[Federal Register Volume 71, Number 31 (Wednesday, February 15, 2006)]
[Proposed Rules]
[Pages 7883-7887]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-2170]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-23921; Directorate Identifier 2005-NM-205-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (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 747 series airplanes. 
The existing AD currently requires repetitive inspections for cracking 
of the top and side panel webs and panel stiffeners of the nose wheel 
well (NWW), and corrective actions if necessary. This proposed AD would 
reduce the interval for certain repetitive inspections and remove a 
certain optional inspection. This proposed AD would also require 
replacing the NWW side and top panels with new panels. The replacement 
would terminate the repetitive inspections. This proposed AD results 
from the development of a new modification. We are proposing this AD to 
prevent fatigue cracks in the top and side panel webs and stiffeners of 
the NWW, which could compromise the structural integrity of the NWW and 
could lead to the rapid decompression of the airplane.

DATES: We must receive comments on this proposed AD by April 3, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to

[[Page 7884]]

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.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Nick Kusz, 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:

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 in the ADDRESSES section. Include the docket number ``Docket No. 
FAA-2006-23921; Directorate Identifier 2005-NM-205-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. Using the search function of 
that 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 may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or may 
can visit http://dms.dot.gov.

Examining the Docket

    You may 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 Docket Management System 
receives them.

Discussion

    On April 13, 2005, we issued AD 2005-09-02, amendment 39-14070 (70 
FR 29940, May 25, 2005), for all Boeing Model 747 series airplanes. 
That AD requires repetitive inspections for cracking of the top and 
side panel webs and panel stiffeners of the nose wheel well (NWW), and 
corrective actions if necessary. That AD resulted from a report of an 
in-flight decompression of a Model 747-100 series airplane that had 
accumulated 27,241 total flight cycles. We issued that AD to detect and 
correct fatigue cracks in the top and side panel webs and stiffeners of 
the NWW, which could compromise the structural integrity of the NWW and 
could lead to the rapid decompression of the airplane.

Actions Since Existing AD Was Issued

    In the preamble to AD 2005-09-02, we stated that we considered the 
requirements ``interim action'' and were considering further rulemaking 
to reduce certain repetitive inspection intervals. In addition, we 
explained that the manufacturer was developing a modification and that 
we would consider additional rulemaking once the modification was 
developed, approved, and available. We now have determined that further 
rulemaking is indeed necessary, and this proposed AD follows from that 
determination.

Relevant Service Information

    We have reviewed Boeing Service Bulletin 747-53A2562, Revision 1, 
dated July 28, 2005. The service bulletin describes procedures for 
replacing the NWW side and top panels with new panels. 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 develop on other airplanes of the 
same type design. For this reason, we are proposing this AD, which 
would supersede AD 2005-09-02 and would continue to require repetitive 
inspections for cracking of the top and side panel webs and panel 
stiffeners of the NWW, and corrective actions if necessary. This 
proposed AD would also reduce the interval for certain repetitive 
inspections and would require replacing the NWW side and top panels 
with new panels. The replacement would terminate the repetitive 
inspections. The replacement would be accomplished in accordance with 
the actions specified in the service information described previously, 
except as discussed under ``Differences Between the Proposed AD and 
Boeing Service Bulletin 747-53A2562.''

Differences Between the Proposed AD and Boeing Service Bulletin 747-
53A2562

    Boeing Service Bulletin 747-53A2562, Revision 1, dated July 28, 
2005, specifies an effectivity of Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-300, 747-400, 747-400D, 747SR, and 747SP series 
airplanes, line numbers 1 through 1307. The service bulletin notes that 
a future revision will add airplanes with a nose cargo door, and 
airplanes after line number 1307. This proposed AD is applicable to all 
Model 747 airplanes. This proposed AD would require that, for Model 747 
airplanes identified as Group 1 and 3 in the service bulletin (Model 
747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747-400, 747-400D, 
747SR, and 747SP series airplanes, line numbers 1 through 1307, except 
those airplanes modified to the Special Freighter configuration), the 
replacement of the NWW side and top panels must be done according to 
the service bulletin. For all Model 747 airplanes identified as Group 2 
in the service bulletin and airplanes not identified in the service 
bulletin, the replacement must be done according to a method approved 
by the FAA.

