[Federal Register: November 22, 2004 (Volume 69, Number 224)]
[Proposed Rules]
[Page 67860-67864]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22no04-21]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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[[Page 67860]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE214; Notice No. 23-04-02-SC]
Special Conditions: Thielert Aircraft Engines GmbH, Cessna Model
172 Series; Diesel Cycle Engine Using Turbine (Jet) Fuel
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
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SUMMARY: This proposes special conditions for the Cessna 172 series
airplane. This airplane, as modified by Thielert Aircraft Engines GmbH,
will have a novel or unusual design feature(s) associated with the
installation of a diesel cycle engine utilizing turbine (jet) fuel. The
applicable airworthiness regulations do not contain adequate or
appropriate safety standards for installation of this new technology
engine. These proposed special conditions contain the additional safety
standards that the Administrator considers necessary to establish a
level of safety equivalent to that established by the exiting
airworthiness standards.
DATES: Comments must be received on or before December 22, 2004.
ADDRESSES: Comments on this proposal may be mailed in duplicate to:
Federal Aviation Administration, Regional Counsel, ACE-7, Attention:
Rules Docket, Docket No. CE214, 901 Locust, Room 506, Kansas City,
Missouri 64106, or delivered in duplicate to the Regional Counsel at
the above address. Comments must be marked: CE214. 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, Kansas City, Missouri, 816-329-4135,
fax 816-329-4090.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of
these proposed special conditions by submitting such written data,
views, or arguments, as they may desire. Communications should identify
the regulatory docket or notice 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 proposals described in this notice 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. Persons wishing the FAA to acknowledge receipt of their
comments submitted in response to this notice must include with those
comments a self-addressed, stamped postcard on which the following
statement is made: ``Comments to CE214.'' The postcard will be date
stamped and returned to the commenter.
Background
On February 11, 2002, Thielert Aircraft Engines GmbH, of
Lichtenstein, Germany applied for a supplemental type certificate to
install a diesel cycle engine utilizing turbine (jet) fuel in the
Cessna Model 172. The Cessna Model 172, currently approved under Type
Certificate No. 3A12 is a four-place, high wing, fixed tricycle landing
gear, conventional planform airplane. The Cessna 172 airplanes to be
modified have gross weights in the range of 2300 to 2558 pounds in the
normal category. The affected series of airplanes have been equipped
with various gasoline reciprocating engines of 160 to 180 horsepower.
In anticipation of the reintroduction of diesel engine technology
into the small airplane fleet, the FAA issued Policy Statement PS-
ACE100-2002-004 on May 15, 2003, which identified areas of
technological concern involving introduction of new technology diesel
engines into small airplanes. For a more detailed summary of the FAA's
development of diesel engine requirements, refer to this policy.
The general areas of concern involved the power characteristics of
the diesel engines, the use of turbine fuel in an airplane class that
has typically been powered by gasoline fueled engines, the vibration
characteristics and failure modes of diesel engines. These concerns
were identified after review of the historical record of diesel engine
use in aircraft and a review of the 14 CFR part 23 regulations, which
identified specific regulatory areas that needed to be elevated for
applicability to diesel engine installations. These concerns are not
considered universally aplicable to all types of possible diesel
engines and diesel engine installations. However, after review of the
Thielert installation, the Thielert engine type, and the requirements
applied by the Lufthart Bundesamt, and applying the provisions of the
diesel policy, the FAA proposed these fuel system and engine related
special conditions. Other special conditions issued in a separate
notice included special conditions for HIRF and application of Sec.
23.1309 provisions to the Full Authority Digital Engine Control
(FADEC).
