AD 2002-08-10
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | 747 | Airworthiness Directives; Boeing Model 747 Series Airplanes |
Unsafe Condition
Cracked or broken alloy steel bolts on the body station 1480 bulkhead splice could result in structural damage and rapid depressurization of the airplane.
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Required Actions
Inspect all alloy steel bolts on the body station 1480 bulkhead splice for cracks or breaks. Replace any cracked or broken bolts as necessary.
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Compliance Time
Before further flight
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Affected Aircraft
Boeing Model 747 series airplanes with the specified alloy steel bolts on the body station 1480 bulkhead splice.
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Federal Register Abstract
This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes. This action requires a one-time inspection to identify all alloy steel bolts on the body station 1480 bulkhead splice, and corrective action if necessary. This action provides for optional terminating action for certain requirements of this AD. This action is necessary to detect and correct cracked or broken bolts, which could result in structural damage and rapid depressurization of the airplane. This action is intended to address the identified unsafe condition.
Document Text
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[Federal Register Volume 67, Number 78 (Tuesday, April 23, 2002)]
[Rules and Regulations]
[Pages 19641-19644]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 02-9570]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2002-NM-69-AD; Amendment 39-12718; AD 2002-08-10]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
[[Page 19642]]
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to certain Boeing Model 747 series airplanes. This action
requires a one-time inspection to identify all alloy steel bolts on the
body station 1480 bulkhead splice, and corrective action if necessary.
This action provides for optional terminating action for certain
requirements of this AD. This action is necessary to detect and correct
cracked or broken bolts, which could result in structural damage and
rapid depressurization of the airplane. This action is intended to
address the identified unsafe condition.
DATES: Effective May 8, 2002.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of May 8, 2002.
Comments for inclusion in the Rules Docket must be received on or
before June 24, 2002.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2002-NM-69-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 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#6f56420e010242060e1d0c0002020a011b2f090e0e41080019"><span class="__cf_email__" data-cfemail="bd8490dcd3d090d4dccfded2d0d0d8d3c9fddbdcdc93dad2cb">[email protected]</span></a>. Comments sent via fax or the Internet must
contain ``Docket No. 2002-NM-69-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: Rick Kawaguchi, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-1153; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: The FAA has received reports of broken alloy
steel bolts on the body station (BS) 1480 bulkhead splice on Boeing
Model 747 series airplanes. This splice connects the upper and lower
pieces of the BS 1480 bulkhead and the overwing longeron. The maximum
number of broken bolts found on an airplane was 10; that airplane was
shown to be unable to withstand limit load. Broken splice bolts were
found on one airplane with only 6,229 total flight cycles and 37,440
total flight hours. All of the broken splice bolts found on the
airplanes were made from H11 alloy steel, which has been found to be
susceptible to stress corrosion and consequent cracking and breakage.
Cracked or broken bolts on the bulkhead splice, if not corrected, could
result in structural damage and rapid depressurization of the airplane.
Related AD
AD 2001-11-06, amendment 39-12248 (66 FR 31124, June 11, 2001),
applicable to certain Boeing Model 747 series airplanes, requires,
among other things, repetitive inspections to detect cracking of
certain areas of the BS 1480 bulkhead. AD 2001-11-06 focuses more on
the skin splice plate and outer chord splice fitting than the mating
bolts. However, airplanes on which the bulkhead splice areas have been
modified in accordance with AD 2001-11-06 are excluded from the
applicability of this AD. Also, inspections of the bulkhead splice area
in accordance with AD 2001-11-06 meet the inspection requirements of
this AD, provided that the bolts are inspected using magnetic particle
methods before they are reinstalled.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
747-53A2477, dated February 28, 2002, which describes procedures for a
one-time inspection using a magnet to identify all alloy steel bolts on
the BS 1480 bulkhead splice, and an inspection using torque test or
ultrasonic methods of all alloy steel bolts to determine if any are
cracked or broken. Corrective actions include replacement of any
cracked or broken alloy steel bolts with Inconel 718 bolts; an
ultrasonic inspection--if any bolt on the splice was found cracked--of
any remaining alloy steel bolt that was inspected using torque test
methods; and repetitive inspections of the remaining serviceable alloy
steel bolts. The alert service bulletin specifies that replacement of
all alloy steel bolts on the splice eliminates the need for the
corrective actions for the alloy steel bolts.
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 detect and correct cracked or broken bolts on the BS
1480 bulkhead splice, which could result in structural damage and rapid
depressurization of the airplane. This action is intended to address
the identified unsafe condition. This AD requires accomplishment of the
actions specified in the alert service bulletin described previously,
except as described below.
