[Federal Register Volume 68, Number 53 (Wednesday, March 19, 2003)]
[Proposed Rules]
[Pages 13239-13242]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-6506]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-120-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to all EMBRAER Model EMB-120 series 
airplanes, that would have required replacing certain existing 
potentiometers with recently manufactured potentiometers, modifying the 
flexible couplers that attach the shafts of the potentiometers to the 
shafts of the primary flight controls, performing repetitive 
calibration tests of the potentiometers and obtaining repetitive 
readouts of the flight data recorder (FDR), and reporting the results 
to the FAA. This new action proposes initial and repetitive testing of 
the potentiometers to detect noisy signals and replacement of only 
those with noisy signals. The actions specified by this new proposed AD 
are intended to prevent the potentiometers that provide

[[Page 13240]]

information on the positions of the primary flight controls to the FDR 
from transmitting noisy signals or becoming improperly calibrated, 
resulting in the transmission of incomplete or inaccurate data to the 
FDR. This lack of reliable data could hamper discovery of the unsafe 
condition which caused an accident or an incident and prevent the FAA 
from developing and mandating actions to prevent additional incidents 
or accidents caused by that same unsafe condition.

DATES: Comments must be received by April 14, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-120-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: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-120-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 the proposed rule 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 Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Robert D. Breneman, Aerospace 
Engineer, International Branch, ANM-116, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; 
telephone (425) 227-1263; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] 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 proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-120-AD.'' The postcard will be date stamped 
and returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2000-NM-120-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR 39) to add an airworthiness directive (AD), applicable to all 
EMBRAER Model EMB-120 series airplanes, was published as a notice of 
proposed rulemaking (NPRM) in the Federal Register on April 27, 2001 
(66 FR 21107). That NPRM would have required replacing certain existing 
potentiometers with recently manufactured potentiometers, modifying the 
flexible couplers that attach the shafts of the potentiometers to the 
shafts of the primary flight controls, performing repetitive 
calibration tests of the potentiometers and obtaining repetitive 
readouts of the flight data recorder (FDR), and reporting the results 
to the FAA. Those actions were intended to prevent the potentiometers 
that provide information on the positions of the primary flight 
controls to the FDR from transmitting noisy signals or becoming 
improperly calibrated, resulting in the transmission of incomplete or 
inaccurate data to the FDR. This lack of reliable data could hamper 
discovery of the unsafe condition which caused an accident or an 
incident and prevent the FAA from developing and mandating actions to 
prevent additional incidents or accidents caused by that same unsafe 
condition.

Comments

    Due consideration has been given to the comments received in 
response to the original NPRM.

Request to Change Applicability

    One commenter requests that the applicability of the NPRM be 
changed from ``all Model EMB-120 series airplanes'' to ``All Model EMB-
120 series airplanes with a Flight Data Recorder installed or required 
by the Federal Aviation Regulations, certificated in any category.'' 
The commenter points out that some Model EMB-120 series airplanes have 
been converted from passenger operation to freighter operation and, 
therefore, are no longer required to operate with FDRs. The FAA agrees 
and has changed this AD so that it applies to ``Model EMB-120 series 
airplanes which are required by 14 CFR 135 to operate with a flight 
data recorder (FDR), certificated in any category.''

Request To Change Requirement to Replace All In-service Potentiometers

    Three commenters request that the proposed replacement of all in-
service potentiometers with potentiometers manufactured less than 12 
months ago be changed. The commenters suggest instead that a download 
of the FDR testing data be performed to identify potentiometers with 
noisy signals and that only those potentiometers should be replaced.
    The FAA agrees. EMBRAER has developed a procedure for determining 
whether or not a potentiometer has a noisy signal. That procedure has 
been incorporated into Section 31-30-00 of the EMBRAER Model EMB-120 
Airplane Maintenance Manual (AMM), dated April 10, 2002. Accordingly, 
we have revised paragraphs (a), (b), and (c) of this supplemental NPRM 
to require testing of the potentiometers and replacement of those with 
noisy signals.

Request To Change the Interval for Repetitive Calibration and Readout

    The same three commenters request that the interval for the 
repetitive testing of potentiometers be extended from 6

[[Page 13241]]

months to 12 months. The commenters state that the current EMBRAER EMB-
120 Maintenance Review Board (MRB) requirements are for a yearly 
calibration and download test.
    The FAA agrees. We find that the new procedure specified in the AMM 
will detect potentiometers with noisy signals and, thus, agree that the 
current MRB requirements for a yearly download are sufficient. We have 
changed the language of this proposed AD accordingly.

