AD 2002-06-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | 747 | Airworthiness Directives; Boeing Model 747 Series Airplanes |
Unsafe Condition
Cracking of the upper skin of the horizontal stabilizer center section and the rear spar upper chord, which could lead to reduced structural capability and loss of controllability.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect for cracking of the upper skin of the horizontal stabilizer center section and the rear spar upper chord. Repair any identified cracking as necessary.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 50 flight hours after the effective date of the AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
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
This amendment adopts a new airworthiness directive (AD) that is applicable to all Boeing Model 747 series airplanes. This action requires repetitive inspections for cracking of the upper skin of the horizontal stabilizer center section and the rear spar upper chord, and repair, if necessary. This action is necessary to find and fix such cracking, which could lead to reduced structural capability of the horizontal stabilizer center section, and result in loss of controllability of the airplane. This action is intended to address the identified unsafe condition.
Document Text
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[Federal Register Volume 67, Number 53 (Tuesday, March 19, 2002)]
[Rules and Regulations]
[Pages 12464-12466]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 02-6329]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2002-NM-32-AD; Amendment 39-12678; AD 2002-06-02]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to all Boeing Model 747 series airplanes. This action
requires repetitive inspections for cracking of the upper skin of the
horizontal stabilizer center section and the rear spar upper chord, and
repair, if necessary. This action is necessary to find and fix such
cracking, which could lead to reduced structural capability of the
horizontal stabilizer center section, and result in loss of
controllability of the airplane. This action is intended to address the
identified unsafe condition.
DATES: Effective April 3, 2002.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of April 3, 2002.
Comments for inclusion in the Rules Docket must be received on or
before May 20, 2002.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2002-NM-32-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9 a.m. and 3 p.m., Monday through Friday, except
Federal holidays. Comments may be submitted via fax to (425) 227-1232.
Comments may also be sent via the Internet using the following address:
<a href="/cdn-cgi/l/email-protection#d0e9fdb1bebdfdb9b1a2b3bfbdbdb5bea490b6b1b1feb7bfa6"><span class="__cf_email__" data-cfemail="fac3d79b9497d7939b88999597979f948eba9c9b9bd49d958c">[email protected]</span></a>. Comments sent via fax or the Internet must
contain ``Docket No. 2002-NM-32-AD'' in the subject line and need not
be submitted in triplicate. Comments sent via the Internet as attached
electronic files must be formatted in Microsoft Word 97 for Windows or
ASCII text.
The service information referenced in this AD may be obtained from
Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington
98124-2207. This information may be examined at the FAA, Transport
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at
the Office of the Federal Register, 800 North Capitol Street, NW.,
suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Tamara Anderson, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2771; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: The FAA has received a report that a 3.5-
inch crack was found in the upper skin of the horizontal stabilizer
center section on a Boeing Model 747SR series airplane. The crack ran
forward from the rear spar at left buttock line (LBL) 37.8. While the
area where the crack was found is subject to inspections per a certain
Supplemental Structural Inspection Document (SSID), the airplane on
which the crack was found was not an SSID candidate. Such cracking, if
not fixed, could lead to reduced structural capability of the
horizontal stabilizer center section, which could result in loss of
controllability of the airplane.
[[Page 12465]]
The subject area on all Model 747 series airplanes is similar to
that on the affected Model 747SR series airplane. Therefore, all of
these airplanes may be subject to the same unsafe condition.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
747-55A2050, dated February 28, 2002, which describes procedures for
repetitive detailed and high frequency eddy current (HFEC) inspections
for cracking of the upper skin of the horizontal stabilizer center
section and the rear spar upper chord. The procedures include a
detailed visual inspection for cracking of the upper horizontal skin
and of the vertical and horizontal flanges of the rear spar upper
chord, and an HFEC inspection for cracking of the vertical flange of
the upper chord where a detailed visual inspection is impeded by
stiffeners, brackets, or sealant. The service bulletin specifies to
contact Boeing for repair of any crack that is found. Accomplishment of
the actions specified in the service bulletin is intended to adequately
address the identified unsafe condition.
