[Federal Register: November 19, 2004 (Volume 69, Number 223)]
[Rules and Regulations]
[Page 67636-67638]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19no04-2]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE213; Special Conditions No. 23-152-SC]
Special Conditions: Thielert Aircraft Engines; Cessna Model 172
K, L, M, N, P, R, and S Series Airplanes; Installation of Thielert TAE-
125-01 Aircraft Diesel Engine for Full Authority Digital Engine Control
(FADEC) System and the Protection of the System From the Effects of
High Intensity Radiated Fields (HIRF)
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued to Thielert Aircraft
Engines, GmbH, Lichtenstein, Germany for a supplemental type
certificate for the Cessna Model 172 series airplanes. The supplemental
type certificate for these airplanes will have a novel or unusual
design feature associated with the installation of an aircraft diesel
engine that uses an electronic engine control system instead of a
mechanical control system. The applicable airworthiness regulations do
not contain adequate or appropriate safety standards for this design
feature. These special conditions contain the additional safety
standards that the Administrator considers necessary to establish a
level of safety equivalent to that established by the existing
airworthiness standards.
DATES: The effective date of these special conditions is: November 1,
2004. Comments must be received on or before December 20, 2004.
ADDRESSES: Comments on this proposal may be mailed in duplicate to:
Federal Aviation Administration (FAA), Regional Counsel, ACE-7,
Attention: Rules Docket, Docket No. CE213, 901 Locust, Room 506, Kansas
City, Missouri 64106, or delivered in duplicate to the Regional Counsel
at the above address. Comments must be marked: Docket No. CE213.
Comments may be inspected in the Rules Docket weekdays, except Federal
holidays, between 7:30 a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT: Pete Rouse, Federal Aviation
Administration, Aircraft Certification Service, Small Airplane
Directorate, ACE-111, 901 Locust, Room 301, Kansas City, Missouri
64106; telephone: (816) 329-4135, fax: (816) 329-4090.
SUPPLEMENTARY INFORMATION: The FAA has determined that notice and
opportunity for prior public comment hereon are impracticable because
these procedures would significantly delay issuance of the design
approval and thus delivery of the affected aircraft. In addition, the
substance of these special conditions has been subject to the public
comment process in several prior instances with no substantive comments
received. The FAA, therefore, finds that good cause exists for making
these special conditions effective upon issuance.
Comments Invited
Interested persons are invited to submit such written data, views,
or arguments as they may desire. Communications should identify the
regulatory docket or special condition number and be submitted in
duplicate to the address specified above. All communications received
on or before the closing date for comments will be considered by the
Administrator. The special conditions may be changed in light of the
comments received. All comments received will be available in the Rules
Docket for examination by interested persons, both before and after the
closing date for comments. A report summarizing each substantive public
contact with FAA personnel concerning this rulemaking will be filed in
the docket. Commenters wishing the FAA to acknowledge receipt of their
comments submitted in response to this notice must include a self-
addressed, stamped postcard on which the following statement is made:
``Comments to Docket No. CE213.'' The postcard will be date stamped and
returned to the commenter.
Background
On February 11, 2002, Thielert Aircraft Engines applied for a
supplemental type certificate for the Cessna Model 172 series
airplanes. The supplemental type certificate will allow Thielert
Aircraft Engines to install a Thielert Aircraft engine (TAE 125-01
aircraft diesel engine (ADE)) that is equipped with an electronic
engine control system with full authority capability in these
airplanes.
Type Certification Basis
Under the provisions of 14 CFR, part 21, Sec. 21.101, Thielert
Aircraft Engines must show that the Cessna Model 172 meets the
applicable provisions of the original certification basis of the Cessna
Model 172, as listed on Type Certificate No. 3A12, issued on November
4, 1955; exemptions, if any; and the special conditions adopted by this
rulemaking action. The Cessna Model 172 was originally certified under
part 3 of the Civil Air Regulations.