Type Certification Basis
Under the provisions of Sec. 21.101, Thielert Aircraft Engines
GmbH must show that the Cessna Model 172, as changed, continues to meet
the applicable provisions of the regulations incorporated by reference
in Type Certificate No. 3A13 or the applicable regulations in effect on
the date of application for the change. The regulations incorporated by
reference in the type certificate are commonly referred to as the
``original type certification basis.'' The regulations incorporated by
reference in Type Certificate No. 3A13 are as follows:
The certification basis of models 172K, 172L, 172M, 172N, and 172P
is:
Part 3 of the Civil Air Regulations effective November 1, 1949, as
amended by 3-1 through 3-12. In addition, effective S/N 17271035 and
on, 14 CFR part 23, Sec. 23.1559, effective March 1, 1978. 14 CFR part
36, dated December 1, 1969, plus Amendments 36-1 through 36-5 for Model
172N; 14 CFR part 36, dated December 1, 1969, plus Amendments 36-1
through 36-12 for Model 172P through 172Q. In addition, effective S/N
17276260 and on, 14 CFR
[[Page 67861]]
part 23, Sec. 23.1545(a), Amendment 23-23, dated December 1, 1978,
including:
Equivalent Safety Items for:
Airspeed Indicator--CAR 3.757
Operating Limitations--CAR 3.778(a)
The certification basis for the model 172R is:
Part 23 of the Federal Aviation Regulations effective February 1,
1965, as amended by 23-1 through 23-6, eccept as follows:
14 CFR part 23, Sec. Sec. 23.423; 23.611; 23.619; 23.623; 23.689;
23.775; 23.871; 23.1323; and 23.1563, as amended by Amendment 23-7. 14
CFR part 23, Sec. Sec. 23.807 and 23.1524, as amended by Amendment 23-
10. 14 CFR part 23, Sec. Sec. 23.507; 23.771; 23.853(a), (b) and (c);
and 23.1365, as amended by Amendment 23-14. 14 CFR part 23, Sec.
23.951, as amended by Amendment 23-15. 14 CFR part 23, Sec. Sec.
23.607; 23.675; 23.685; 23.733; 23.787; 23.1309 and 23.1322, as amended
by Amendment 23-17. 14 CFR part 23, Sec. 23.1301, as amended by
Amendment 23-20. 14 CFR part 23, Sec. Sec. 23.1353; and 23.1559, as
amended by Amendment 23-21. 14 CFR part 23, Sec. Sec. 23.603; 23.605;
23.613; 23.1329 and 23.1545, as amended by Amendment 23-23. 14 CFR part
23, Sec. Sec. 23.441 and 23.1549, as amended by Amendment 23-28. 14
CFR part 23, Sec. Sec. 23.779 and 23.781, as amended by Amendment 23-
33. 14 CFR part 23, Sec. Sec. 23.1; 23.51 and 23.561, as amended by
Amendment 23-34. 14 CFR part 23, Sec. Sec. 23.301; 23.331; 23.351;
23.427; 23.677; 23.701; 23.735; and 23.831, as amended by Amendment 23-
42. 14 CFR part 23, Sec. Sec. 23.961; 23.1093; 23.1143(g); 23.1147(b);
23.1303; 23.1357; 23.1361 and 23.1385, as amended by Amendment 23-43.
14 CFR part 23.562(a), 23.562(b)2, 23.562(c)1, 23.562(c)2, 23.562(c)3,
and 23.562(c)4, as amended by Amendment 23-44. 14 CFR part 23,
Sec. Sec. 23.33; 23.53; 23.305; 23.321; 23.485; 23.621; 23.655 and
23.731, as amended by Amendment 23-45; and 14 CFR part 36, dated
December 1, 1969, as amended by Amendments 36-1 through 36-21.
Equivalent Safety Items for:
Induction System Icing Protection--14 CFR 23.1093
Throttle Control--14 CFR 23.1143(g)
Mixture Control--14 CFR 23.1147(b)
The type certification basis for the modified airplanes is as
stated previously with the following modifications: The certification
basis for the model 172S is:
Part 23 of the Federal Aviation Regulations effective February 1,
1965, as amended by 23-1 through 23-6, except as follows:
14 CFR part 23, Sec. Sec. 23.423; 23.611; 23.619; 23.623; 23.689;
23.775; 23.871; 23.1323; and 23.1563, as amended by Amendment 23-7. 14
CFR part 23, Sec. Sec. 23.807 and 23.1524, as amended by Amendment 23-
10. 14 CFR part 23, Sec. Sec. 23.507; 23.771; 23.853(a), (b) and (c);
and 23.1365, as amended by Amendment 23-14. 14 CFR part 23, Sec.
23.951, as amended by Amendment 23-15. 14 CFR part 23, Sec. Sec.
