AD Amdt-39-10265
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Embraer | EMB-120 | Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-120 Series Airplanes |
Unsafe Condition
The movable backstop of the elevator pitch trim command system may be out of its proper position or completely out of the cursor gearing, causing autopilot disengagement and sudden pitch attitude change leading to reduced controllability.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Perform a one-time inspection of the movable backstop within 20 flight hours after the effective date to ensure correct installation. Install a guide for the movable backstop within 75 flight hours. Correct discrepancies before further flight if found.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 20 flight hours (inspection) and within 75 flight hours (installation) after the effective date
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
All EMBRAER Model EMB-120 series airplanes, certificated in any category.
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 EMBRAER Model EMB-120 series airplanes. This action requires a one-time inspection of the movable backstop of the elevator pitch trim command system to ensure that it is installed correctly, and corrective action, if necessary. This action also requires installation of a guide to maintain the movable backstop in its correct position. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified in this AD are intended to prevent a sudden change in pitch attitude caused by autopilot disconnect, which could result in reduced controllability of the airplane.
Document Text
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[Federal Register Volume 62, Number 248 (Monday, December 29, 1997)]
[Rules and Regulations]
[Pages 67552-67553]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 97-33667]
[[Page 67552]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-299-AD; Amendment 39-10265; AD 97-26-22]
RIN 2120-AA64
Airworthiness Directives; Empresa Brasileira de Aeronautica S.A.
(EMBRAER) Model EMB-120 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 EMBRAER Model EMB-120 series airplanes. This
action requires a one-time inspection of the movable backstop of the
elevator pitch trim command system to ensure that it is installed
correctly, and corrective action, if necessary. This action also
requires installation of a guide to maintain the movable backstop in
its correct position. This amendment is prompted by issuance of
mandatory continuing airworthiness information by a foreign civil
airworthiness authority. The actions specified in this AD are intended
to prevent a sudden change in pitch attitude caused by autopilot
disconnect, which could result in reduced controllability of the
airplane.
DATES: Effective January 13, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of January 13, 1998.
Comments for inclusion in the Rules Docket must be received on or
before January 28, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 97-NM-299-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
The service information referenced in this AD may be obtained from
Empresa Brasileira de Aeronautica S.A. (EMBRAER), P.O. Box 343--CEP
12.225, Sao Jose dos Campos--SP, Brazil. This information may be
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,
SW., Renton, Washington; or at the FAA, Small Airplane Directorate,
Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix
Boulevard, Suite 450, Atlanta, Georgia; or at the Office of the Federal
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Rob Capezzuto, Aerospace Engineer,
Systems and Flight Test Branch, ACE-116A, FAA, Small Airplane
Directorate, Atlanta Aircraft Certification Office, One Crown Center,
1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349; telephone
(770) 703-6071; fax (770) 703-6097.
SUPPLEMENTARY INFORMATION: The Departmento de Aviacao Civil (DAC),
which is the airworthiness authority for Brazil, recently notified the
FAA that an unsafe condition may exist on all EMBRAER Model EMB-120
series airplanes. The DAC advises that it has received reports of
uncommanded reversion of the elevator trim tab during the descent phase
with the autopilot descent mode engaged. In one case, the movable
backstop of the elevator pitch trim command system was found to be out
of its proper position, which caused the autopilot to disengage when it
reached the pitch down stop position. In another instance, the movable
backstop was found to be completely out of the cursor gearing. This
condition, if not corrected, could result in a sudden change in pitch
attitude and reduced controllability of the airplane.
Explanation of Relevant Service Information
EMBRAER has issued Alert Service Bulletin 120-27-A081, Change 01,
dated October 9, 1997, which describes procedures for a one-time
inspection of the movable backstop of the elevator pitch trim command
system to ensure that it is installed correctly, and corrective action,
if necessary. The alert service bulletin also describes procedures for
installation of a guide to maintain the movable backstop in position in
the spiral groove on the pitch trim right control wheel. The DAC
classified this alert service bulletin as mandatory and issued
Brazilian emergency airworthiness directive 97-09-08R1, dated October
23, 1997, in order to assure the continued airworthiness of these
airplanes in Brazil.
FAA's Conclusions
This airplane model is manufactured in Brazil and is type
certificated for operation in the United States under the provisions of
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, the DAC has kept the FAA informed of
the situation described above. The FAA has examined the findings of the
DAC, 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 will require accomplishment of the
actions specified in the alert service bulletin described previously.
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.
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
[[Page 67553]]
Docket Number 97-NM-299-AD.'' The postcard will be date stamped and
returned to the commenter.
Regulatory Impact
The regulations adopted herein will not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
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:
97-26-22 Empresa Brasileira de Aeronautica S.A. (EMBRAER):
Amendment 39-10265. Docket 97-NM-299-AD.
Applicability: All Model EMB-120 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
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 prevent a sudden change in pitch attitude caused by autopilot
disconnect, which could result in reduced controllability of the
airplane, accomplish the following:
(a) Within 20 flight hours after the effective date of this AD,
perform a one-time inspection of the movable backstop of the
elevator pitch trim command system to ensure that it is installed
correctly, in accordance with Part I of the Accomplishment
Instructions of EMBRAER Alert Service Bulletin 120-27-A081, Change
01, dated October 9, 1997. If any discrepancy is found, prior to
further flight, accomplish follow-on corrective actions, in
accordance with the alert service bulletin.
(b) Within 75 flight hours after the effective date of this AD,
install a guide for the movable backstop of the elevator pitch trim
command system, in accordance with Part II of the Accomplishment
Instructions of EMBRAER Alert Service Bulletin 120-27-A081, Change
01, dated October 9, 1997.
(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, Atlanta Aircraft Certification
Office (ACO), FAA, Small Airplane Directorate. Operators shall
submit their requests through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Atlanta ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Atlanta ACO.
(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.
(e) The actions shall be done in accordance with EMBRAER Alert
Service Bulletin 120-27-A081, Change 01, dated October 9, 1997. 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 Empresa Brasileira de Aeronautica
S.A. (EMBRAER), P.O. Box 343--CEP 12.225, Sao Jose dos Campos--SP,
Brazil. Copies may be inspected at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the
FAA, Small Airplane Directorate, Atlanta Aircraft Certification
Office, One Crown Center, 1895 Phoenix Boulevard, Suite 450,
Atlanta, Georgia; or at the Office of the Federal Register, 800
North Capitol Street, NW., suite 700, Washington, DC.
Note 3: The subject of this AD is addressed in Brazilian
emergency airworthiness directive 97-09-08R1, dated October 23,
1997.
(f) This amendment becomes effective on January 13, 1998.
Issued in Renton, Washington, on December 19, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-33667 Filed 12-24-97; 8:45 am]
BILLING CODE 4910-13-U
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Retrieved: Apr 6, 2026
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