Explanation of Change to Applicability

    We have revised the applicability of the existing AD to identify 
model designations as published in the most recent type certificate 
data sheet for the affected models.

Explanation of Changes Made to Paragraph (f) of This Proposed AD

    We have reduced the repetitive inspection intervals for Area 3 from 
6,000 flight cycles to 1,500 flight cycles for airplanes on which the 
inspections have been done in accordance with Boeing Alert Service 
Bulletin (ASB) 747-53A2465, Revision 2, dated November 11, 2004 
(referenced as the appropriate source of service information for doing 
the inspection specified in paragraph (f)(2)(ii) of the

[[Page 7885]]

existing AD). In addition, we have removed the optional inspection 
specified in paragraph (f)(1)(ii) of the existing AD; however, we have 
given credit for airplanes on which the inspections have been done in 
accordance with Boeing Service Bulletin 747-53A2465, Revision 1, dated 
October 16, 2003, for the Area 3 inspections. (Revision 1 was 
referenced as the appropriate source of service information for doing 
the inspection specified in paragraph (f)(1)(ii) of the existing AD 
with a repetitive inspection interval of 1,000 flight cycles.)
    Since issuance of Boeing ASB 747-53A2465, Revision 2, Boeing has 
received additional reports of cracking and has done additional 
analysis to determine the flight-cycle interval. The 1,500 flight-cycle 
interval for Area 3 specified in the proposed AD matches the interval 
specified in Boeing ASB 747-53A2465, Revision 4, dated February 24, 
2005 (referenced as the appropriate source of service information for 
doing the new requirements of the existing AD). We have determined that 
the 1,500 flight-cycle interval will ensure an acceptable level of 
safety.
    We also removed paragraphs (f)(1)(i) and (f)(2)(i) of the existing 
AD because all operators will be doing the inspections of the top and 
sidewall panel webs specified in paragraph (g) of the existing AD. The 
inspections specified in paragraph (g) of the existing AD terminate the 
inspections of the top and side panel webs specified in paragraphs 
(f)(1)(i) and (f)(2)(i) of the existing AD. Therefore we do not need to 
restate paragraphs (f)(1)(i) and (f)(2)(i) in the proposed AD.

Explanation of Change Made to This Proposed AD

    We have simplified paragraph (l) of this proposed AD by referring 
to the ``Alternative Methods of Compliance (AMOCs)'' paragraph of this 
proposed AD for repair methods and we have revised the AMOCs paragraph 
in this proposed AD to clarify the delegation authority for Authorized 
Representatives for the Boeing Commercial Airplanes Delegation Option 
Authorization.

Clarification of AMOC Paragraph

    We have revised this action to clarify the appropriate procedure 
for notifying the principal inspector before using any approved AMOC on 
any airplane to which the AMOC applies.

Costs of Compliance

    There are about 1,127 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD. Work hours are 
estimated at an average labor rate of $65 per work hour.

                                                                     Estimated Costs
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                                                                                                 Number of U.S.-
               Action                  Work hours         Parts          Cost per  airplane        registered                   Fleet cost
                                                                                                    airplanes
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Area 1 and 3 inspections (required               79              $0  $5,135, per inspection                 255  $1,309,425, per inspection cycle.
 by AD 2005-09-02).                                                   cycle.
Area 2 inspections (required by AD             8-18               0  $520-$1,170, per                       255  Up to $298,350, per inspection cycle.
 2005-09-02).                                                         inspection cycle.
Replacement (new proposed action)..             800         115,765  $167,765..................             255  $42,780,075.
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Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. 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.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe 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 
rulemaking action.

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 and placed it in the AD docket. 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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-14070 (70 FR 29940, May 25, 2005) and adding the 
following new airworthiness directive (AD):

Boeing: Docket No. FAA-2006-23921; Directorate Identifier 2005-NM-
205-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by April 3, 
2006.

Affected ADs

    (b) This AD supersedes AD 2005-09-02.

[[Page 7886]]

Applicability

    (c) This AD applies to all Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 
747-400F, 747SR, and 747SP series airplanes, certificated in any 
category.

Unsafe Condition

    (d) This AD results from the development of a new modification. 
We are issuing this AD to prevent fatigue cracks in the top and side 
panel webs and stiffeners of the nose wheel well (NWW), which could 
compromise the structural integrity of the NWW and lead to the rapid 
decompression 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.