If the Administrator finds that the applicable airworthiness
regulations (i.e., CAR 3; 14 CFR, part 23) do not contain adequate or
appropriate safety standards for the Cessna 172 because of a novel or
unusual design feature, special conditions are prescribed under the
provisions of Sec. 21.16.
Special conditions, as appropriate, as defined in Sec. 11.19, are
issued in accordance with Sec. 11.38, and become part of the
certification basis for the supplemental type certification basis in
accordance with Sec. 21.101. Special conditions are initially
applicable to the model for which they are issued. Should the applicant
apply for a supplemental type certificate to modify any other models
that are listed on the same type certificate to incorporate the same
novel or unusual design features, the special conditions would also
apply under the provisions of Sec. 21.101.
Novel or Unusual Design Features
The Thielert Aircraft Engines modified Cessna Model 172 will
incorporate a novel or unusual design feature, an engine that includes
an electronic control system with full authority digital engine control
(FADEC) capability.
Many advanced electronic systems are prone to either upsets or
damage, or both, at energy levels lower than analog systems. The
increasing use of high power radio frequency emitters mandates
requirements for improved high intensity radiated fields (HIRF)
protection for electrical and electronic equipment. Since the
electronic engine control system used on the Thielert
[[Page 67637]]
Aircraft Engines modified Cessna Model 172 will perform critical
functions, provisions for protection from the effects of HIRF should be
considered and, if necessary, incorporated into the airplane design
data. The FAA policy contained in Notice 8110.71, dated April 2, 1998,
establishes the HIRF energy levels that airplanes will be exposed to in
service. The guidelines set forth in this notice are the result of an
Aircraft Certification Service review of existing policy on HIRF, in
light of the ongoing work of the Aviation Rulemaking Advisory Committee
(ARAC) Electromagnetic Effects Harmonization Working Group (EEHWG). The
EEHWG adopted a set of HIRF environment levels in November 1997 that
were agreed upon by the FAA, the Joint Aviation Authorities (JAA), and
industry participants. As a result, the HIRF environments in this
notice reflect the environment levels recommended by this working
group. This notice states that a FADEC is an example of a system that
should address the HIRF environments.
Even though the control system will be certificated as part of the
engine, the installation of an engine with an electronic control system
requires evaluation due to the possible effects on or by other airplane
systems (e.g., radio interference with other airplane electronic
systems, shared engine and airplane power sources). The regulatory
requirements in 14 CFR, part 23 for evaluating the installation of
complex systems, including electronic systems, are contained in Sec.
23.1309. However, when Sec. 23.1309 was developed, the use of
electronic control systems for engines was not envisioned; therefore,
the Sec. 23.1309 requirements were not applicable to systems
certificated as part of the engine (reference Sec. 23.1309(f)(1)).
Also, electronic control systems often require inputs from airplane
data and power sources and outputs to other airplane systems (e.g.,
automated cockpit powerplant controls such as mixture setting).
Although the parts of the system that are not certificated with the
engine could be evaluated using the criteria of Sec. 23.1309, the
integral nature of systems such as these makes it unfeasible to
evaluate the airplane portion of the system without including the
engine portion of the system. However, Sec. 23.1309(f)(1) again
prevents complete evaluation of the installed airplane system since
evaluation of the engine system's effects is not required.
Therefore, special conditions are proposed for the Thielert
Aircraft Engines modified Cessna Model 172 airplane to provide HIRF
protection and to evaluate the installation of the electronic engine
control system for compliance with the requirements of Sec. 23.1309(a)
through (e) at Amendment 23-49.
Applicability
As discussed above, these special conditions are applicable to the
Thielert Aircraft Engines modified Cessna Model 172. Should Thielert
Aircraft Engines apply at a later date for a supplemental type
certificate to modify any other model included on the same type
certificate as the Thielert Aircraft Engines modified Cessna Model 172
to incorporate the same novel or unusual design features, the special
conditions would apply to that model as well under the provisions of
Sec. 21.101.
