US. Deportment of Transportation Federal Aviation Administration Advisory Circular Subject: FLIGHT TEST GUIDE Date: 11/16/2011 AC No: 23-8C FOR CERTIFICATION OF Initiated By: ACE-100 Change:
PART 23 AIRPLANES
1. Purpose.
a. This advisory circular (AC) sets forth an acceptable means, but not the only means, of showing compliance with Title 14 of the Code of Federal Regulations (14 CFR) part 23 concerning flight tests and pilot judgements. Material in this AC is neither mandatory nor regulatory in nature and does not constitute a regulation.
b. This AC is one method being utilized to achieve national standardization in normal, utility, acrobatic, and commuter category airplanes. This AC applies to Subpart B and various sections under Subparts A, D, E, F and G from § 23.1 through § 23.1589. This AC consolidates existing policy documents, and certain ACs that cover specific paragraphs of the regulations, into a single document.
c. This material is intended as a ready reference for part 23 airplane manufacturers, modifiers, Federal Aviation Administration (FAA) design evaluation engineers, flight test engineers, and engineering flight test pilots, including Organization Delegation Option (DOA).
2. Applicability.
a. The methods and procedures contained in this AC are available for use during all normal, utility, acrobatic, and commuter category airplane flight test certification activities.
This material does not have any legal status and must be treated accordingly. The procedures set forth are one acceptable means of compliance with applicable sections of part 23.
b. Like all AC material, these guidelines are not mandatory and do not constitute a regulation. They came from previous FAA experience in finding compliance with the airworthiness requirements. They represent the methods and procedures found acceptable by that experience. Since these methods and procedures are only one acceptable means of compliance, individuals should be guided by the intent of the methods provided in this AC.
Any alternate means proposed by the applicant will be given due consideration. Applicants should contact their aircraft certification office (ACO) to determine the acceptability of proposed methods.
c. This AC covers the latest part 23 amendments through Amendment 23-62. Each paragraph has the applicable part 23 amendment shown in the title. Prior amendments may require separate procedures and guidance. Applicants should contact their ACO for information concerning policies applicable to prior amendments of part 23 and Civil Air Regulations (CAR 3).
d. Sections entitled "Reserved" will be filled in when the material is developed.
e. This AC is applicable only to the original applicant seeking issuance of a type certificate (TC), an amended TC, or a supplemental type certificate (STC) for the initial approval of the new type design or a change in the approved type design. This material is not to be construed as having any legal status and should be treated accordingly. This version of the AC covers policy available through November 16, 2011. Policy that became available after that date will be covered in future amendments to the AC.
3. Cancellation. The following AC is cancelled: AC 23-8B, Flight Test Guide for Certification of Part 23 Airplanes.
4. General. This AC covers flight test items of interest during type certification. Other engineering disciplines, such as airframe, systems and equipment, and propulsion are addressed as they pertain to flight test criteria.
5. Background.
a. AC 23-8, Flight Test Guide for Certification of Normal, Utility, and Acrobatic Category Airplanes, was published to replace FAA Order 8110.7, Engineering Flight Test Guide for Small Airplanes, dated June 20, 1972, and to consolidate existing flight test policy.
AC 23-8 did not cover commuter category airplanes. AC 23-8A updated the original AC 23 8 by adding information and guidance for commuter airplanes. AC 23-8B updated the Flight Test Guide to incorporate information and guidance through 14 CFR part 23, Amendment
23-51. The AC also incorporated material harmonized with the European Joint Aviation Authorities (JAA).
b. The latest revision to the Flight Test Guide, AC 23-8C, contains guidance material for turbojets certificated under part 23. For almost two decades, part 23 jets used extensive special conditions to address the special issues associated with high performance, high altitude turbojet airplanes. However, in the past five years, the number of new jet certification programs in part 23 has increased more than 100 percent over the program numbers of the past three decades. The need to incorporate these special conditions into part 23 stems not only from the existing number of new jet programs, but expected future programs. This AC is updated to accompany the addition of jet requirements to part 23.
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6. Paragraphs Keyed to Part 23. Each paragraph has the applicable part 23 amendment shown in the title. As part 23 changes occur, the appr opriate revisions will be made to the affected paragraphs of this AC.
