[Federal Register: February 17, 2006 (Volume 71, Number 33)]
[Proposed Rules]
[Page 8543-8547]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17fe06-22]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE239; Notice No. 23-06-01-SC]
Special Conditions: Societe de Motorisation Aeronautiques (SMA)
Engines, Inc., Cessna Models 182Q and 182R; 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 notice proposes special conditions for the Cessna Models
182Q and 182R airplanes with a Societe de Motorisation Aeronautiques
(SMA) Model SR305-230 aircraft diesel engine (ADE). This airplane 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 existing
airworthiness standards.
DATES: Comments must be received on or before June 19, 2006.
ADDRESSES: Comments on this proposal may be mailed in duplicate to:
Federal Aviation Administration, Regional Counsel, ACE-7, Attention:
Rules Docket, Docket No. CE239, 901 Locust, Room 506, Kansas City,
Missouri 64106, or delivered in duplicate to the Regional Counsel at
the above address. Comments must be marked: CE239. 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: Peter L. 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
[[Page 8544]]
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
CE239.'' The postcard will be date stamped and returned to the
commenter.
Background
An application for a Supplemental Type Certification of Cessna
Models 182Q and 182R airplanes for the installation of an SMA Model
SR305-230 was made on March 19, 2004, by the Societe de Motorisation
Aeronautiques (SMA) Engines, Inc. through the Atlanta Aircraft
Certification Office (ACO). The airplane is powered by a SMA Model
SR305-230 aircraft diesel engine (ADE), type certificated in the United
States, type certificate number E00067EN.
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, 2004, 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, and the
vibration characteristics and failure modes of diesel engines. These
concerns were identified after review of the historical record of
diesel engine used in aircraft and a review of the 14 CFR part 23
regulations, which identified specific regulatory areas that needed to
be evaluated for applicability to diesel engine installations. These
concerns are not considered universally applicable to all types of
possible diesel engines and diesel engine installations. However, after
review of the SMA installation, and applying the provisions of the
diesel policy, the FAA proposes these fuel system and engine related
special conditions. Other special conditions issued in a separate
notice include 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 14 CFR 21.17, Societe de Motorisation
Aeronautiques (SMA) Engines, Inc. must show that the Cessna Models 182Q
and 182R airplanes with the installation of an SMA Model SR305-230 meet
the applicable provisions of 14 CFR part 23, as amended by Amendments
23-1 through 23-51 and CAR 3 thereto. In addition, the certification
basis includes special conditions and equivalent levels of safety for
the following:
Special Conditions:
Engine torque (Provisions similar to Sec. 23.361,
paragraphs (b)(1) and (c)(3)).
Flutter (Compliance with Sec. 23.629, paragraphs (e)(1)
and (2)).
Powerplant--Installation (Provisions similar to Sec.
23.901(d)(1) for turbine engines).
Powerplant--Fuel System--Fuel system with water saturated
fuel (Compliance with Sec. 23.951 requirements).
Powerplant--Fuel System--Fuel system hot weather operation
(Compliance with Sec. 23.961 requirements).
Powerplant--Fuel system--Fuel tank filler connection
(Compliance with Sec. 23.973(f) requirements).
Powerplant--Fuel system--Fuel tank outlet (Compliance with
Sec. 23.977 requirements).
Equipment--General--Powerplant Instruments (Compliance
with Sec. 23.1305 requirements).
Operating Limitations and Information--Powerplant
limitations--Fuel grade or designation (Compliance with Sec.
23.1521(d) requirements).
Markings and Placards--Miscellaneous markings and
placards--Fuel, oil, and coolant filler openings (Compliance with Sec.
23.1557(c)(1) requirements).
Powerplant--Fuel system--Fuel-Freezing.
Powerplant Installation--Vibration levels.
Powerplant Installation--One cylinder inoperativ.e
Powerplant Installation--High Energy Engine Fragments.
Equivalent levels of safety for:
Cockpit controls--23.777(d).
Motion and effect of cockpit controls--23.779(b).
Ignition switches--23.1145.
The type certification basis includes exemptions, 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 Models 182Q and 182R airplanes with the
installation of an SMA Model SR305-230 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 Models 182Q and 182R airplanes with the
installation of an SMA Model SR305-230 must comply with the 14 CFR
21.115 noise certification requirements of 14 CFR part 36.
Special conditions, as appropriate, as defined in Sec. 11.19, are
issued in accordance with Sec. 11.38, and become part of the type
certification basis in accordance with Sec. 21.17.
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. 21.17.
Novel or Unusual Design Features
The Cessna Models 182Q and 182R airplanes with the installation of
an SMA Model SR305-230 will incorporate the following novel or unusual
design features:
The Cessna Models 182Q and 182R airplanes with the installation of
an SMA Model SR305-230 will incorporate an aircraft diesel engine
utilizing turbine (jet) fuel.