23.607; 23.675; 23.685; 23.733; 23.787; 23.1309 and 23.1322, as amended
by Amendment 23-17. 14 CFR part 23, Sec. 23.1301, as amended by
Amendment 23-20. 14 CFR part 23, Sec. Sec. 23.1353 and 23.1559, as
amended by Amendment 23-21. 14 CFR part 23, Sec. Sec. 23.603; 23.605;
23.613; 23.1329 and 23.1545, as amended by Amendment 23-23. 14 CFR part
23, Sec. Sec. 23.441 and 23.1549, as amended by Amendment 23-28. 14
CFR part 23, Sec. Sec. 23.779 and 23.781, as amended by Amendment 23-
33. 14 CFR part Sec. Sec. 23.1; 23.51 and 23.561, as amended by
Amendment 23-34. 14 CFR part 23, Sec. Sec. 23.301; 23.331; 23.351;
23.427; 23.677; 23.701; 23.735; and 23.831, as amended by Amendment 23-
42. 14 CFR part 23, Sec. Sec. 23.961; 23.1093; 23.1143(g); 23.1147(b);
23.1303; 23.1357; 23.1361 and 23.1385, as amended by Amendment 23-43.
14 CFR part 23, Sec. Sec. 23.562(a); 23.562(b)2; 23.562(c)1;
23.562(c)2; 23.562(c)3; and 23.562(c)4, as amended by Amendment 23-42.
14 CFR part 23, Sec. Sec. 23.961; 23.1093; 23.1143(g); 23.1147(b);
23.1303; 23.1357; 23.1361 and 23.1385, as amended by Amendment 23-43.
14 CFR part 23, Sec. Sec. 23.562(a); 23.562(b)2; 23.562(c)1;
23.562(c)2; 23.562(c)3; and 23.562(c)4, as amended by Amendment 23-44.
14 CFR part 23, Sec. Sec. 23.33; 23.53; 23.305; 23.321; 23.485;
23.621; 23.655 and 23.731, as amended by Amendment 23-45.
14 CFR part 36, dated December 1, 1969, as amended by Amendments
36-1 through 36-21.
Equivalent Safety Items for:
Induction System Icing Protection--14 CFR 23.1093
Throttle Control--14 CFR 23.1143(g)
Mixture Control--14 CFR 23.1147(b)
14 CFR part 23, at Amendment level 23-51, applicable to the areas
of change:
14 CFR part 23, Sec. Sec. 23.1; 23.3; 23.21; 23.23; 23.25; 23.29;
23.33; 23.45; 23.49; 23.51; 23.53; 23.63; 23.65; 23.69; 23.71; 23.73;
23.77; 23.141; 23.143; 23.145; 23.151; 23.153; 23.155; 23.171; 23.173;
23.175; 23.177; 23.201; 23.221; 23.231; 23.251; 23.301; 23.303; 23.305;
23.307; 23.321; 23.335; 23.337; 23.341; 23.343; 23.361; 23.363; 23.371;
23.572; 23.573; 23.574; 23.601; 23.603; 23.605; 23.607; 23.609; 23.611;
23.613; 23.619; 23.621; 23.623; 23.625; 23.627; 23.629; (at Amendment
23-6 for Cessna 172 models R and S; Civil Aviation Regulation 3.159
applies to all other models); 23.773; 23.777; 23.777(d); 23.779;
23.779(d); 23.781; 23.831; 23.863; 23.865; 23.867; 23.901;
23.901(d)(1); 23.903; 23.905; 23.907; 23.909; 23.925; 23.929; 23.939;
23.943; 23.951; 23.951(c); 23.954; 23.955; 23.959; 23.961; 23.963;
23.965; 23.967; 23.969; 23.971; 23.973; 23.973(f); 23.975; 23.977;
23.991; 23.993; 23.994; 23.995; 23.997; 23.997(a)(2), in place of
Sec. Sec. 23.997(a)(1); 23.999; 23.1011; 23.1013; 23.1015; 23.1017;
23.1019; 23.1021; 23.1023; 23.1041; 23.1043; 23.1047; 23.1061; 23.1063;
23.1091; 23.1093; 23.1103; 23.1107; 23.1121; 23.1123; 23.1141; 23.1143;
23.1145; 23.1163; 23.1165; 23.1181; 23.1182; 23.1183; 23.1191; 23.1193;
23.1301; 23.1305; 23.1309; 23.1311; 23.1321; 23.1322; 23.1327; 23.1331;
23.1337; 23.1351; 23.1353; 23.1357; 23.1359; 23.1361; 23.1365; 23.1367;
23.1381; 23.1431; 23.1461; 23.1501; 23.1519; 23.1521; 23.1527; 23.1529;
23.1541; 23.1543; 23.1549; 23.1551; 23.1555; 23.1557; 23.1567; 23.1581;
23.1583; 23.1585; 23.1587; and 23.1589.