Request To Delete Requirement for Modification of the Flexible Couplers

    One commenter requests that the FAA drop the proposed requirement 
to add locktite to the flexible coupler attachment screws to prevent 
loosening of the attachment screws. The commenter states that a screw 
which is properly installed and torqued should never come loose.
    The FAA does not agree. We have had multiple reports of couplers 
coming loose and shifting the calibration; such a shift in calibration 
would not be discovered until the next readout of the FDR. Accordingly, 
no such change has been made to this proposed AD.

Request To Delete Reporting Requirement

    One commenter requests that the proposed requirement to report 
results of the calibration test and readout be deleted. The commenter 
states that the requirement is unnecessary and imposes a hardship on 
operators.
    The FAA agrees in part. We have dropped the reporting requirement 
in this AD, because we find that EMBRAER's procedure for detecting 
potentiometers with noisy signals will detect them and, therefore, 
reporting the results to the FAA, as proposed in the NPRM, is not 
necessary. Therefore, we have deleted the reporting requirement.

Request To Allow Use of Revised Issue of Service Bulletin

    One commenter asks that use of EMBRAER Service Bulletin 120-31-
0038, Change 02, dated June 25, 1998, be allowed in addition to the 
original issue, dated February 22, 1997. The commenter indicates that 
there is no difference in technical content between the original issue 
and Change 02 of the service bulletin. The FAA concurs and has revised 
the language of this proposed AD accordingly.

Conclusion

    Since these changes expand the scope of the originally proposed 
rule, the FAA has determined that it is necessary to reopen the comment 
period to provide additional opportunity for public comment.

Cost Impact

    The FAA estimates that 250 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 3 work 
hours to perform the noise check of the potentiometers and obtain a 
readout of the FDR, that it would take approximately 1 work hour to 
apply adhesive to the flexible couplers, and that the average labor 
rate is $60 per work hour. The cost impact of the proposed AD on U.S. 
operators for the initial or repetitive testing of an airplane is as 
shown on the following table:

                   Table.--Estimated Cost Impact of AD
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                                 Work hours/      Cost/       Cost for
            Action                airplane      airplane     U.S. fleet
------------------------------------------------------------------------
Adjust potentiometers, perform             3          $180       $45,000
 noise check of potentiometer,
 and obtain readout of FDR....
Apply adhesive to flexible                 1            60        15,000
 couplers.....................
                               ---------------
    Totals....................             4           240        60,000
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    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

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.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 
will not have a significant economic impact, positive or negative, on a 
substantial number of small entities under the criteria of the 
Regulatory Flexibility Act. A copy of the draft regulatory evaluation 
prepared for this action is contained in the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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:

Empresa Brasileira de Aeronautica S.A. (EMBRAER): Docket 2000-NM-
120-AD.

    Applicability: Model EMB-120 series airplanes which are required 
by 14 CFR 135 to operate with a flight data recorder (FDR), 
certificated in any category.

    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 (e) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or

[[Page 13242]]

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 the potentiometers that provide information on the 
positions of the primary flight controls to the FDR from 
transmitting noisy signals or becoming improperly calibrated, 
resulting in the transmission of incomplete or inaccurate data to 
the FDR, accomplish the following:

Initial Testing of Potentiometers

    (a) Within 6 months after the effective date of this AD: Adjust 
the potentiometers to the ailerons, elevators, and rudder; perform a 
noise check of the potentiometers; and obtain a readout of the FDR, 
in accordance with Section 31-30-00 of the EMBRAER EMB-120 Airplane 
Maintenance Manual, dated April 10, 2002.

Repetitive Testing of Potentiometers

    (b) Repeat the noise check of the potentiometers and obtain a 
readout of the FDR, as required by paragraph (a) of this AD, at 
intervals not to exceed 12 months.

Replacement of Potentiometers

    (c) If any readout of the FDR, conducted in accordance with 
paragraphs (a) or (b) of this AD, indicates a potentiometer with a 
noisy signal: Within 20 days after obtaining the readout, replace 
the potentiometer in accordance with Section 31-30-05 of EMBRAER 
EMB-120 Airplane Maintenance Manual, dated July 17, 1998, with one 
that has a date of manufacture no greater than 12 months from the 
date of installation.

Modification of Flexible Coupler

    (d) Prior to further flight, after the accomplishment of 
paragraph (a) of this AD: Apply locktite adhesive over the threads 
of the screws of the flexible couplers that attach the shafts of the 
potentiometers to the shafts of the primary flight controls, in 
accordance with EMBRAER Service Bulletin 120-31-0038, original 
issue, dated February 22, 1997; or Change 02, dated June 25, 1998.

Alternative Methods of Compliance

    (e) 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 2: 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

    (f) Special flight permits may be issued in accordance with 
Sec. Sec.  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.

    Note 3: The subject of this AD is addressed in Brazilian 
airworthiness directive 97-08-01, dated August 29, 1997.


    Issued in Renton, Washington, on March 13, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-6506 Filed 3-18-03; 8:45 am]
BILLING CODE 4910-13-P