the diagonal brace, which could result in in-flight separation of 
the strut and engine.

Compliance

    (d) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Detailed and High Frequency Eddy Current (HFEC) Inspections

    (e) Within 90 days after the effective date of this AD, perform 
detailed and HFEC inspections to detect any cracks or fractures of 
the front spar chord assembly for struts Number 1 through 4 
inclusive, in accordance with Boeing ASB 747-54A2224, dated 
September 30, 2004.
    (f) Accomplishment of the detailed and HFEC inspections in 
accordance with Boeing 747 Fleet Team Digest 747-FTD-54-04002, dated 
April 15, 2004, May 4, 2004, June 1, 2004, July 12, 2004, or July 
28, 2004; or Boeing Message 1-C6ELC (Service Request ID No.: 
218724992), dated April 14, 2004; before the effective date of this 
AD, is considered acceptable for compliance with the requirements of 
paragraph (e) of this AD.

Repetitive Inspections

    (g) For airplanes on which no crack or fracture is detected: At 
the times specified in Table 1--Repetitive Intervals of this AD, 
perform the detailed and HFEC inspections required by paragraph (e) 
of this AD at the intervals specified in Table 1.

                     Table 1.--Repetitive Intervals
------------------------------------------------------------------------
 For Airplanes identified in Boeing ASB
 747-54A2224, dated September 30, 2004,    At intervals not to exceed--
                  as--
------------------------------------------------------------------------
Group 1................................  1,000 flight cycles or 18
                                          months, whichever occurs
                                          first.
Group 2 and Group 3....................  1,200 flight cycles or 18
                                          months, whichever occurs
                                          first.
Group 4 and Group 6....................  1,500 flight cycles or 18
                                          months, whichever occurs
                                          first.
Group 5................................  2,000 flight cycles or 18
                                          months, whichever occurs
                                          first.
------------------------------------------------------------------------


[[Page 71351]]

Corrective Action

    (h) If any crack or fracture is found during any inspection 
required by this AD, and the bulletin specifies contacting Boeing 
for appropriate action: Before further flight, repair the crack or 
fracture according to a method approved by the Manager, Seattle 
Aircraft Certification Office (ACO), FAA; or per 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 those findings. For 
a repair method to be approved, the approval must specifically 
reference this AD.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Seattle 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) 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 Alert Service Bulletin 747-54A2224, 
dated September 30, 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, PO 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.

    Issued in Renton, Washington, on November 30, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-26793 Filed 12-8-04; 8:45 am]
BILLING CODE 4910-13-P

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