Equivalent levels of safety for:
Cockpit controls--23.777(d)
Motion and effect of cockpit controls--23.779(b)
Liquid Cooling--23.1061
Ignition switches--23.1145
The type certification basis includes exemption, if any; equivalent
level of safety findings, if any; and the special conditions adopted by
this rulemaking action.
In addition, if the regulations incorporated by reference do not
provide adequate standards with respect to the change, the applicant
must comply with certain regulations in effect on the date of
application for the change. The type certification basis for the
modified airplanes is as stated previously with the following
modifications:
If the Administrator finds that the applicable airworthiness
regulations (i.e., part 23) do not contain adequate or appropriate
safety standards for the Cessna Model 172 because of a novel or unusual
design feature, special conditions are prescribed under the provisions
of Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the Cessna Model 172 must comply with the part 23 noise
certification requirements of 14 CFR part 36.
Special conditions, as appropriate, as defined in Sec. 11.19, are
issued in
[[Page 67862]]
accordance with Sec. 11.38, and become part of the 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 model included on the same type
certificate to incorporate the same novel or unusual design feature,
the special conditions would also apply to the other model under the
provisions of Sec. 21.101.
Novel or Unusual Design Features
The Cessna Model 172 will incorporate the following novel or
unusual design features: The Cessna Model 172, as modified by Thielert
Aircraft Engines GmbH, will incorporate an aircraft diesel engine
utilizing turbine (jet) fuel.
Applicability
As dicussed above, these special conditions are applicable to the
Cessna Model 172. Should Thielert Aircraft Engines GmbH apply at a
later date for a supplemental type certificate to modify any other
model included on Type Certificate No. 3A13 to incorporate the same
novel or unusual design feature, 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 series of airplane. 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.
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.
Discussion
The major concerns identified in the development of FAA policy deal
with the installation of the diesel engine and its vibration levels
under normal operating conditions and with one cylinder inoperative,
the accommodation of turbine fuels in airplane systems that have
generally evolved based on gasoline requirements, the anticipated use
of a FADEC to control the engine, and the appropriate limitations and
indications for a diesel engine powered airplane. The general concerns
associated with the Thielert modification are as follows:
Installation and Vibration Requirements
Fuel and Fuel System Related Requirements
FADEC and Electrical System Requirements
Limitations and Indications
Installation and Vibration Requirements: These special conditions
include requirements similar to the requirements of Sec. 23.901(d)(1)
for turbine engines. In addition to the requirements of Sec. 23.901
applied to reciprocating engines, the applicant will be required to
construct and arrange each diesel engine installation to result in
vibration characteristics that do not exceed those established during
the type certification of the engine; and do not exceed vibration
characteristics that a previously certificated airframe structure has
been approved for, unless such vibration characteristics are shown to
have no effect on safety or continued airworthiness. The engine limit
torque design requirements as specified in Sec. 23.361 are also
modified.
An additional requirement to consider vibration levels and/or
effects of an inoperative cylinder was imposed. Also, a requirement to
evaluate the engine design for the possibility of, or effect of,
liberating high-energy engine fragments, in the event of a catastrophic
engine failure, was added.
Fuel and Fuel System Related Requirements: Due to the use of
turbine fuel, this airplane must comply with the requirements in Sec.
23.951(c).
Section 23.961 will be complied with using the turbine fuel
requirements. These requirements will be substantiated by flight-
testing as described in Advisory Circular AC 23-8B, Flight Test Guide
for Certification of Part 23 Airplanes.
This special condition specifically requires testing to show
compliance to Sec. 23.961 and adds the possibility of testing non-
aviation diesel fuels.
To ensure fuel system compatability and reduce the possibility of
misfueling, and discounting the first clause of Sec. 23.973(f)
referring to turbine engines, the applicant will comply with Sec.
