AD 2001-11-09
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Airbus | A330 A340 | Airworthiness Directives; Airbus Model A330 and A340 Series Airplanes |
Unsafe Condition
Entrance of water into the ball nut of the trimmable horizontal stabilizer actuator (THSA), resulting in jamming of the ball transfer path when the water freezes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the ball nut in the area of the transfer tubes for evidence of ball migration, distortion of the collar or transfer tubes, or disconnection of the transfer tubes from the ball nut. Replace the THSA if necessary. Report inspection findings to Airbus.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the applicable compliance time specified in the AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Airbus Model A330 and A340 series airplanes, certificated in any category, equipped with a trimmable horizontal stabilizer actuator (THSA) part number 47172, and on which Airbus Modification 45299 has been performed.
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 certain Airbus Model A330 and A340 series airplanes. This action requires repetitive inspections to detect discrepancies of the transfer tubes and the collar of the ball nut of the trimmable horizontal stabilizer actuator (THSA); and corrective action, if necessary. This action is necessary to prevent degraded operation of the THSA due to the entrance of water into the ball nut. Degraded operation could lead to reduced controllability of the airplane. This action is intended to address the identified unsafe condition.
Document Text
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[Federal Register Volume 66, Number 112 (Monday, June 11, 2001)]
[Rules and Regulations]
[Pages 31143-31145]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-13996]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2001-NM-135-AD; Amendment 39-12252; AD 2001-11-09]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A330 and A340 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 certain Airbus Model A330 and A340 series airplanes.
This action requires repetitive inspections to detect discrepancies of
the transfer tubes and the collar of the ball nut of the trimmable
horizontal stabilizer actuator (THSA); and corrective action, if
necessary. This action is necessary to prevent degraded operation of
the THSA due to the entrance of water into the ball nut. Degraded
operation could lead to reduced controllability of the airplane. This
action is intended to address the identified unsafe condition.
DATES: Effective June 26, 2001.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of June 26, 2001.
Comments for inclusion in the Rules Docket must be received on or
before July 11, 2001.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2001-NM-135-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#231a0e424d4e0e4a4251404c4e4e464d57634542420d444c55"><span class="__cf_email__" data-cfemail="675e4a06090a4a0e061504080a0a0209132701060649000811">[email protected]</span></a>. Comments sent via fax or the Internet must
contain ``Docket No. 2001-NM-135-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
Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex,
France.
[[Page 31144]]
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: Dan Rodina, Aerospace Engineer,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2125; fax (425) 227-1149.
SUPPLEMENTARY INFORMATION: The Direction Generale de l'Aviation Civile
(DGAC), which is the airworthiness authority for France, recently
notified the FAA that an unsafe condition may exist on certain Airbus
Model A330 and A340 series airplanes. The DGAC advises that four cases
of transfer tube disconnection from the ball nut of the trimmable
horizontal stabilizer actuator (THSA) have been detected during
greasing of in-service Model A330 and A340 series airplanes. The cause
was found to be water entering the ball nut of the THSA, resulting in
jamming of the ball transfer path when the water froze. There are three
independent circuits of balls. The loss of one or two circuits does not
impact the THSA operation, as it continues to operate on the remaining
circuits. If three circuits are lost, then the THSA operates on the
fail-safe nut. Due to the high friction between the fail-safe nut and
the screw, THSA operation will be inefficient and it will lock after a
few movements. This degraded operation is not detectable by the flight
crew as long as the THSA is not locked and could damage the screw and
the fail-safe nut. Jamming of the ball transfer paths, if not
corrected, could result in degraded operation of the THSA and
consequent reduced controllability of the airplane.
Explanation of Relevant Service Information
Airbus has issued All Operator Telexes (AOT) A330-27A3088 and A340-
27A4093, both dated April 5, 2001, which describe procedures for
repetitive detailed visual inspections of the ball nut in the area of
the transfer tubes for, among other things, evidence of ball migration
from the ball nut; distortion of the collar or transfer tubes; or
disconnection of the transfer tubes from the ball nut; and replacement
of the THSA, if necessary. The DGAC classified these AOTs as mandatory
and issued French airworthiness directives 2001-141(B) and 2001-140(B),
both dated April 18, 2001, in order to assure the continued
airworthiness of these airplanes in finance.
