[Federal Register: February 1, 2005 (Volume 70, Number 20)]
[Proposed Rules]
[Page 5070-5073]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01fe05-16]
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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 (FAA), Department of
Transportation (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 certain EMBRAER Model EMB-120 series
airplanes that would have required initial and repetitive calibration
testing of potentiometers to detect noisy signals and replacement of
only those with noisy signals. This new action revises the proposed AD
by reducing the compliance time for the repetitive calibration testing
of the potentiometers and adding the requirement for reporting results
of the calibration tests of the potentiometers and the readouts of the
flight data recorder (FDR) to the airplane manufacturer. The actions
specified by this new proposed AD are 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 that caused an accident or incident
and prevent the FAA from developing and mandating actions to prevent
additional accidents or incidents caused by that same unsafe condition.
This action is intended to address the identified unsafe condition.
DATES: Comments must be received by February 28, 2005.
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:
9-anm-nprmcomment@faa.gov. 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 or 2000 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: Todd Thompson, Aerospace Engineer,
International Branch, ANM-116, Transport Airplane Directorate, 1601
Lind Avenue, S.W., Renton, Washington, 98055-4056; telephone (425) 227-
1175; 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:
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.
For each issue, state what specific change to the proposed
AD is being requested.
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 part 39) to add an airworthiness directive (AD), applicable to
certain EMBRAER Model EMB-120 series airplanes, was published as a
supplemental notice of proposed rulemaking (NPRM) in the Federal
Register on March 19, 2003 (68 FR 13239), hereafter referred to as the
``first supplemental NPRM.'' That supplemental NPRM would have required
initial and repetitive calibration testing of the potentiometers to
detect noisy signals and replacement of only those with noisy signals.
Potentiometers that provide information on the positions of the primary
flight controls to the flight data recorder (FDR) transmitting noisy
signals or becoming improperly calibrated, if not corrected, could
result in the transmission of incomplete or inaccurate data to the FDR.
This lack of reliable data could hamper discovery of the unsafe
condition that caused an accident or incident and prevent the FAA from
developing and mandating actions to prevent additional accidents or
incidents caused by that same unsafe condition.
[[Page 5071]]
Comments Received to the First Supplemental NPRM
Due consideration has been given to the comments received in
response to the first supplemental NPRM.
Request To Reduce Compliance Time
The commenter, the National Transportation Safety Board (NTSB),
requests that the compliance time interval for the repetitive
calibration tests of the potentiometers and the readouts of the FDR in
the first supplemental NPRM be changed from 12 months back to the 6
months proposed in the original NPRM. The commenter states that it
closed Safety Recommendation A-96-34 in 1998 with an acceptable status,
because the original NPRM and the FAA Flight Standards Handbook
Bulletin for Airworthiness 97-14 (EMBRAER EMB-120 Flight Data Recorder
Test), directed potentiometer calibration testing every 6 months. Since
the original NPRM was issued, the commenter points out that the FAA
reversed its position on these inspections by proposing to require
annual inspections in the first supplemental NPRM. The commenter states
it has found sensor failures to be intermittent and believes that,
because annual inspections are the typical inspection cycle for FDR
systems, they may not reveal a problem and will not provide timely
feedback on the effectiveness of the corrective action, possibly
resulting in a failed sensor remaining in place for a full year.
The FAA agrees. Sensor failures can be intermittent; therefore, we
have determined that annual inspections--the typical inspection cycle
for FDR systems--may not reveal a problem in a timely manner and could
possibly result in a failed sensor remaining in place for up to a year.
We have revised paragraph (b) of this second supplemental NPRM to
reduce the compliance time interval for the repetitive calibration
tests of the potentiometers and the readouts of the FDR from 12 months
back to 6 months.
Request To Include Reporting Requirement
The same commenter states that, if the AD is revised as proposed in
the first supplemental NPRM, the only way to properly evaluate the
effectiveness of the proposed corrective action is to require an FDR
readout and evaluation every 6 months for 2 years, and to submit the
results to the FAA for evaluation (as prescribed in the original NPRM).
The commenter further asserts that removal of the reporting requirement
will eliminate the opportunity for a fleet wide evaluation of the
continuing problem.
From these statements, we infer that the commenter is requesting
that we revise the first supplemental NPRM to again require operators
to report results of their calibration tests of the potentiometers and
the readouts of the FDR to us every 6 months for 2 years. We partially
agree with the commenter's request. As we explained previously, we have
reduced the compliance time for the repetitive interval for the
calibration tests of the potentiometers and the readouts of the FDR
from 12 months to 6 months. We also agree that the calibration testing
and readout results will be valuable for determining whether the
proposed corrective actions adequately address the noisy signals, loose
couplers, and incorrect calibrations that are found, and for
determining the extent of these in the affected fleet. Based on the
results of these reports, we may determine that further corrective
action is warranted. Therefore, we have revised this second
supplemental NPRM to add new a paragraph (f) that would require
operators to report results of the initial and repetitive calibration
tests of the potentiometers and the readouts of the FDR at intervals
not to exceed 6 months for 24 months, and reidentified subsequent
paragraphs accordingly.