23.973(f).
Due to the use of turbine fuel, the applicant will comply with
Sec. 23.977(a)(2), and Sec. 23.977(a)(1) will not apply. ``Turbine
engines'' will be interpreted to mean ``aircraft diesel engine'' for
this requirement. An additional requirement to consider the possibility
of fuel freezing was imposed.
Due to the use of turbine fuel, the applicant will comply with
Sec. 23.1305(c)(8).
Due to the use of turbine fuel, the applicant must comply with
Sec. 23.1557(c)(1)(ii). Section 23.1557(c)(1)(ii) will not apply.
``Turbine engine'' is interpreted to mean ``aircraft diesel engine''
for this requirement.
FADEC and Electrical System Requirements: The electrical system
must comply with the following:
In case of failure of one power supply of the electrical
system, there will be no significant engine power change. The
electrical power supply to the FADEC must remain stable in such a
failure.
The transition from the actual engine net (FADEC) to the
remaining electrical system with the consumer's avionics, communication
etc. should be made by a single point only. If several transitions
(e.g., for redundancy reasons) are needed, then the number of the
transitions must be kept as small as possible.
There must be the ability to separate the FADEC power
supply (alternator) from the battery and from the remaining electrical
system.
In case of loss of alternator power the installation must
guarantee that the battery will provide the power for an appropriate
time after appropriate warning to the pilot.
FADEC, alternator and battery must be interconnected in an
appropriate way, so that in case of loss of battery power, the supply
of the FADEC is guaranteed by the alternator.
Limitations and Indications: Section 23.1305(a) and Sec.
23.1305(b)(2) will apply, except that propeller revolutions per minute
(RPM) will be displayed. Sections 23.1305(b)(4), 23.1305(b)(5) and
23.1305(b)(7) are deleted. Additional critical engine parameters for
this installation that will be displayed include the following:
(1) Power setting, in percentage, and
(2) Fuel temperature.
Due to the use of turbine fuel, the requirements for Sec.
23.1521(d), as applicable to fuel designation for turbine engines, will
apply.
The Proposed Special Conditions
Accordingly, the Federal Aviation Administration (FAA) proposes the
following special conditions as part of the type certification basis
for Cessna Model 172 airplanes modified by Thielert Aircraft Engines
GmbH.
1. Engine Torque (Provisions Similar to Sec. 23.361, Paragraphs (b)(1)
and (c)(3))
(a) For diesel engine installations, the engine mounts and
supporting structure must be designed to withstand the following:
[[Page 67863]]
(1) A limit engine torque load imposed by sudden engine stoppage
due to malfunction or structural failure.
The effects of sudden engine stoppage may alternately be mitigated
to an acceptable level by utilization of isolators, dampers clutches
and similar provisions, so that unacceptable load levels are not
imposed on the previously certificated structure.
(b) The limit engine torque to be considered under paragraph 14 CFR
part 23, Sec. 23.361(a) must be obtained by multiplying the mean
torque by a factor of four for diesel cycle engines.
(1) If a factor of less than four is utilized, it must be shown
that the limit torque imposed on the engine mount is consistent with
the provisions of Sec. 23.361(c), that is, it must be shown that the
utilization of the factors listed in Sec. 23.361(c)(3) will result in
limit torques being imposed on the mount that are equivalent or less
than those imposed by a conventional gasoline reciprocating engine.
2. Powerplant--Installation (Provisions Similar to Sec. 23.901(d)(1)
for Turbine Engines)
Considering the vibration characteristics of diesel engines, the
applicant must comply with the following:
(a) Each diesel engine installation must be constructed and
arranged to result in vibration characteristics that--
(1) Do not exceed those established during the type certification
of the engine; and
(2) Do not exceed vibration characteristics that a previously
certificated airframe structure has been approved for--
(i) Unless such vibration characteristics are shown to have no
effect on safety or continued airworthiness, or
(ii) Unless mitigated to an acceptable level by utilization of
isolators, dampers clutches and similar provisions, so that
unacceptable vibration levels are not imposed on the previously
certificated structure.