Applicability
As discussed above, these special conditions are applicable to the
Cessna Models 182Q and 182R airplanes with the installation of an SMA
Model SR305-230.
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.
[[Page 8545]]
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
21.17; 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 aircraft diesel engine installation 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, requirements 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-tests
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 compatibility 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)(i) will not apply.
``Turbine engine'' is interpreted to mean ``aircraft diesel engine''
for this requirement.
Limitations and Indications:
Critical engine parameters for this installation that will be
displayed include the following:
(1) 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 182Q or 182R airplane with SMA SR305-230 installed.
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:
(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 obtained in CAR 3.195(a)(1) and (a)(2)
or 14 CFR 23.361(a)(1) and (a)(2) must be obtained by multiplying the
mean torque by a factor of four in lieu of the factor of two required
by CAR 3.195(b) and 14 CFR 23.361(c)(3).
2. Flutter--(Compliance With Sec. 23.629 (e)(1) and (e)(2)
Requirements)
The flutter evaluation of the airplane done in accordance with 14
CFR 23.629 must include--
(a) Whirl mode degree of freedom which takes into account the
stability of the plane of rotation of the propeller and significant
elastic, inertial, and aerodynamic forces, and
(b) Propeller, engine, engine mount and airplane structure
stiffness and damping variations appropriate to the particular
configuration, and
(c) Showing the airplane is free from flutter with one cylinder
inoperative.
3. 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.
4. 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.
[[Page 8546]]
5. Powerplant--Fuel System--Fuel Flow (Compliance With Sec. 23.955(c)
Requirements)
In lieu of 14 CFR 23.955(c), engine fuel system must provide at
least 100 percent of the fuel flow required by the engine, or the fuel
flow required to prevent engine damage, if that flow is greater than
100 percent. The fuel flow rate must be available to the engine under
each intended operating condition and maneuver. The conditions may be
simulated in a suitable mockup. This flow must be shown in the most
adverse fuel feed condition with respect to altitudes, attitudes, and
any other condition that is expected in operation.
6. 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.
7. Powerplant--Fuel System--Fuel Tank Filler Connection (Compliance
With Sec. 23.973(f) Requirements)
In place of 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.
8. 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.
9. Equipment--General--Powerplant Instruments (Compliance With Sec.
23.1305)
In addition to compliance with Sec. 23.1305, the applicant will
comply with the following:
The following are required in addition to the powerplant
instruments required in Sec. 23.1305:
(a) A fuel temperature indictor.
(b) An outside air temperature (OAT) indicator.
(c) 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-5007D and provisions for
replacing the fuel filter at this specified period (or a shorter
period) are included in the maintenance schedule for the engine
installation.
10. Operating Limitations and Information--Powerplant Limitations--Fuel
Grade or Designation (Compliance With Sec. 23.1521 Requirements)
All engine parameters that have limits specified by the engine
manufacturer for takeoff or continuous operation must be investigated
to ensure they remain within those limits throughout the expected
flight and ground envelopes (e.g. maximum and minimum fuel
temperatures, ambient temperatures, as applicable, etc.). This is in
addition to the existing requirements specified by 14 CFR 23.1521(b)
and (c). If any of those limits can be exceeded, there must be
continuous indication to the flight crew of the status of that
parameter with appropriate limitation markings.
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.
11. 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.
12. 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.
A minimum takeoff temperature limitation will be determined by
testing to establish the minimum cold-soaked temperature at which the
airplane can operate. The minimum operating temperature will be
determined by testing to establish the minimum operating temperature
acceptable after takeoff from the minimum takeoff temperature. If low
temperature limits are not established by testing, then a minimum
takeoff and operating fuel temperature limit of 5[deg] F above the
gelling temperature of Jet A will be imposed along with a display in
the cockpit of the fuel temperature. Fuel temperature sensors will be
located in the coldest part of the tank if applicable.
13. 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
[[Page 8547]]
investigated: 14 CFR 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.
14. Powerplant 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 becomes inoperative.
No unsafe condition will exist in the case of an inoperative
cylinder before the engine can be shut down. The resistance of the
airframe structure, propeller, and engine mount to shaking moment and
vibration damage must be investigated. It must be shown by test or
analysis, or by a combination of methods, that shaking and vibration
damage from the engine with an inoperative cylinder will not cause a
catastrophic airframe, propeller, or engine mount failure.
15. 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 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
(2) It must be shown that all possible liberated engine parts or
components do not have adequate energy to penetrate engine cowlings; or
(3) 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 eliminated. Minimization must be considered during initial
design and not presented as an analysis after design completion.
Issued in Kansas City, Missouri on February 9, 2006.
Patrick R. Mullen,
Acting Manager, Small Airplane Directorate. Aircraft Certification
Service.
[FR Doc. E6-2285 Filed 2-16-06; 8:45 am]
BILLING CODE 4910-13-P