7. Related Publications. Certification personnel should be familiar with FAA Order 8110.4 "Type Certification," and FAA Order 8100.5A, "Aircraft Certification Service Mission, Responsibilities, Relationships, and Programs." In this AC, reference is made to other FAA ACs which provide guidance on various aspects of type certification and supplemental type certification. The documents listed below are provided as a quick reference source of documents that are acceptable for use in 14 CFR part 23 certification programs/projects.
a. Copies of current FAA ACs are available on the Internet at http://www.faa.gov/regulations_policies/advisory_circulars/
(1) 20-67 Airborne VHF Communications Equipment Installations
(2) 20-124 Water Ingestion Testing for Turbine Powered Airplanes
(3) 20-118 Emergency Evacuation Demonstration
(4) 20-138B Airworthiness Approval of Positioning and Navigation Systems
(5) 23.629-1 Means of Compliance with Section 23.629, Flutter
(6) 23-1309-1 System Safety Analysis a nd Assessment for Part 23 Airplanes
(7) 23-1419-2 Certification of Part 23 Airplanes for Flight in Icing Conditions
(8) 90-79 Recommended Practices and Procedures for the Use of Electronic Long-Range Navigation Equipment
(9) 91-49 General Aviation Procedures for Flight in North Atlantic Minimum Navigation Performance Specifications Airspace
(10) 121-13 Self-Contained Navigation Systems (Long Range)
(11) 20-88 Guidelines on Marking Aircraft Powerplant Instruments (Displays) iii
(12) 23-16 Powerplant Guide for Certification of Part 23 Airplanes and Airships
(13) 23-1 7 Systems and Equipment Guide for Certification of Part 23 Airplanes and Airships Earl Lawrence Manager, Small Airplane Directorate Aircraft Certification Service iv
Table of Contents
Chapter 1. Subpart A--General1
1. § 23.1 Applicability1
2. § 23.3 Airplane Categories1
Chapter 2 Subpart B – Flight2
Section 1. General2
1. § 23.21 Proof of Compliance2
2. § 23.23 Load Distribution Limits6
3. § 23.25 Weight Limits8
4. § 23.29 Empty Weight and Corre sponding Center of Gravity9
5. § 23.31 Removable Ballast9
6. § 23.33 Propeller Speed and Pitch Limits10
Section 2. Performance11
1. § 23.45 General11
2. § 23.49 Stalling Speed15
3. § 23.51 Takeoff Speeds23
4. § 23.53 Takeoff Performance28
5. § 23.55 Accelerate-Stop Distance32
6. § 23.57 Takeoff Path36
7. § 23.59 Takeoff Distance and Takeoff Run42
8. § 23.61 Takeoff Flight Path45
9. § 23.65 Climb: All Engines Operating47
10. § 23.66 Takeoff Climb, One Engine Inoperative51
11. § 23.67 Climb: One Engine Inoperative52
12. § 23.71 Glide (Single-Engine Airplanes)56
13. § 23.75 Landing57
14. § 23.77 Balked Landing Climb63
Section 3. Flight Characteristics of 14 CFR § 23.14165
1. § 23.141 General65
Section 4. Controllabilit y and Maneuverability65
1. § 23.143 General65
2. § 23.145 Longitudinal Control67
3. § 23.147 Directional and Lateral Control68
4. § 23.149 Minimum Control Speed70
5. § 23.151 Acrobatic Maneuvers74
6. § 23.153 Control During Landings75
7. § 23.155 Elevator Control Force in Maneuvers75
8. § 23.157 Rate of Roll78
Section 5. Trim78
1. § 23.161 Trim78
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Section 6. Stability78
1. § 23.171 General78
2. § 23.173 Static Longitudinal Stability82
3. § 23.175 Demonstration of Static Longitudinal Stability83
4. § 23.177 Static Direction and Lateral Stability86
5. § 23.179 Stability87
6. § 23.181 Dynamic Stability87
Section 7. Stalls92
1. § 23.201 Wings Level Stall92
2. § 23.203 Turning Flight and Accelerated Turning Stalls95
3. § 23.20596
4. § 23.207 Stall Warning96
Section 8. Spinning96
1. § 23.221 Spinning96
Section 9. Ground and Water Ha ndling Characteristics104