Explanation of the Requirements of the Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design, this AD is
being issued to find and fix cracking of the upper skin of the
horizontal stabilizer center section and the rear spar upper chord,
which could lead to reduced structural capability of the horizontal
stabilizer center section, and result in loss of controllability of the
airplane. This AD requires accomplishment of the actions specified in
the service bulletin described previously, except as discussed below.
Differences Between This AD and the Service Bulletin
Operators should note that, although the service bulletin specifies
that the manufacturer may be contacted for disposition of repair
conditions, this AD requires the repair of those conditions to be
accomplished per a method approved by the FAA, or per data meeting the
type certification basis of the airplane approved by a Boeing Company
Designated Engineering Representative who has been authorized by the
Manager, Seattle Aircraft Certification Office, to make such findings.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this rule by
submitting such written data, views, or arguments as they may desire.
Communications shall identify the Rules Docket number and be submitted
in triplicate to the address specified under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Submit comments using the following format:
<bullet> Organize comments issue-by-issue. For example, discuss a
request to change the compliance time and a request to change the
service bulletin reference as two separate issues.
<bullet> For each issue, state what specific change to the AD is
being requested.
<bullet> Include justification (e.g., reasons or data) for each
request.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the rule. All comments submitted will be
available, both before and after the closing date for comments, in the
Rules Docket for examination by interested persons. A report that
summarizes each FAA-public contact concerned with the substance of this
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 2002-NM-32-AD.'' The postcard will be date stamped and
returned to the commenter.
Regulatory Impact
The regulations adopted herein 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. Therefore, it
is determined that this final rule does not have federalism
implications under Executive Order 13132.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the Rules Docket.
A copy of it, if filed, may be obtained from the Rules Docket at the
location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends part 39 of
the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new
airworthiness directive:
2002-06-02 Boeing: Amendment 39-12678. Docket 2002-NM-32-AD.
Applicability: All Model 747 series airplanes; certificated in
any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
[[Page 12466]]
alternative method of compliance in accordance with paragraph (c) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To find and fix cracking of the upper skin of the horizontal
stabilizer center section and the rear spar upper chord, which could
lead to reduced structural capability of the horizontal stabilizer
center section, and result in loss of controllability of the
airplane, accomplish the following:
Repetitive Inspections
(a) Before the accumulation of 24,000 total flight cycles, or
within 90 days after the effective date of this AD, whichever occurs
later: Do detailed and high frequency eddy current (HFEC)
inspections, as applicable, for cracking of the upper skin of the
horizontal stabilizer center section and the rear spar upper chord,
according to the Work Instructions and Figure 1 of Boeing Alert
Service Bulletin 747-55A2050, dated February 28, 2002. (The
inspection procedures include a detailed inspection for cracking of
the upper horizontal skin and of the vertical and horizontal flanges
of the rear spar upper chord, and an HFEC inspection for cracking of
the vertical flange of the upper chord where a detailed inspection
is impeded by the presence of stiffeners, brackets, or sealant.)
After doing the initial inspections, repeat the inspections every
1,000 flight cycles.
Note 2: 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 mirror,
magnifying lenses, etc., may be used. Surface cleaning and elaborate
access procedures may be required.''
Repair
(b) If any cracking is found during any inspection per paragraph
(a) of this AD: Before further flight, repair per 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
who has been authorized by the Manager, Seattle ACO, to make such
findings. For a repair method to be approved by the Manager, Seattle
ACO, as required by this paragraph, the Manager's approval letter
must specifically reference this AD.
Alternative Methods of Compliance
(c) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Seattle ACO. Operators shall submit
their requests through an appropriate FAA Principal Maintenance
Inspector, who may add comments and then send it to the Manager,
Seattle ACO.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
Special Flight Permits
(d) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
Incorporation by Reference
(e) The actions shall be done in accordance with Boeing Alert
Service Bulletin 747-55A2050, dated February 28, 2002. This
incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from Boeing Commercial Airplane Group,
P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be
inspected at the FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton, Washington; or at the Office of the Federal
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
Effective Date
(f) This amendment becomes effective on April 3, 2002.
Issued in Renton, Washington, on March 11, 2002.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 02-6329 Filed 3-18-02; 8:45 am]
BILLING CODE 4910-13-P
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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