[Federal Register Volume 70, Number 10 (Friday, January 14, 2005)]
[Rules and Regulations]
[Pages 2561-2564]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-852]



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  Federal Register / Vol. 70, No. 10 / Friday, January 14, 2005 / Rules 
and Regulations  

[[Page 2561]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE214; Special Conditions No. 23-157-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: Final special conditions.

-----------------------------------------------------------------------

SUMMARY: These special conditions are issued for the Cessna Model 172 
airplane. This airplane as modified by Thielert Aircraft Engines GmbH 
will have a novel or unusual design feature(s) associated with the 
installation of an aircraft diesel engine. 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: Effective January 6, 2005.

FOR FURTHER INFORMATION CONTACT: Peter Rouse, Federal Aviation 
Administration, Aircraft Certification Service, Small Airplane 
Directorate, ACE-111, 901 Locust, Room 301, Kansas City, Missouri 
64106; 816-329-4135, fax 816-329-4090, e-mail [email protected].

SUPPLEMENTARY INFORMATION:

Background

    On February 11, 2002, Thielert Aircraft Engines GmbH applied for a 
supplemental type certificate for installation of an aircraft diesel 
engine in the Cessna Model 172 airplane. The Cessna 172 series 
airplanes are currently approved under Type Certificate No. 3A13, and 
they are four-place, high wing, fixed tricycle landing gear, 
conventional planform airplanes. The Cessna 172 airplanes affected have 
gross weights in the range of 2300 to 2558 pounds in the normal 
category. The affected series of airplanes have been equipped with 
gasoline reciprocating engines of 160 to 180 horsepower.

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 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, 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 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,

[[Page 2562]]

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, 
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--Installation--23.1061
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 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 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.

Discussion of Comments

    Notice of proposed special conditions No. 23-04-02-SC for the 
Thielert Aircraft Engines, GmbH, Cessna Model 172 Series airplanes was 
published on November 22, 2004, (69 FR 67860). No comments were 
received, and the special conditions are adopted as proposed.

Applicability

    As discussed above, these special conditions are applicable to the 
Thielert Aircraft Engines GmbH, Cessna Model 172 Series. 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. 3A12 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(a)(1).
    Under standard practice, the effective date of final special 
conditions would be 30 days after the date of publication in the 
Federal Register; however, as the certification date for the Thielert 
Aircraft Engines GmbH, Cessna Model 172 Series is imminent, the FAA 
finds that good cause exists to make these special conditions effective 
upon issuance.

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.

The Special Conditions

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for Thielert Aircraft Engines GmbH, Cessna 
Model 172 Series 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

[[Page 2563]]

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 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 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.

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 toSec.  
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 change. 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.
    (e) 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

[[Page 2564]]

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.
    (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. 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. 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 non-removable 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 January 6, 2005.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-852 Filed 1-13-05; 8:45 am]
BILLING CODE 4910-13-P