Conclusion
This action affects only certain novel or unusual design features
on one model, the Cessna Model 172 K, L, M, N, P, R, and S series
airplanes. It is not a rule of general applicability, and it affects
only the applicant who applied to the FAA for approval of these
features on the airplane.
Under standard practice, the effective date of final special
conditions would be 30 days after the date of publication in the
Federal Register. However the FAA finds that good cause exists to make
these special conditions effective upon issuance.
List of Subjects in 14 CFR Part 23
Aircraft, Aviation safety, Signs and symbols.
Citation
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113 and 44701; 14 CFR 21.16 and
21.101; and 14 CFR 11.38 and 11.19.
The Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the supplemental type certification basis for Thielert Aircraft Engines
modified Cessna Model 172 airplanes.
1. High Intensity Radiated Fields (HIRF) Protection. In showing
compliance with 14 CFR part 21 and the airworthiness requirements of 14
CFR part 23, protection against hazards caused by exposure to HIRF
fields for the full authority digital engine control system, which
performs critical functions, must be considered. To prevent this
occurrence, the electronic engine control system must be designed and
installed to ensure that the operation and operational capabilities of
this critical system are not adversely affected when the airplane is
exposed to high energy radio fields.
At this time, the FAA and other airworthiness authorities are
unable to precisely define or control the HIRF energy level to which
the airplane will be exposed in service; therefore, the FAA hereby
defines two acceptable interim methods for complying with the
requirement for protection of systems that perform critical functions.
(1) The applicant may demonstrate that the operation and
operational capability of the installed electrical and electronic
systems that perform critical functions are not adversely affected when
the aircraft is exposed to the external HIRF threat environment defined
in the following table:
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Field strength (volts per meter)
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Frequency Peak Average
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10 kHz-100 kHz...................................... 50 50
100 kHz-500 kHz..................................... 50 50
500 kHz-2 MHz....................................... 50 50
2 MHz-30 MHz........................................ 100 100
30 MHz-70 MHz....................................... 50 50
70 MHz-100 MHz...................................... 50 50
100 MHz-200 MHz..................................... 100 100
200 MHz-400 MHz..................................... 100 100
400 MHz-700 MHz..................................... 700 50
700 MHz-1 GHz....................................... 700 100
1 GHz-2GHz.......................................... 2000 200
2 GHz-4 GHz......................................... 3000 200
4 GHz-6 GHz......................................... 3000 200
6 GHz-8 GHz......................................... 1000 200
8 GHz-12 GHz........................................ 3000 300
12 GHz-18 GHz....................................... 2000 200
18 GHz-40 GHz....................................... 600 200
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The field strengths are expressed in terms of peak root-mean-square
(rms) values.
or,
(2) The applicant may demonstrate by a system test and analysis
that the electrical and electronic systems that perform critical
functions can withstand a minimum threat of 100 volts per meter peak
electrical strength, without the benefit of airplane structural
shielding, in the frequency range of 10 KHz to 18 GHz. When using this
test to show compliance with the HIRF requirements, no credit is given
for signal attenuation due to installation. Data used for engine
certification may be used, when appropriate, for airplane
certification.
2. Electronic Engine Control System. The installation of the
electronic engine control system must comply with the requirements of
Sec. 23.1309(a) through (e) at Amendment 23-49. The intent of this
requirement is not to re-evaluate the inherent hardware reliability of
the control itself, but rather determine the effects, including
environmental effects
[[Page 67638]]
addressed in Sec. 23.1309(e), on the airplane systems and engine
control system when installing the control on the airplane. When
appropriate, engine certification data may be used when showing
compliance with this requirement.
Issued in Kansas City, Missouri, on November 1, 2004.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-25698 Filed 11-18-04; 8:45 am]
BILLING CODE 4910-13-P