AD 2005-09-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | 747 | Airworthiness Directives; Boeing Model 747 Series Airplanes |
Unsafe Condition
Fatigue cracks in the top and side panel webs and stiffeners of the nose wheel well (NWW) could compromise the structural integrity of the NWW and lead to rapid decompression of the airplane.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the top and side panel webs and stiffeners of the NWW for cracking, expand the inspection area, perform a new 'secondary' inspection if certain cracking is found, and reduce repetitive inspection intervals. Replace cracked stiffeners with new ones and repair any cracked panel web.
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Compliance Time
Within the specified intervals as outlined in the AD, starting from the effective date of May 10, 2005.
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Affected Aircraft
All Boeing Model 747 series airplanes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
The FAA is superseding 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 new AD expands the area of inspection, adds a new "secondary" inspection if certain cracking is found, and reduces the intervals for the repetitive inspections. This AD is prompted by a report of an in-flight decompression of a Model 747-100 series airplane that had accumulated 27,241 total flight cycles. We are issuing this 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.
Document Text
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[Federal Register Volume 70, Number 78 (Monday, April 25, 2005)]
[Rules and Regulations]
[Pages 21141-21144]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 05-8098]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2005-21027; Directorate Identifier 2005-NM-048-AD;
Amendment 39-14070; AD 2005-09-02]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule; request for comments.
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SUMMARY: The FAA is superseding 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 new AD expands the
area of inspection, adds a
[[Page 21142]]
new ``secondary'' inspection if certain cracking is found, and reduces
the intervals for the repetitive inspections. This AD is prompted by a
report of an in-flight decompression of a Model 747-100 series airplane
that had accumulated 27,241 total flight cycles. We are issuing this 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.
DATES: Effective May 10, 2005.
The incorporation by reference of Boeing Alert Service Bulletin
747-53A2465, Revision 4, dated February 24, 2005, as listed in the AD,
is approved by the Director of the Federal Register as of May 10, 2005.
On January 27, 2005 (69 FR 76839, December 23, 2004), the Director
of the Federal Register approved the incorporation by reference of
Boeing Service Bulletin 747-53A2465, Revision 1, dated October 16,
2003; and Boeing Alert Service Bulletin 747-53A2465, Revision 2, dated
November 11, 2004.
We must receive any comments on this AD by June 24, 2005.
ADDRESSES: Use one of the following addresses to submit comments on
this AD.
<bullet> DOT Docket Web site: Go to <a href="http://dms.dot.gov">http://dms.dot.gov</a> and follow
the instructions for sending your comments electronically.
<bullet> Government-wide rulemaking Web site: Go to <a href="http://www.regulations.gov">http://www.regulations.gov</a> 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 the contents of this AD docket on the Internet at
<a href="http://dms.dot.gov">http://dms.dot.gov</a>, 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-2005-21027; the directorate identifier for this
docket is 2005-NM-048-AD.
Examining the Docket
You can examine the AD docket on the Internet at <a href="http://dms.dot.gov">http://dms.dot.gov</a>, 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: 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: On December 7, 2004, we issued AD 2004-25-
23, amendment 39-13911 (69 FR 76839, December 23, 2004). That AD
applies to 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 was prompted by reports indicating that cracks
have been found on the top and side panel webs and side panel
horizontal stiffeners of the NWW on Boeing Model 747 series airplanes.
Investigation revealed that the cracking was due to fatigue. The
actions specified in that AD are intended 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 AD Was Issued
Since we issued that AD, the FAA has received a report of an in-
flight decompression on a Boeing Model 747-100 series airplane. The
airplane landed safely, and investigation revealed that the right-hand
side panel web of the NWW was torn open between station (STA) 260 and
STA 280, and from water line (WL) 160 to WL 170. The decompression also
caused damage to the nose landing gear doors and adjacent structure.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin (ASB) 747-53A2465,
Revision 4, dated February 24, 2005. The ASB describes procedures for
performing repetitive external detailed and ultrasonic inspections for
cracking of the top and side panel webs (Areas 1 and 2) of the NWW and
for performing repetitive internal detailed and surface high frequency
eddy current inspections (Area 3) for cracking of the top and side
panel stiffeners of the NWW; replacing cracked stiffeners with new
stiffeners; and repairing any cracked panel web. Revision 4 of the ASB
also describes detailed ``secondary inspections'' for certain cracking
found and specifies contacting Boeing for further action if other
cracking is found. Revision 4 of the ASB describes procedures for
expanding the area of inspection of the web from STA 260 to STA 270
along WL 140. Revision 4 of the ASB also specifies reducing the
repetitive inspection intervals for Area 1 and Area 2 and includes
additional repetitive detailed and ultrasonic (UT) inspections.
