AD Amdt-39-10265

final rule

Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-120 Series Airplanes

AD Number
Amdt-39-10265
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. 97-NM-299-AD
FR Citation
62 FR 67552
Technical illustration of an aircraft flight control surface and actuator
Problem area Flight controls

Applicability

TypeManufacturerModelDetails
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

Show stored source text (verify against official source)
[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.

-----------------------------------------------------------------------

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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