Restatement of Requirements of AD 2005-09-02 With New Repetitive 
Interval and Service Information

Initial and Repetitive Inspections of the Top and Side Panel 
Stiffeners

    (f) Prior to the accumulation of 16,000 total flight cycles, or 
within 1,000 flight cycles after January 27, 2005 (the effective 
date of AD 2004-25-23, amendment 39-13911), whichever is later, do 
internal detailed and surface high frequency eddy current (HFEC) 
inspections of the top and side panel stiffeners of the NWW 
(specified as Area 3 in the service bulletin) for cracks in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin (ASB) 747-53A2465, Revision 4, dated February 25, 
2005. Repeat the inspections thereafter at the compliance times 
specified in paragraph (f)(1) or (f)(2) of this AD, as applicable.
    (1) For airplanes on which an inspection has not been done 
before the effective date of this AD in accordance with any service 
bulletin listed in Table 1 of this AD: Within 1,500 flight cycles 
after doing the inspection specified in paragraph (f) of this AD, 
repeat the inspection. Repeat the inspection thereafter at intervals 
not to exceed 1,500 flight cycles.
    (2) For airplanes on which an inspection has been done before 
the effective date of this AD in accordance with any service 
bulletin listed in Table 1 of this AD: Within 6,000 flight cycles 
after doing the inspection specified in paragraph (f) of this AD or 
within 1,500 flight cycles after the effective date of this AD, 
whichever occurs first, repeat the inspection. Repeat the inspection 
thereafter at intervals not to exceed 1,500 flight cycles.

                                       Table 1.--Boeing Service Bulletins
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               Service bulletin                Revision level                         Date
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Boeing ASB 747-53A2465.......................           (\1\)  April 5, 2001.
Boeing Service Bulletin 747-53A2465..........               1  October 16, 2003.
Boeing ASB 747-53A2465.......................               2  November 11, 2004.
Boeing ASB 747-53A2465.......................               3  December 23, 2004.
Boeing ASB 747-53A2465.......................               4  February 25, 2005.
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\1\ Original.


    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as 
mirrors, magnifying lenses, etc., may be used. Surface cleaning and 
elaborate access procedures may be required.''

Initial Inspections of the Top and Sidewall Panel Webs

    (g) Do an external detailed inspection of the top and sidewall 
panel webs of the NWW (specified as Area 1 and Area 2 in the service 
bulletin) for cracks, in accordance with the Accomplishment 
Instructions of Boeing ASB 747-53A2465, Revision 4, dated February 
24, 2005, at the earlier of the times specified in paragraphs (g)(1) 
and (g)(2) of this AD.
    (1) At the later of the times specified in paragraph (g)(1)(i) 
and (g)(1)(ii) of this AD:
    (i) Before accumulating 20,000 total flight cycles.
    (ii) Within 100 flight cycles or 90 days after May 10, 2005 (the 
effective date of AD 2005-09-02), whichever occurs first.
    (2) At the later of the times specified in paragraphs (g)(2)(i) 
and (g)(2)(ii) of this AD:
    (i) Before accumulating 16,000 total flight cycles.
    (ii) Within 1,000 flight cycles after May 10, 2005.

Repetitive Inspections of the Top and Sidewall Panel Webs

    (h) Repeat the inspection required by paragraph (g) of this AD 
at the intervals specified in paragraphs (h)(1) and (h)(2) of this 
AD, as applicable.
    (1) For airplanes with fewer than 20,000 total flight cycles as 
of May 10, 2005, repeat at intervals not to exceed 1,000 flight 
cycles until the first inspection after the airplane reaches 20,000 
total flight cycles.
    (2) For airplanes with 20,000 total flight cycles or more, 
repeat at intervals not to exceed 500 flight cycles.

Ultrasonic Inspections (UT)

    (i) Do a UT inspection of the top and sidewall panel webs for 
cracks, in accordance with Boeing ASB 747-53A2465, Revision 4, dated 
February 24, 2005, at the later of the times specified in paragraphs 
(i)(1) and (i)(2) of this AD. Repeat the inspections thereafter at 
intervals not to exceed 500 flight cycles.
    (1) Prior to the accumulation of 20,000 total flight cycles.
    (2) Within 100 flight cycles or 90 days after May 10, 2005, 
whichever occurs first.