Revision 4 of the ASB also describes reducing the repetitive inspection
intervals for the inspections of Area 3.
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. This AD is being
issued to supersede AD 2004-25-23. This new AD continues 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
AD expands the area of inspection, adds a new ``secondary'' inspection
if certain cracking is found, and reduces the repetitive inspection
intervals.
Differences Between the AD and Revision 4 of the ASB
Although the ASB specifies that operators may contact the
manufacturer for disposition of certain repair conditions, this AD
requires operators to repair those conditions according to a method
approved by the FAA. Although the ASB specifies certain initial
inspection compliance times relative to January 27, 2005 (the effective
date of AD 2004-25-23), this AD requires those certain initial
inspection compliance times in relation to the effective date of this
AD. While the ASB describes reducing the current repetitive inspection
intervals for Area 3 from 6,000 flight cycles to 1,500 flight cycles,
this AD does not require the reduced intervals. Requiring the
repetitive intervals at 1,500 flight cycles would allow adequate time
for public opportunity to comment, and we would issue a proposed AD to
provide that comment period. Therefore, we may consider further
rulemaking to address this issue. In addition, the ASB specifies that
operators should report inspection results to the manufacturer, but
this AD does not require those inspection results to be reported.
[[Page 21143]]
Change to Existing AD
This AD would retain certain requirements of AD 2004-25-23. Since
AD 2004-25-23 was issued, the AD format has been revised, and certain
paragraphs have been rearranged. As a result, the corresponding
paragraph identifiers have changed in this AD, as listed in the
following table:
Revised Paragraph Identifiers
------------------------------------------------------------------------
Corresponding requirement in
Requirement in AD 2004-25-23 this AD
------------------------------------------------------------------------
Paragraph (a)............................ Paragraph (f).
------------------------------------------------------------------------
Interim Action
This is considered to be interim action. As previously discussed,
we may consider further rulemaking regarding reducing certain
repetitive inspection intervals. In addition, the manufacturer has
advised that it currently is developing a modification that will
address the unsafe condition addressed by this AD. Once this
modification is developed, approved, and available, the FAA may
consider additional rulemaking.
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-2005-21027;
Directorate Identifier 2005-NM-048-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 <a href="http://dms.dot.gov">http://dms.dot.gov</a> 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
<a href="http://dms.dot.gov">http://dms.dot.gov</a>.
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 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 part 39 of the Federal Aviation Regulations (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 removing amendment 39-13911 (69 FR
76839, December 23, 2004), and adding the following new airworthiness
directive (AD):
2005-09-02 Boeing: Docket No. FAA-2005-21027; Directorate Identifier
2005-NM-048-AD; Amendment 39-14070.
Effective Date
(a) This AD becomes effective May 10, 2005.
Affected ADs
(b) This AD supersedes AD 2004-25-23, amendment 39-13911 (69 FR
76839, December 23, 2004).
Applicability
(c) This AD applies to all Boeing Model 747 series airplanes,
certificated in any category.
Unsafe Condition
(d) This AD was prompted by a report of an in-flight
decompression of a Model 747-100 series airplane that had
accumulated 27,241 total flight cycles. We are issuing this AD to
detect and correct 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 could 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 Certain Requirements of AD 2004-25-23
Initial and Repetitive Inspections
(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), whichever is later, do the inspections
specified in either paragraph (f)(1) or (f)(2) of this AD.
(1) Do the inspections specified in paragraphs (f)(1)(i) and
(f)(1)(ii) of this AD in accordance with the Accomplishment
Instructions of Boeing Service Bulletin 747-53A2465, Revision 1,
dated October 16, 2003. Repeat the inspections thereafter at
intervals not to exceed 1,000 flight cycles.
[[Page 21144]]
(i) Do detailed and ultrasonic inspections of the top and side
panel webs of the NWW for cracks.