However, we do not agree that these results should be submitted to
the FAA. The airplane manufacturer, EMBRAER, continually monitors the
effectiveness of corrective actions and reviews both the corrective
actions and their effectiveness with the Centro Technico Aeroespacial
(CTA), which is a division of the airworthiness authority for Brazil,
during quarterly service difficulty reviews. Therefore, we have
determined that the calibration testing and readouts of the FDR should
be reported directly to EMBRAER. We will work closely with EMBRAER and
the CTA to monitor the effectiveness of the corrective actions
specified in this second supplemental NPRM and will determine if
further corrective action is warranted based on the results of these
reports. No additional change to the second supplemental NPRM is
necessary in this regard.
Request To Revise the Method of Compliance
The same commenter requests that the first supplemental NPRM be
revised to include requirements to conduct the FDR readout and
evaluation just before the airplane's scheduled maintenance, with
emphasis on observing parameter performance during in-flight and ground
operations. The commenter further suggests that the most direct way to
detect a sensor failure or out-of-calibration condition would be for a
qualified analyst to periodically evaluate the FDR data, conduct a
calibration check, and make any necessary sensor replacements during
scheduled maintenance. The commenter asserts that the fact that one or
more flight control parameters failed in 16 of 17 Model EMB-120 FDR
readouts since 1990 suggests that the problem may be systemic and may
require a more robust sensor and/or installation. Further, the
commenter expresses doubt that all of the failures were caused by
storing the sensors for more than 12 months, which the airplane and
sensor manufacturers claim caused an oxide film to form on the sensor,
resulting in the noisy signals. The commenter supplied no data to
support this request.
We do not agree with the commenter's request to revise the
compliance method. However, as we explained previously, we have reduced
the compliance time for the repetitive interval for calibration testing
of the potentiometers and readout of the FDR. We find that installation
problems with the sensor's compatibility with the installation
environment would more likely appear as (hard) sensor failures, not
signal quality problems. The commenter itself points out that noisy
signals are rare and most service problems are related to poor
maintenance or an improperly executed FD replacement. Therefore,
because the potentiometers are sealed and require no maintenance, we
still consider oxide coating inside the potentiometers a contributing
factor to the source of the noisy signals--most likely a result of
prolonged disuse of the sensors. Therefore, we find that these proposed
corrective actions will purge any faulty sensors and that no change to
the second supplemental NPRM is necessary in this regard.
Clarification of Certain Terms
We have added a new Note 1 to this second supplemental NPRM (and
re-numbered subsequent notes accordingly) to clarify our use of the
word ``calibration.'' For the purposes of this second supplemental
NPRM, we define calibration as the adjustment of the potentiometers,
including operational and functional tests of the FDR system, as
specified in Section 31-30-00 of the EMBRAER EMB120 Airplane
Maintenance Manual (AMM).
Paragraph (a) of this second supplemental NPRM provides procedures
for a noise ``check'' to detect potentiometers with noisy signals. We
have determined that certified
[[Page 5072]]
maintenance personnel must perform the noise check.
Explanation of Additional Changes to the Second Supplemental NPRM
We have added a new paragraph (e) to this second supplemental NPRM
(and reidentified subsequent paragraphs accordingly) to state that
modification of the flexible couplings done before the effective date
of this AD in accordance with Change 01 of EMBRAER Service Bulletin
120-31-0038, dated October 3, 1997, is considered acceptable for
compliance with the corresponding action required by paragraph (d) of
this second supplemental NPRM.
We have also changed paragraphs (a) and (c) of this second
supplemental NPRM to specify that the proposed actions shall be done in
accordance with a method approved by the Manager, International Branch,
ANM-116, Transport Airplane Directorate, FAA. In addition, the
following sections of the EMBRAER EMB-120 AMM are identified as
approved methods of compliance for accomplishing the proposed actions
specified in the applicable paragraphs:
Paragraph (a): Section 31-30-00, dated April 10, 2002.
Paragraph (c): Section 31-30-05, dated July 17, 1998.
Additionally, we have added a new Note 2 to this second
supplemental NPRM (and re-numbered subsequent notes accordingly) to
clarify that Section 31-30-05 of the EMBRAER EMB120 AMM includes
instructions for calibrating the potentiometers (adjusting the
potentiometers, including operational and functional tests of the FDR
system). The procedures for that calibration are specified in Section
31-30-00 of the EMBRAER EMB120 AMM.
Conclusion
Since some of these changes expand the scope of the first
supplemental NPRM, the FAA has determined that it is necessary to
reopen the comment period to provide additional opportunity for public
comment.
Changes to 14 CFR part 39/Effect on the Proposed AD
On July 10, 2002, the FAA issued a new version of 14 CFR part 39
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness
directives system. The regulation now includes material that relates to
altered products, special flight permits, and alternative methods of
compliance (AMOC). Because we have now included this material in part
39, only the office authorized to approve AMOCs is identified in each
individual AD. Therefore, paragraph (g) has been revised and paragraph
(h) and Notes 1 and 4 of the first supplemental NPRM have been removed
from this supplemental NPRM.
