7. WHAT ARE THE DEFINITIONS FOR THE COMMON TERMS USED IN THIS ADVISORY CIRCULAR?
This advisory circular uses the definitions listed below. Some of these terms are used throughout, and will only be defined here. Sometimes, the term definitions may be repeated in the relevant document section as an aid to the reader. More definitions and abbreviations are included in 14 CFR part 1, §§ 1.1 and 1.2, respectively.
Aircraft Flight Manual (AFM)
The documentation detailing the operating limitations and instructions for an aircraft.
Airship Design Criteria (ADC)
The design criteria for airships in document number FAA-P-8110-2.
American Society of Testing and Materials (ASTM) International
The ASTM is an international body of producers, consumers, and regulators that develops, maintains, and administers material standards.
Auxiliary Power Unit (APU)
A device, separate from the aircraft propulsion system, that produces power (i.e., electrical, pneumatic, hydraulic) for aircraft systems.
Cabin Pressurization Systems
The collection of components used to pressurize air for airframe services. These systems can have air supplied by any number of means (including turbochargers, engine bleed air, and ram air).
Certificate Management Aircraft Certification Office (CMACO)
The CMACO is the office responsible for aircraft certification. The term is usually shortened to ACO. These offices are located throughout the United States and are each responsible for projects in different States. A listing of these offices can be found by following the certification and design approvals links from the FAA homepage (www.faa.gov).
Civil Air Regulations (CAR)
The body of rules governing aviation before being recodified by final rule on September 28, 1964.
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CAR 3
Part 3 of the Civil Air Regulations as amended through March 25, 1964.
Electronic Engine Control (EEC)
An EEC engine functions electronically in either a supervisory (electronic adjustments to manual inputs) or full authority capacity (see FADEC definition below).
Full Authority Digital Engine Control (FADEC)
A FADEC contains all the engine control functions and exercises full control over engine operations within the pilot selected operating parameters.
High Intensity Radiation Fields (HIRF)
HIRF is electromagnetic fields that emanate from electrical components and occur in nature that can induce current flows in aircraft systems.
Instructions for Continued Airworthiness (ICA)
The documentation detailing “how to” maintain the aircraft, engine, or propeller.
Intercooler
A device installed in the engine air induction system that lowers the intake air charge temperature. The intercooler can be approved either as part of the engine or the engine installation.
Maximum Continuous Power (MCP)
MCP is the maximum power setting the engine is certified to sustain.
Normal Ground Attitude
“Normal ground attitude” is defined as “the aircraft ground attitude that would normally be expected in service.” Therefore, consideration of nose wheel strut, main gear strut, variation of all landing gear tires, and the apron gradient is necessary. Use a minimum ground slope of 1 percent. An appropriate slope for seaplanes/amphibian airplanes would have to be determined from the worst-case static in-water attitude of the aircraft at the most adverse center of gravity location(s).
Reid Vapor Pressure (RVP)
The RVP is a measure of the tendency of a liquid to form vapor.
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RPM
Revolutions per minute
Supercharger
A mechanically driven compressor used to provide and maintain a manifold pressure greater than sea level pressure to a critical altitude.
Type Certificate Data Sheet (TCDS)
The TCDS is attached to the Type Certificate and contains information about the certification basis, design and operating parameters, and limitations for the product.
Turbocharger
Any engine exhaust gas-driven compressor that is a component of a Turbonormalized Engine, Turbosupercharged Engine, or Cabin Pressurization System.
Turbonormalized Engine
Turbocharger used to maintain sea level manifold pressure to a critical altitude.
Turbopropeller
A propeller driven by a turbine engine.
Turbosupercharger
A turbocharger used to provide and maintain a manifold pressure greater than sea level pressure to a critical altitude. This term has been used interchangeably with the term turbocharger.
Turbosupercharged Engine
Turbocharger used to provide and maintain a manifold pressure greater than sea level pressure to a critical altitude.
Unusable fuel
The largest total quantity of fuel remaining in the fuel system when the first evidence of engine malfunction occurs because of fuel interruption. Engine malfunction normally occurs under the most adverse fuel feed conditions. Each intended operation and flight maneuver should be checked for each fuel tank.
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VD
Aircraft design diving speed.
VFE
The maximum airplane flap extended speed.
VNE
Aircraft never-exceed speed
VSO
The airplane stalling speed or the minimum steady flight speed in the landing configuration.