Additional Inspections and Corrective Actions

    (j) Except as specified in paragraph (l) of this AD, if any 
crack is found during any inspection required by this AD, prior to 
further flight, do any applicable additional detailed inspections of 
stiffeners and beams and make repairs, in accordance with the 
Accomplishment Instructions of Boeing ASB 747-53A2465, Revision 4, 
dated February 24, 2005.

Actions Accomplished Per Previous Issues of Service Bulletin

    (k) The actions specified in paragraphs (k)(1), (k)(2), and 
(k)(3) of this AD are acceptable for compliance with the 
corresponding action specified in the applicable paragraph.
    (1) Inspections and corrective actions accomplished before 
January 27, 2005, in accordance with Boeing ASB 747-53A2465, dated 
April 5, 2001, are considered acceptable for compliance with the 
corresponding inspections specified in paragraph (f) of this AD.
    (2) Inspections accomplished before the effective date of this 
AD, in accordance with Boeing Service Bulletin 747-53A2465, Revision 
1, dated October 16, 2003; Boeing ASB 747-53A2465, Revision 2, dated 
November 11, 2004; and Boeing ASB 747-53A2465, Revision 3, dated 
December 23, 2004; are considered acceptable for compliance with the 
corresponding inspections specified in paragraph (f) of this AD.

    Note 2: The detailed and surface HFEC inspections of the top and 
side panel stiffeners of the NWW specified in Boeing ASB 747-
53A2465, dated April 5, 2001; and Boeing Service Bulletin 747-
53A2465, Revision 1, dated October 16, 2003; are acceptable for 
compliance with the internal detailed and surface HFEC inspections 
specified in paragraph (f) of this AD.

    (3) Inspections and corrective actions accomplished before May 
10, 2005, in accordance with Boeing Service Bulletin 747-53A2465, 
Revision 1, dated October 16, 2003; Boeing ASB 747-53A2465, Revision 
2, dated November 11, 2004; and Boeing ASB 747-53A2465, Revision 3, 
dated December 23, 2004; are considered acceptable for compliance 
with the corresponding inspections specified in paragraphs (g) and 
(h) of this AD.

[[Page 7887]]

Certain Other Corrective Actions

    (l) Where Boeing ASB 747-53A2465 specifies contacting the 
manufacturer if certain cracking is found, this AD requires, before 
further flight, repairing the cracking using a method approved in 
accordance with the procedures specified in paragraph (p) of this 
AD.

No Reporting Requirement

    (m) Although Boeing ASB 747-53A2465 specifies that operators 
should report inspection results to the manufacturer, this AD does 
not require those inspection results to be reported.

New Requirements of This AD

Terminating Action

    (n) For Group 1 and 3 airplanes identified in Boeing Service 
Bulletin 747-53A2562, Revision 1, dated July 28, 2005: Before 
accumulating 22,000 total flight cycles or within 48 months after 
the effective date of this AD, whichever occurs later, replace the 
NWW side and top panels with new panels in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 747-53A2562, 
Revision 1, dated July 28, 2005. Doing the replacement terminates 
the requirements of this AD.
    (o) For Group 2 airplanes identified in Boeing Service Bulletin 
747-53A2562, Revision 1, dated July 28, 2005, and Model 747 
airplanes not identified in the service bulletin: Before 
accumulating 22,000 total flight cycles or within 48 months after 
the effective date of this AD, whichever occurs later, replace the 
NWW side and top panels using a method approved by the Manager, 
Seattle Aircraft Certification Office (ACO), FAA. Doing the 
replacement terminates the requirements of this AD.

Alternative Methods of Compliance (AMOCs)

    (p)(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) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who has been authorized 
by the Manager, Seattle ACO, to make those findings. For a repair 
method to be approved, the repair must meet the certification basis 
of the airplane.
    (4) AMOCs approved previously according to AD 2005-09-02, 
amendment 39-14070, are approved as AMOCs for the corresponding 
provisions of paragraphs (f) through (j) and (l) of this AD.
    (5) AMOCs approved previously according to AD 2004-25-23, 
amendment 39-13911, are approved as AMOCs for the corresponding 
provisions of paragraph (f) of this AD.

    Issued in Renton, Washington, on January 26, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E6-2170 Filed 2-14-06; 8:45 am]
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