(ii) Do detailed and surface high frequency eddy current (HFEC)
inspections of the top and side panel stiffeners of the NWW for
cracks.
(2) Do the inspections specified in paragraphs (f)(2)(i) and
(f)(2)(ii) of this AD in accordance with the Accomplishment
Instructions of Boeing Alert Service Bulletin 747-53A2465, Revision
2, dated November 11, 2004. Repeat the inspections thereafter at the
intervals specified in paragraphs (f)(2)(i) and (f)(2)(ii) of this
AD.
(i) Do external detailed inspections of the top and side panel
webs of the NWW (specified as Area 1 and Area 2 in the service
bulletin), as applicable, for cracks. Repeat the inspections
thereafter at intervals not to exceed 1,000 flight cycles.
(ii) Do internal detailed and surface HFEC inspections of the
top and side panel stiffeners of the NWW (specified as Area 3 in the
service bulletin) for cracks. Repeat the inspections thereafter at
intervals not to exceed 6,000 flight cycles.
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.''
New Requirements of This AD
(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 Alert Service Bulletin (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. Accomplishment
of this inspection terminates the requirements for the inspections
specified in paragraphs (f)(1)(i) and (f)(2)(i) 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 the effective
date of this AD, 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 the effective date of this
AD.
Repetitive Inspections
(h) Repeat the inspection required by paragraph (g) of this AD
at the intervals specified in paragraph (h)(1) or (h)(2) of this AD,
as applicable.
(1) For airplanes with less than 20,000 total flight cycles as
of the effective date of this AD, 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 sidewall panel web 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 within 90 days after the
effective date of this AD, 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) 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.
Inspections and corrective actions accomplished before the effective
date of this AD, in accordance with Boeing Service Bulletin 747-
53A2465, Revision 1, dated October 16, 2003; Revision 2, dated
November 11, 2004; and Revision 3, dated December 23, 2004; are
considered acceptable for compliance with the corresponding
inspections specified in paragraphs (g) and (h) of this AD.
Certain Other Corrective Actions
(l) Where the ASB specifies contacting the manufacturer if
certain cracking is found, this AD requires repairing the cracking
according to a method approved by the Manager, Seattle Aircraft
Certification Office (ACO), FAA, or by an Authorized Representative
for the Boeing Delegation Option Authorization Organization who has
been authorized by the Manager, Seattle ACO, to make those findings.
The repair must be accomplished before further flight. For a repair
method to be approved by the Manager, Seattle ACO, as required by
this paragraph, the Manager's approval letter must specifically
refer to this AD.
No Reporting Requirements
(m) Although the Boeing ASB specifies that operators should
report inspection results to the manufacturer, this AD does not
require those inspection results to be reported.
Alternative Methods of Compliance (AMOCs)
(n)(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 an
Authorized Representative for the Boeing 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, and the approval must specifically refer to this AD.
Material Incorporated by Reference
(o) You must use Boeing Service Bulletin 747-53A2465, Revision
1, dated October 16, 2003; Boeing Alert Service Bulletin 747-
53A2465, Revision 2, dated November 11, 2004; and Boeing Alert
Service Bulletin 747-53A2465, Revision 4, dated February 24, 2005;
as applicable, to perform the actions that are required by this AD,
unless the AD specifies otherwise.
(1) The incorporation by reference of Boeing Alert Service
Bulletin 747-53A2465, Revision 4, dated February 24, 2005, is
approved by the Director of the Federal Register in accordance with
5 U.S.C. 552(a) and 1 CFR part 51.
(2) The incorporation by reference of Boeing Service Bulletin
747-53A2465, Revision 1, dated October 16, 2003; and Boeing Alert
Service Bulletin 747-53A2465, Revision 2, dated November 11, 2004;
was approved previously by the Director of the Federal Register as
of January 27, 2005 (69 FR 76839, December 23, 2004).
(3) To get copies of the service information, contact Boeing
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.
To view the AD docket, go to the Docket Management Facility, U.S.
Department of Transportation, 400 Seventh Street SW., room PL-401,
Nassif Building, Washington, DC. To review copies of the service
information, go to the National Archives and Records Administration
(NARA). For information on the availability of this material at the
NARA, call (202) 741-6030, or go to <a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.
Issued in Renton, Washington, on April 13, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-8098 Filed 4-22-05; 8:45 am]
BILLING CODE 4910-13-P
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