FAA's Conclusions
These airplane models are manufactured in and are type certificated
for operation in the United States under the provisions of Sec. 21.29
of the Federal Aviation Regulations (14 CFR 21.29) and the applicable
bilateral airworthiness agreement. Pursuant to this bilateral
airworthiness agreement, the DGAC has kept the FAA informed of the
situation described above. The FAA has examined the findings of the
DGAC, reviewed all available information, and determined that AD action
is necessary for products of this type design that are certificated for
operation in the United States.
Explanation of Requirements of Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, this AD is being issued to prevent degraded
operation of the THSA due to the entrance of water into the ball nut,
and consequent reduced controllability of the airplane. This AD
requires accomplishment of the actions specified in the applicable AOT
described previously. This AD also requires that operators report
results of inspection findings to Airbus.
Interim Action
This is considered to be interim action until final action is
identified, at which time the FAA may consider further rulemaking.
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 2001-NM-135-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.
[[Page 31145]]
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:
2001-11-09 Airbus Industrie: Amendment 39-12252. Docket 2001-NM-
135-AD.
Applicability: Model A330 and A340 series airplanes,
certificated in any category, equipped with a trimmable horizontal
stabilizer actuator (THSA) part number 47172, and on which Airbus
Modification 45299 has been performed.
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 (d) 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 prevent degraded operation of the THSA due to the entrance of
water into the ball nut, and consequent reduced controllability of
the airplane, accomplish the following:
Repetitive Inspections
(a) Within 150 flight hours from the effective date of this AD,
perform a detailed visual inspection to detect discrepancies in the
THSA (including distortion of the transfer tubes, disconnection of
the tubes, and distortion of the collar of the ball nut), in
accordance with All Operators Telex (AOT) A330-27A3088 (for Model
A330 series airplanes) or A340-27A4093 (for Model A340 series
airplanes), both dated April 5, 2001, as applicable. If any
discrepancy, as defined in paragraph 4-2-2/Rejection Criteria of the
applicable AOT, is detected, prior to further flight, replace the
THSA with a serviceable one, per the applicable AOT.
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.''
(b) At intervals not to exceed 150 flight hours, repeat the
inspection mandated in paragraph (a) of this AD.
Report of Inspection Findings
(c) Submit a report of inspection findings (both positive and
negative) to Airbus; at the applicable time specified in paragraph
(c)(1) or (c)(2) of this AD. The report must include the inspection
results, a description of any discrepancies found, the airplane
serial number, and the number of landings and flight hours on the
airplane. Information collection requirements contained in this
regulation have been approved by the Office of Management and Budget
(OMB) under the provisions of the Paperwork Reduction Act of 1980
(44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number
2120-0056.
(1) For airplanes on which the inspection is accomplished after
the effective date of this AD: Submit the report within 10 days
after performing the inspection required by paragraph (a) or (b) of
this AD.
(2) For airplanes on which the inspection has been accomplished
prior to the effective date of this AD: Submit the report within 10
days after the effective date of this AD.
Alternative Methods of Compliance
(d) 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, International Branch, ANM-116,
Transport Airplane Directorate, FAA. Operators shall submit their
requests through an appropriate FAA Principal Maintenance Inspector,
who may add comments and then send it to the Manager, International
Branch, ANM-116.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
Special Flight Permits
(e) Special flight permits may be issued in accordance with
Secs. 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
(f) The inspections and replacement shall be done in accordance
with Airbus All Operators Telex A330-27A3088, dated April 5, 2001;
or Airbus All Operators Telex A340-27A4093, dated April 5, 2001; as
applicable. 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 Airbus Industrie, 1
Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. 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.
Note 4: The subject of this AD is addressed in French
airworthiness directives 2001-141(B) and 2001-140(B), both dated
April 18, 2001.
Effective Date
(g) This amendment becomes effective on June 26, 2001.
Issued in Renton, Washington, on May 25, 2001.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 01-13996 Filed 6-8-01; 8:45 am]
BILLING CODE 4910-13-U
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Retrieved: Apr 6, 2026
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