[Federal Register Volume 69, Number 187 (Tuesday, September 28, 2004)]
[Proposed Rules]
[Pages 57884-57886]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-21648]



[[Page 57884]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19175; Directorate Identifier 2003-NM-246-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100B SUD, -200B, -300, 
-400, and -400D 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 747-100B SUD, -200B, -300, -400, and -400D 
series airplanes. This proposed AD would require repetitive inspections 
for cracking in fuselage stringers 8L, 8R, 10L, and 10R at body 
stations 460, 480, and 500 frame locations; and repair if necessary. 
This proposed AD is prompted by findings of cracking in fuselage 
stringers 8L, 8R, 10L, and 10R at body stations 460, 480, and 500 frame 
locations. We are proposing this AD to detect and correct fatigue 
cracking in certain fuselage stringers which, if left undetected, could 
result in fuselage skin cracking that reduces the structural integrity 
of the skin panel, and consequent rapid depressurization of the 
airplane.

DATES: We must receive comments on this proposed AD by November 12, 
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.
     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.
    You can get the service information identified in this proposed AD 
from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 
98124-2207.
    You may examine the AD docket, which contains the proposed AD, 
comments received, and any final disposition, on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Nick Kusz, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6432; fax (425) 917-6590.

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-2004-19175; 
Directorate Identifier 2003-NM-246-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 may review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may 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 may examine the AD docket 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 reports of cracking at fuselage stringers 8L, 8R, 
10L, and 10R at body station 460, 480, and 500 frame locations. These 
stringers are above and below the upper deck windows. The cracking was 
found on certain Boeing Model 747-100B SUD, -200B, -300, -400, and -
400D series airplanes having stretched upper decks. Investigation 
revealed that the cracking was caused by fatigue. The affected 
airplanes had between 29,873 and 90,333 total flight hours and between 
9,691 and 25,513 total flight cycles. If the fatigue cracking at the 
specified locations is not detected and corrected, the cracking could 
grow to include the fuselage skin along the window belt of the upper 
deck. Such cracking of the fuselage skin could result in reduced 
structural integrity of the skin panel, and consequent rapid 
depressurization of the airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-53A2484, dated 
June 26, 2003. The service bulletin describes procedures for doing 
repetitive detailed visual inspections of fuselage stringers 8L, 8R, 
10L, and 10R at body station 460, 480, and 500 frame locations and 
repairing areas with cracking. The repair procedures include installing 
new frame clips and new, additional stringer splices and doublers. For 
cracking that exceeds the specified limitations, the service bulletin 
specifies to install new sections of stringer in accordance with the 
747 Structural Repair Manual along with incorporation of repair parts 
from the service bulletin. The service bulletin also describes an 
optional modification, which eliminates the need for the repetitive 
inspections. The optional modification includes procedures for 
installing new frame

[[Page 57885]]

clips and new doublers; and repairing, as applicable. Accomplishing the 
actions specified in the service bulletin 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 repetitive inspections for fatigue cracking in fuselage 
stringers 8L, 8R, 10L, and 10R at body station 460, 480, and 500 frame 
locations; and repair if necessary. The proposed AD also would provide 
an optional terminating action for the repetitive inspections. The 
proposed AD would require you to use the service information described 
previously to perform these actions, except as discussed under 
``Differences Between the Proposed AD and Service Information.''

Differences Between the Proposed AD and Service Information

    The manufacturer reanalyzed the service problem and has advised the 
FAA that the reanalysis has resulted in threshold and repetitive 
inspection intervals different from the service bulletin. This resulted 
in simplified initial thresholds and an increased number of flight 
cycles between repetitive inspections. This difference has been 
coordinated with the manufacturer.

Clarification of Inspection Terminology

    In this proposed AD, the ``detailed visual inspection'' specified 
in the Boeing service bulletin is referred to as a ``detailed 
inspection.'' We have included the definition for a ``detailed 
inspection'' in a note in this proposed AD.

Costs of Compliance

    This proposed AD would affect about 243 Boeing Model 747-100B SUD, 
-200B, -300, -400, and -400D series airplanes worldwide. The following 
table provides the estimated costs for U.S. operators to comply with 
this proposed AD.

                                                                     Estimated Costs
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                                                                                                                        Number  of U.S.-
                      Action                          Work  hours     Average labor        Parts           Cost per         registered      Fleet cost
                                                                      rate  per hour                       airplane        airplanes
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Inspection........................................               3              $65             None             $195               69          $13,455
--------------------------------------------------------------------------------------------------------------------------------------------------------

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-2004-19175; Directorate Identifier 2003-NM-
246-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by November 12, 2004.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to certain Boeing Model 747-100B SUD, -200B, 
-300, -400, and -400D series airplanes; certificated in any 
category; as listed in Boeing Alert Service Bulletin 747-53A2484, 
dated June 26, 2003.

Unsafe Condition

    (d) This AD was prompted by findings of cracking in fuselage 
stringers 8L, 8R, 10L, and 10R at body station 460, 480, and 500 
frame locations. We are proposing this AD to detect and correct 
fatigue cracking in the specified fuselage stringers which, if left 
undetected, could result in fuselage skin cracking that reduces the 
structural integrity of the skin panel, and consequent rapid 
depressurization of the airplane.

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

    (f) Do a detailed inspection for cracking in fuselage stringers 
8L, 8R, 10L, and 10R at body station 460, 480, and 500 frame 
locations, in accordance with Part 1 of the Accomplishment 
Instructions in Boeing Alert Service Bulletin 747-53A2484, dated 
June 26, 2003. Do the inspections at the applicable time specified 
in paragraph (f)(1) or (f)(2) of this AD. Repeat the inspection 
thereafter at intervals not to exceed 3,000 flight cycles until the 
requirements of paragraph (h) of this AD are accomplished.
    (1) For airplanes with 19,000 total flight cycles or less as of 
the effective date of this AD: Prior to the accumulation of 8,000 
total flight cycles or within 2,000 flight cycles after the 
effective date of this AD, whichever is later, not to exceed 20,000 
total flight cycles.
    (2) For airplanes with more than 19,000 total flight cycles as 
of the effective date of this AD: Within 1,000 flight cycles after 
the effective date of this AD.

    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.''


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Repair

    (g) If any cracking is found during any inspection required by 
paragraph (f) of this AD: Before further flight, repair the affected 
stringer in accordance with Part 2 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2484, dated 
June 26, 2003. Repair terminates the repetitive inspections required 
by paragraph (f) of this AD for only the repaired stringer/frame 
location.

Optional Terminating Action

    (h) Installing new frame clips and new doublers; and repairing 
as applicable; in accordance with Part 3 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2484, dated 
June 26, 2003, terminates the repetitive inspections required by 
this AD.

Alternative Methods of Compliance (AMOCs)

    (i) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19.

    Issued in Renton, Washington, on September 20, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-21648 Filed 9-27-04; 8:45 am]
BILLING CODE 4910-13-P