3. Powerplant--Fuel System--Fuel System With Water Saturated Fuel
(Compliance With Sec. 23.951 requirements)
Considering the fuel types used by diesel engines, the applicant
must comply with the following:
Each fuel system for a diesel engine must be capable of sustained
operation throughout its flow and pressure range with fuel initially
saturated with water at 80 [deg]F and having 0.75cc of free water per
gallon added and cooled to the most critical condition for icing likely
to be encountered in operation.
Methods of compliance that are acceptable for turbine engine fuel
systems requirements of Sec. 23.951(c) are also considered acceptable
for this requirement.
4. Powerplant--Fuel System--Fuel System Hot Weather Operation
(Compliance With Sec. 23.961 Requirements)
In place of compliance with Sec. 23.961, the applicant must comply
with the following:
Each fuel system must be free from vapor lock when using fuel at
its critical temperature, with respect to vapor formation, when
operating the airplane in all critical operating and environmental
conditions for which approval is requested. For turbine fuel, or for
aircraft equipped with diesel cycle engines that use turbine or diesel
type fuels, the initial temperature must be 110 [deg]F, -0[deg],
+5[deg] or the maximum outside air temperature for which approval is
requested, whichever is more critical.
The fuel system must be in an operational configuration that will
yield the most adverse, that is, conservative results.
To comply with this requirement, the applicant must use the turbine
fuel requirements and must substantiate these by flight-testing, as
described in Advisory Circular AC 23-8B, Flight Test Guide for
Certification of Part 23 Airplanes.
5. Powerplant--Fuel System--Fuel Tank Filler Connection (Compliance
With Sec. 23.973(f) Requirements)
In place for compliance with Sec. 23.973(e) and (f), the applicant
must comply with the following:
For airplanes that operate on turbine or diesel type fuels, the
inside diameter of the fuel filler opening must be no smaller than 2.95
inches.
6. Powerplant--Fuel System--Fuel Tank Outlet (Compliance With Sec.
23.977 Requirements)
In place of compliance with Sec. 23.977(a)(1) and (a)(2), the
applicant will comply with the following:
There must be a fuel strainer for the fuel tank outlet or for the
booster pump. This strainer must, for diesel engine powered airplanes,
prevent the passage of any object that could restrict fuel flow or
damage any fuel system component.
7. Powerplant--Powerplant Controls and Accessories--Engine Ignition
Systems (Compliance With Sec. 23.1165 Requirements)
Considering that the FADEC provides the same function as an
ignition system for this diesel engine, in place of compliance to Sec.
23.1165, the applicant will comply with the following:
The electrical system must comply with the following requirements:
(a) In case of failure of one power supply of the electrical
system, there will be no significant engine power changes. The
electrical power supply to the FADEC must remain stable in such a
failure.
(b) The transition from the actual engine electrical network (FADEC
network) to the remaining electrical system should be made at a single
point only. If several transitions (for example, redundancy reasons)
are needed, then the number of the transitions must be kept as small as
possible.
(c) There must be the ability to separate the FADEC power supply
(alternator) from the battery and from the remaining electrical system.
(d) In case of loss of alternator power the installation must
guarantee that the battery will provide the power for an appropriate
time after appropriate warning to the pilot. This period must be at
least 120 minutes.
(e) FADEC, alternator and battery must be interconnected in an
appropriate way, so that in case of loss of battery power, the supply
of the FADEC is guaranteed by the alternator.
8. Equipment--General--Powerplant Instruments (Compliance With Sec.
23.1305 Requirements)
In place of compliance with Sec. 23.1305, the applicant will
comply with the following: The following are required powerplant
instruments:
(a) A fuel quantity indicator for each fuel tank, installed in
accordance with Sec. 23.1337(b).
(b) An oil pressure indicator.
(c) An oil temperature indicator.
(d) A tachometer indicating propeller speed.
(d) A coolant temperature indicator.
(f) An indicating means for the fuel strainer or filter required by
Sec. 23.997 to indicate the occurrence of contamination of the
strainer or filter before it reaches the capacity established in
accordance with Sec. 23.997(d).
Alternately, no indicator is required if the engine can operate
normally for a specified period with the fuel strainer exposed to the
maximum fuel contamination as specified in MIL-
[[Page 67864]]
5007D and provisions for replacing the fuel filter at this specified
period (or a shorter period) are included in the maintenance scheduled
for the engine installation.
