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[Federal Register Volume 74, Number 132 (Monday, July 13, 2009)]
[Rules and Regulations]
[Pages 33324-33327]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-16476]

[[Page 33324]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE298; Special Condition No. 23-238-SC]

Special Conditions: Maule Aerospace Technology, Inc.; Maule Model 
M-7-230, M-7-230C, and M-9-230 Airplanes; Diesel Cycle Engine Using 
Turbine (Jet) Fuel

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Maule Model M-7-
230, M-7-230C, and M-9-230 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 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 July 2, 2009.
    We must receive your comments by August 12, 2009.

ADDRESSES: Mail two copies of your comments to: Federal Aviation 
Administration, Regional Counsel, ACE-7, Attention: Rules Docket CE298, 
901 Locust, Room 506, Kansas City, Missouri 64106. You may deliver two 
copies to the Rules Docket at the above address. Mark your comments 
Docket No. CE298. You may inspect comments 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: 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

    We invite interested persons to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data. We ask 
that you send us two copies of written comments.
    We will file in the docket all comments we receive, as well as a 
report summarizing each substantive public contact with FAA personnel 
about these special conditions. You may inspect the docket before and 
after the comment closing date. If you wish to review the docket in 
person, go to the address in the ADDRESSES section of this preamble 
between 7:30 a.m. and 4 p.m. Monday through Friday, except Federal 
holidays.
    We will consider all comments we receive by the closing date for 
comments. We will consider comments filed late if it is possible to do 
so without incurring expense or delay. We may change these special 
conditions based on the comments we receive.
    If you want us to let you know we received your comments on these 
special conditions, send us a pre-addressed, stamped postcard on which 
the docket number appears. We will stamp the date on the postcard and 
mail it back to you.

Background

    On July 16, 2007, Maule Aerospace Technology, Inc., applied through 
the Atlanta Aircraft Certification Office to amend Type Certificate 
3A23 by certifying derivative Maule airplane Models M-7-230, M-7-230C, 
and M-9-230 to include the installation of a Societe de Motorisation 
Aeronautiques (SMA) Model SR305-230 aircraft diesel engine. The SMA 
Model SR305-230 aircraft diesel engine was previously type certificated 
in the United States under 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 on the Maule Airplane, 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 Sec.  21.101, Maule Aerospace Technology, 
Inc., must show that the Maule Model M-7-230, M-7-230C, and M-9-230 
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 23-55 and Civil Air Regulations (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--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.)

[[Page 33325]]

     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--One cylinder inoperative.
     Powerplant Installation--High Energy Engine Fragments.
    Equivalent levels of safety for:
     Ignition switches Sec.  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.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., part 23) do not contain adequate or appropriate 
safety standards for the Maule Model M-7-230, M-7-230C, and M-9-230 
airplanes with the installation of an SMA Model SR305-230 ADE 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 Maule Model M-7-230, M-7-230C, and M-9-230 airplanes 
with the installation of an SMA Model SR305-230 ADE must comply with 
the noise certification requirements of 14 CFR part 36.
    The FAA issues special conditions, as appropriate, as defined in 
Sec.  11.19, under Sec.  11.38, and they become part of the type 
certification basis under 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 or amended 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 Maule Model M-7-230, M-7-230C, and M-9-230 airplanes with the 
installation of an SMA Model SR305-230 ADE will incorporate the 
following novel or unusual design features: The Maule Model M-7-230, M-
7-230C, and M-9-230 airplanes with the installation of an SMA Model 
SR305-230 ADE will incorporate an aircraft diesel engine utilizing 
turbine (jet) fuel.

Applicability

    As discussed above, these special conditions are applicable to the 
Maule Model M-7-230, M-7-230C, and M-9-230 airplanes with the 
installation of an SMA Model SR305-230 ADE. Should Maule apply at a 
later date for a change to the type certificate to modify any other 
model included on Type Certificate No. 3A23 to incorporate the same 
novel or unusual design feature, the special conditions would apply to 
that model as well.

Conclusion

    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 Maule 
Model M-7-230, M-7-230C, and M-9-230 airplanes is imminent, the FAA 
finds that good cause exists to make these special conditions effective 
upon issuance.
    This action affects only certain novel or unusual design features 
on the Maule Model M-7-230, M-7-230C, and M-9-230 airplanes with the 
installation of an SMA Model SR305-230 ADE. 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

0
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 type certification basis for the Maule Model M-7-230, M-7-230C, and 
M-9-230 airplanes with the installation of an SMA Model SR305-230 ADE.
    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 any structure.
    (b) The limit engine torque obtained in CAR 3.195(a)(1) and (a)(2) 
or 14 CFR Sec.  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 Sec.  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 Sec.  23.629 must include--
    (a) Whirlmode 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--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 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.
    5. Powerplant--Fuel System--Fuel system hot weather operation 
(Compliance with Sec.  23.961 requirements):

[[Page 33326]]

    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.
    6. 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.
    7. 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.
    8. 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, or
    (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.
    9. 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.
    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.
    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. The low temperature limit 
may be 5 [deg]F above the gelling temperature of Jet A with fuel 
additives, if the additives are included in the limitations section of 
the Airplane Flight Manual. A display in the cockpit of either fuel 
temperature or outside temperature is required.
    12. 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.
    13. 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

[[Page 33327]]

    (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 July 2, 2009.
Scott A. Horn,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E9-16476 Filed 7-10-09; 8:45 am]
BILLING CODE 4910-13-P
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