Increase in Labor Rate
After the first supplemental NPRM was issued, we reviewed the
figures we use to calculate the labor rate to do the required actions.
To account for various inflationary costs in the airline industry, we
find it appropriate to increase the labor rate used in these
calculations from $60 per work hour to $65 per work hour. The economic
impact information, below, has been revised to reflect this increase in
the specified hourly labor rate.
Cost Impact
The FAA estimates that 587 airplanes of U.S. registry would be
affected by this proposed AD. The following table provides the
estimated costs for U.S. operators to comply with this proposed AD.
Estimated Costs
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Average
labor Cost of parts per
Action Work hours rate per airplane Cost per airplane
hour
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Calibration and FDR readout, per 1 per potentiometer $65 Negligible.......... $65, potentiometer
calibration cycle (3 (for digital-type (for digital-
potentiometers per airplane). FDRs), per calibration type
calibration cycle; FDRs), per
or 25 per calibration cycle;
potentiometer (for or $1,625, per
tape-type FDRs), per potentiometer (for
calibration cycle. tape-type FDRs),
per calibration
cycle.
Application of adhesive........... 1.................... 65 Negligible.......... $65.
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The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the proposed 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.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, Section 106, describes the
authority of the FAA Administrator. Subtitle VII, Aviation Programs,
describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701, ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
We have determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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.
For the reasons discussed above, I certify that the proposed
regulation:
1. Is not a ``significant regulatory action'' under Executive Order
12866;
2. Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979); and
3. Will not have a significant economic impact, positive or
negative, on a substantial number of small entities
[[Page 5073]]
under the criteria of the Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to
comply with this proposed AD. See the ADDRESSES section for a location
to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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), certificated in
any category, that are required by 14 CFR 135 to operate with a
flight data recorder (FDR).
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 Potentiometer Calibration Testing and FDR Readout
(a) Within 6 months after the effective date of this AD:
Calibrate 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 a method approved by the Manager,
International Branch, ANM-116, Transport Airplane Directorate, FAA.
Section 31-30-00, dated April 10, 2002, of the EMBRAER EMB-120
Airplane Maintenance Manual (AMM) is one approved method. The noise
check must be performed by certificated maintenance personnel.
Note 1: For the purposes of this AD, calibration is defined as
the adjustment of the potentiometers, including operational and
functional tests of the FDR system, as specified in Section 31-30-00
of the EMBRAER EMB120 AMM.
Repetitive Potentiometer Calibration Testing and FDR Readout
(b) Repeat the calibration and 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 6 months.
Replacement of Potentiometers
(c) If any readout of the FDR, conducted in accordance with
paragraph (a) or (b) of this AD, indicates a potentiometer with a
noisy signal: Within 20 days after obtaining the readout, replace
the potentiometer with one that has a date of manufacture no greater
than 12 months from the date of installation, in accordance with a
method approved by the Manager, International Branch, ANM-116,
Transport Airplane Directorate, FAA. Section 31-30-05, dated July
17, 1998, of the EMBRAER EMB-120 AMM is one approved method.
Note 2: Section 31-30-05 of the EMBRAER EMB120 AMM includes
instructions for calibrating the potentiometers. The procedures for
the calibration are specified in Section 31-30-00 of the EMB120 AMM.
Modification of Flexible Couplers
(d) Prior to further flight, after accomplishing 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, dated February
22, 1997; or Change 02, dated June 25, 1998.
Modification Accomplished Per Previous Issue of Service Bulletin
(e) Modification of the flexible couplers done before the
effective date of this AD in accordance with EMBRAER Service
Bulletin 120-31-0038, Change 01, dated October 3, 1997, is
considered acceptable for compliance with the corresponding action
specified in paragraph (d) of this AD.
Reporting Requirement
(f) At the applicable time specified in paragraph (f)(1) or
(f)(2) of this AD: Submit a report of the calibration tests of the
potentiometers and the readouts of the FDR to Empresa Brasileira de
Aeronautica S.A. (EMBRAER), Certification--Continued Airworthiness,
Av. Brig. Faria Lima, 2170, P.C. 179, 12227-901, Sao Jose dos
Campos--SP, Brazil; fax (12) 3927-1184. 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 calibration tests, noise checks, and FDR readouts done
after the effective date of this AD: Submit the report within 30
days after performing each test, check, and readout required by
paragraphs (a) and (b) of this AD.
(2) For calibration tests, noise checks, and FDR readouts done
before to the effective date of this AD: Submit the report within 10
days after the effective date of this AD.
Alternative Methods of Compliance
(g) In accordance with 14 CFR 39.19, the Manager, International
Branch, ANM-116, Transport Airplane Directorate, FAA, is authorized
to approve alternative methods of compliance for this AD.
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 January 21, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-1795 Filed 1-31-05; 8:45 am]
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