(g) Power setting, in percentage.
(h) Fuel temperature.
(i) Fuel flow (engine fuel consumption).
9. Operating Limitations and Information--Powerplant Limitations--Fuel
Grade or Designation (Compliance With Sec. 23.1521(d) Requirements)
Instead of compliance with Sec. 23.1521(d), the applicant must
comply with the following:
The minimum fuel designation (for diesel engines) must be
established so that it is not less than that required for the operation
of the engines within the limitations in paragraphs (b) and (c) of
Sec. 23.1521.
10. Markings and Placards--Miscellaneous Markings and Placards--Fuel,
Oil, and Coolant Filler Openings (Compliance With Sec. 23.1557(c)(1)
Requirements)
Instead of compliance with Sec. 23.1557(c)(1), the applicant must
comply with the following:
Fuel filler openings must be marked at or near the filler cover
with--
For diesel engine-powered airplanes--
(a) The words ``Jet Fuel''; and
(b) The permissible fuel designations, or references to the
Airplane Flight Manual (AFM) for permissible fuel designations.
(c) A warning placard or note that states the following or similar:
``Warning--this airplane equipped with an aircraft diesel engine,
service with approved fuels only.''
The colors of this warning placard should be black and white.
11. Powerplant--Fuel System--Fuel-Freezing
If the fuel in the tanks cannot be shown to flow suitably under all
possible temperature conditions, then fuel temperature limitations are
required. These will be considered as part of the essential operating
parameters for the aircraft and must be limitations.
(1) The takeoff temperature limitation must be determined by
testing or analysis to define the minimum cold-soaked temperature of
the fuel that the airplane can operate on.
(2) The minimum operating temperature limitation must be determined
by testing to define the minimum operating temperature acceptable after
takeoff (with minimum takeoff temperature established in (1) above).
12. Powerplant Installation--Vibration Levels
Vibration levels throughout the engine operating range must be
evaluated and:
(1) Vibration levels imposed on the airframe must be less than or
equivalent to those of the gasoline engine; or
(2) Any vibration level that is higher than that imposed on the
airframe by the replaced gasoline engine must be considered in the
modification and the effects on the technical areas covered by the
following paragraphs must be investigated: 14 CFR part 23, Sec. Sec.
23.251; 23.613; 23.627; 23.629 (or CAR 3.159, as applicable to various
models); 23.572; 23.573; 23.574 and 23.901.
Vibration levels imposed on the airframe can be mitigated to an
acceptable level by utilization of isolators, dampers clutches and
similar provisions, so that unacceptable vibration levels are not
imposed on the previously certificated structure.
13. Powerful Installation--One Cylinder Inoperative
It must be shown by test or analysis, or by a combination of
methods, that the airframe can withstand the shaking or vibratory
forces imposed by the engine if a cylinder becomes inoperative. Diesel
engines of conventional design typically have extremely high levels of
vibration when a cylinder become inoperative. Data must be provided to
the airframe installer/modifier so either appropriate design
considerations or operating procedures, or both, can be developed to
prevent airframe and propeller damage.
14. Powerplant Installation--High Energy Engine Fragments
It may be possible for diesel engine cylinders (or portions
thereof) to fail and physically separate from the engine at high
velocity (due to the high internal pressures). This failure mode will
be considered possible in engine designs with removable cylinders or
other non-integral block designs. The following is required.
(1) It must be shown that the engine construction type (massive or
integral block with nonremovable cylinders) is inherently resistant to
liberating high energy fragments in the event of a catastrophic engine
failure; or,
(2) It must be shown by the design of the engine, that engine
cylinders, other engine components or portions thereof (fragments)
cannot be shed or blown off of the engine in the event of a
catastrophic engine failure; or
(3) It must be shown that all possible liberated engine parts or
components do not have adequate energy to penetrate engine cowlings; or
(4) Assuming infinite fragment energy, and analyzing the trajectory
of the probable fragments and components, any hazard due to liberated
engine parts or components will be minimized and the possibility of
crew injury is eliminated. Minimization must be considered during
initial design and not presented as an analysis after design
completion.
Issued in Kansas City, Missouri, on November 1, 2004.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-25697 Filed 11-19-04; 8:45 am]
BILLING CODE 4910-13-M