Differences Between AD and Alert Service Bulletin
Although the alert service bulletin specifies that the manufacturer
may be contacted for disposition of certain repair conditions, this AD
requires the repair of those conditions to be accomplished in
accordance with 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.
Interim Action
This is considered to be interim action. The FAA is currently
considering requiring the replacement of all alloy steel bolts on the
BS 1480 bulkhead splice, which would terminate the torque tests and
ultrasonic inspections required by this AD. However, the planned
compliance time for this action is long enough to provide adequate
notice and opportunity for prior public comment.
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.
[[Page 19643]]
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 2002-NM-69-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:
2002-08-10 Boeing: Amendment 39-12718. Docket 2002-NM-69-AD.
Applicability: Model 747 series airplanes, certificated in any
category, line numbers 1 through 750 inclusive, excluding airplanes
on which the bulkhead splice areas have been modified in accordance
with Plan ``B'' of AD 2001-11-06, amendment 39-12248.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise 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
alternative method of compliance in accordance with paragraph (g) 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 detect and correct cracked or broken alloy steel bolts on the
body station (BS) 1480 bulkhead splice and consequent structural
damage and rapid depressurization of the airplane, accomplish the
following:
Inspection
(a) At the applicable time specified by paragraph (a)(1) or
(a)(2) of this AD: Inspect the BS 1480 bulkhead splice to identify
all alloy steel bolts by using a magnet or, if applicable, detailed
visual methods, in accordance with Boeing Alert Service Bulletin
747-53A2477, dated February 28, 2002.
Note 2: For the purposes of this AD, a detailed visual
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.''
(1) For airplanes on which the bulkhead splice inspection
specified by AD 2001-11-06 has NOT been accomplished within 15
months before the effective date of this AD: Inspect within 90 days
after the effective date of this AD.
(2) For airplanes on which the bulkhead splice inspection
specified by AD 2001-11-06 HAS been accomplished within 15 months
before the effective date of this AD: Inspect within 18 months since
the most recent inspection.
Corrective Actions
(b) For each alloy steel bolt found during the inspection
required by paragraph (a) of this AD: Before further flight, inspect
those bolts using torque test or ultrasonic methods to detect cracks
or breakage, in accordance with Boeing Alert Service Bulletin 747-
53A2477, dated February 28, 2002, except as required by paragraph
(e) of this AD.
(1) For each uncracked and unbroken alloy steel bolt found:
Repeat the inspection specified by paragraph (b) of this AD
thereafter at least every 18 months, until the optional terminating
action of paragraph (d) of this AD is accomplished.
(2) For any cracked or broken bolt found: Before further flight,
replace it with an Inconel 718 bolt. Such replacement terminates the
requirements of this AD for that bolt only.
(3) If any cracked or broken bolt is found anywhere along the
splice during any inspection required by paragraph (b) of this AD:
Before further flight, reinspect, using ultrasonic methods, any
remaining alloy steel bolts that were initially inspected using
torque test methods, and replace any cracked or broken bolt with an
Inconel 718 bolt. Such replacement terminates the requirements of
this AD for that bolt only.
Magnetic Particle Inspection
(c) Plan ``A'' inspections required by AD 2001-11-06 are
acceptable for compliance with the inspection requirements of
paragraph (b) of this AD, provided a magnetic particle inspection
and applicable corrective actions are performed on any alloy steel
bolt removed during any Plan ``A'' inspection before the bolt is
reinstalled. The magnetic particle inspection and corrective actions
must be performed in accordance with Boeing Alert Service Bulletin
747-53A2477, dated February 28, 2002, except as required by
paragraph (e) of this AD.
[[Page 19644]]
Optional Terminating Action
(d) Replacement of all alloy steel bolts in the BS 1480 bulkhead
splice with Inconel 718 bolts, in accordance with Boeing Alert
Service Bulletin 747-53A2477, dated February 28, 2002, except as
required by paragraph (e) of this AD, terminates the requirements of
this AD.
Exceptions to Service Information
(e) If Boeing Alert Service Bulletin 747-53A2477, dated February
28, 2002, specifies to contact Boeing for appropriate action: Before
further flight, repair in accordance with a method approved by the
Manager, Seattle Aircraft Certification Office (ACO), FAA; or in
accordance with 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.
Spares
(f) As of the effective date of this AD, no person may install
an alloy steel bolt on the BS 1480 bulkhead splice on any airplane.
Alternative Methods of Compliance
(g) 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, FAA. 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
(h) 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
(i) Except as required by paragraph (e) of this AD: The actions
must be done in accordance with Boeing Alert Service Bulletin 747-
53A2477, 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
(j) This amendment becomes effective on May 8, 2002.
Issued in Renton, Washington, on April 12, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 02-9570 Filed 4-22-02; 8:45 am]
BILLING CODE 4910-13-U
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