VY
Aircraft best rate-of-climb speed
James E. Jackson Acting Manager, Small Airplane Directorate Aircraft Certification Service xii
CONTENTS
Subpart E⎯Powerplant
GENERAL
Section P AGE
23.901 Installation1
23.903 Engines10
23.904 Automatic power reserve system17
23.905 Propellers18
23.907 Propeller vibration23
23.909 Turbocharger systems25
23.925 Propeller clearance35
23.929 Engine installation ice protection37
23.933 Reversing systems39
23.934 Turbojet and turbofan engine thrust reverser systems tests41
23.937 Turbopropeller-drag limiting systems42
23.939 Powerplant operating characteristics43
23.943 Negative acceleration45
FUEL SYSTEM
23.951 General46
23.953 Fuel system independence49
23.954 Fuel system lightning protection50
23.955 Fuel flow51
23.957 Flow between interconnected tanks63
23.959 Unusable fuel supply64
23.961 Fuel system hot weather operation71
23.963 Fuel tanks: General77
23.965 Fuel tank tests78
23.967 Fuel tank installation80
23.969 Fuel tank expansion space82
23.971 Fuel tank sump83
23.973 Fuel tank filler connection85
23.975 Fuel tank vents and carburetor vapor vents87
23.977 Fuel tank outlet89
23.979 Pressure fueling systems90
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FUEL SYSTEM COMPONENTS
23.991 Fuel pumps91
23.993 Fuel system lines and fittings93
23.994 Fuel system components95
23.995 Fuel valves and controls97
23.997 Fuel strainer or filter99
23.999 Fuel system drains101
23.1001 Fuel jettisoning system102
OIL SYSTEM
23.1011 General104
23.1013 Oil tanks108
23.1015 Oil tank tests110
23.1017 Oil lines and fittings111
23.1019 Oil strainer or filter112
23.1021 Oil system drains113
23.1023 Oil radiators114
23.1027 Propeller feathering system115
COOLING
23.1041 General116
23.1043 Cooling tests117
23.1045 Cooling test procedures for turbine engine powered airplanes119
23.1047 Cooling test procedures for reciprocating engine powered airplanes120
LIQUID COOLING
23.1061 Installation121
23.1063 Coolant tank tests122
INDUCTION SYSTEM
23.1091 Air induction system123
23.1093 Induction system icing protection124
23.1095 Carburetor deicing fluid flow rate135
23.1097 Carburetor deicing fluid system capacity136
23.1099 Carburetor deicing fluid system detail design137
23.1101 Induction air preheater design138
23.1103 Induction system ducts139
23.1105 Induction system screens140
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23.1107 Induction system filters141
23.1109 Turbocharger bleed air system142
23.1111 Turbine engine bleed air system143
EXHAUST SYSTEM
23.1121 General144
23.1123 Exhaust system147
23.1125 Exhaust heat exchangers149
POWERPLANT CONTROLS AND ACCESSORIES
23.1141 Powerplant controls: General150
23.1142 Auxiliary power unit controls152
23.1143 Engine controls153
23.1145 Ignition switches156
23.1147 Mixture controls157
23.1149 Propeller speed and pitch controls158
23.1153 Propeller feathering controls159
23.1155 Turbine engine reverse thrust and propeller pitch settings below the
flight regime160
23.1157 Carburetor air temperature controls162
23.1163 Powerplant accessories163
23.1165 Engine ignition systems165
POWERPLANT FIRE PROTECTION
23.1181 Designated fire zones; regions included167
23.1182 Nacelle areas behind firewalls169
23.1183 Lines, fittings, and components170
23.1189 Shutoff means172
23.1191 Firewalls174
23.1192 Engine accessory compartment diaphragm176
23.1193 Cowling and nacelle177
23.1195 Fire extinguishing systems179
23.1197 Fire extinguishing agents182
23.1199 Extinguishing agent containers183
23.1201 Fire extinguishing systems materials184
23.1203 Fire detector system185
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POWERPLANT GUIDE FOR CERTIFICATION OF PART 23 AIRPLANES
Subpart E⎯Powerplant
GENERAL
23.901 Installation (Amendment 23-53)
CAR 3 Cross-reference: 3.411
ADC Cross-reference: 5.1
What guidance is there for the certification of powerplant electronic systems installations?
Electronic systems are increasingly used to control different airplane systems including powerplant systems. During certification of these installations, § 23.1309 must be used to determine the potential failure modes and the resulting severity of a failure event. A safety analysis is generated during the engine certification that covers engine and engineairplane interfaces. This engine level safety analysis should be used as input to the airplane level safety analysis. Software level requirements for the installed engine should be determined early in the process to ensure the software level certificated for the engine, according to part 33, is compatible with the installation. The engine manufacturer and the Airplane Certification Office should be coordinated with early in the project.
According to § 11.19, special conditions, may be required for powerplant systems installations to comply with the requirements of § 23.1309. These special conditions should not require retesting of the engine or its certificated components except as part of the airplane.
What may be required by special conditions?
Examples of special condition requirements may include, but are not limited to, the following:
1. Lightning test;
2. High Intensity Radiated Fields (HIRF) testing;
3. Software level validation testing; and
4. Environm ental testing.
What are some examples of powerplant electronic systems?
Examples of powerplant electronic systems may include, but are not limited to, the following:
1. Electronic Engine Controls (EEC);
2. Full Authority Digital Engine Controls (FADEC);
3. Electronic turbocharger wastegate controls; and
4. Electronic propeller speed, pitch, and feathering controls.
Related Material
AC 23.1309-1C, Equipment, Systems, and Installations in Part 23 Airplanes
AC 23.1311-1A, Installation of Electronic Displays in Part 23 Airplanes
AC 33.28-1, Compliance Criteria for 14 CFR § 33.28 Aircraft Engines, Electrical and Electronic Engine Control Systems
AC 33.28-2, Guidance Material for 14 CFR § 33.28, Reciprocating Engines, Electrical and Electronic Engine Control Systems
Policy Memorandum ANE-2001-35.31-R0, Policy for Bird Strike, Lightning, and Centrifugal Load Testing for Composite Propeller Blades and Spinners
Paragraph 23.901(a)
ADC Cross-reference: 5.1(a)
What components should be included as part of the powerplant installation?
Examples of powerplant installation components may include, but are not limited to, the following:
1. Engines;
2. Propellers;
3. Gearboxes and engine driven accessories;
4. Nacelles and inlets;
5. Engine oil systems;
6. Fuel tanks, lines, manifolds, and controls;
7. Ignition system components;
8. Propulsion control and monitoring devices;
9. Exhaust nozzles, mufflers, plenums, etc.;
10. Fluid collectors and drain lines;
11. Pneumatic bleed valves and ducting;
12. Engine fire protection systems;
13. Engine and propeller icing protection systems; and
14. Thrust attenuating or reversing installations
Components that are part of an engine or propeller type design certificated under parts 33 or 35, respectively, are considered part of the powerplant installation. Any findings of compliance with part 23 requirements should take maximum advantage of the relevant findings made in support of part 33 or 35.
What regulations should be considered for powerplant installations using technologies other than the typical spark ignition reciprocating and turbine engines?
In the future, designs using engines other than the typical spark ignition reciprocating and turbine engine cycles, such as fuel cell/electric motor, diesel cycle, or even rocket or jet assisted take-off, may be proposed. These designs will require careful selection of the applicable powerplant rules and may require special conditions depending on how similar they are to the typical engines.
Related Material
PS-ACE100-2002-004, Diesel Engine Installation
Paragraph 23.901(b)
ADC Cross-reference: 5.1(b)
What are examples of potential inspection and maintenance items?
Examples of potential powerplant inspection and maintenance items may include, but are not limited to, the following:
1. Oil reservoir fill and quantity sight glasses;
2. Engine control linkages;
3. Oil, fuel, air filters;
4. Oil system chip detectors;
5. Engine mount inspections;
6. Engine exhaust system components; and
7. Firewalls.
What are the typical methods for showing compliance?
Compliance is typically shown using the following methods either alone or in combination:
1. Review of drawings, schematics, system descriptions, and safety analyses;
2. Mock-up inspections and demonstrations;
3. Laboratory and aircraft testing;
4. Comparison with the service experience on similar designs; and
5. Comparison with accepted design standards.
Related Material
AC 23-10, Auxiliary Fuel Systems for Reciprocating and Turbine Powered Part 23 Airplanes
Paragraph 23.901(c)
ADC Cross-reference: 5.1(c)
What are some of the considerations for complying with this rule?
To comply with this rule, the powerplant installation should be designed to provide access (cowling that is easily opened and closed) for the pilot to visually check the following:
1. Engine oil level;