1. § 23.231 Longitudinal Stability and Control104
2. § 23.233 Directional Stability and Control104
3. § 23.235 Operation on Unpaved Surfaces106
4. § 23.237 Operation on Water106
5. § 23.239 Spray Characteristics106
Section 10. Miscellaneous Flight Requirements106
1. § 23.251 Vibration and Buffering106
2. § 23.253 High Speed Characteristics107
Chapter 3. Subpart D--Design and Construction111
Section 1. General111
1. § 23.629 Flutter111
Section 2. Control Systems111
1. § 23.671 General111
2. § 23.672 Stability Augmentation and Automatic and Power Operated Systems111
3. § 23.677 Trim Systems111
4. § 23.679 Control System Locks113
5. § 23.689 Cable Systems113
6. § 23.691 Artificial Stall Barrier System114
7. § 23.697 Wing Flap Controls114
8. § 23.699 Wing Flap Position Indicator114
9. § 23.701 Flap Interconnection114
Section 3. Landing Gear114
1. § 23.729 Landing Gear Extension and Retraction System114
2. § 23.735 Brakes114
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Section 4. Personnel and Cargo Accommodations114
1. § 23.771 Pilot Compartment114
2. § 23.773 Pilot Compartment View114
3. § 23.775 Windshields and Windows115
4. § 23.777 Cockpit Controls115
5. § 23.785 Seats, Berths, Litters, Safe ty Belts and Shoulder Harnesses115
6. § 23.803 Emergency Evacuation116
7. § 23.807 Emergency Exits116
8. § 23.831 Ventilation116
Section 5. Pressurization117
1. § 23.841 Pressurization Cabins117
2. § 23.843 Pressurization Tests117
Chapter 4. Subpart E--Powerplant118
Section 1. General118
1. § 23.901 Installation118
2. § 23.903 Engines118
3. § 23.905 Propellers121
4. § 23.909 Turbo Superchargers121
5. § 23.925 Propeller Clearance121
6. § 23.929 Engine Installation Ice Protection121
7. § 23.933 Reversing Systems121
8. § 23.939 Powerplant Operating Characteristics122
9. § 23.943 Negative Acceleration123
Section 2. Fuel System123
1. § 23.959 Unusable Fuel Supply123
2. § 23.961 Fuel System Hot Weather Operation123
Section 3. Fuel System Components123
1. § 23.1001 Fuel Jettisoning System123
Section 4. Oil System124
1. § 23.1027 Propeller Feathering System124
Section 5. Cooling125
1. § 23.1041 General125
2. § 23.1043 Cooling Tests125
3. § 23.1045 Cooling Test Procedures for Turbine Engine-Powered Airplanes125
4. § 23.1047 Cooling Test Procedures for Reci procating Engine-Powered Airplanes129
Section 6. Induction System132
1. § 23.1091 Air Induction132
2. § 23.1093 Induction System Icing Protection132
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Section 7. Powerplant Controls and Accessories136
1. § 23.1141 Powerplant Controls: General137
2. § 23.1145 Ignition Switches137
3. § 23.1153 Propeller Feathering Controls137
Section 8. Powerplant Fire Protection137
1. § 23.1189 Shutoff Means137
Chapter 5. Subpart F--Equipment138
Section 1. General138
1. § 23.1301 Function and Installation138
2. § 23.1303 Flight and Navi gation Instruments147
3. § 23.1305 Powerplant Instruments147
4. § 23.1307 Miscellaneous Equipment148
5. § 23.1309 Equipment, Systems, and Installations148
Section 2. Instruments: Installation148
1. § 23.1311 Electronic Display Instrument Systems148
2. § 23.1321 Arrangement and Visibility148
3. § 23.1322 Warning, Caution, and Advisory Lights148
4. § 23.1323 Airspeed Indicating System148
5. § 23.1325 Static Pressure System149
6. § 23.1326 Pitot Heat Indication Systems152
7. § 23.1327 Magnetic Direction Indicator152
8. § 23.1329 Automatic Pilot System152
9. § 23.1331 Instruments Using a Power Supply152
10. § 23.1335 Flight Director Systems152
11. § 23.1337 Powerplant Instruments152
Section 3. Electrical Systems and Equipment152
1. § 23.1351 General152
2. § 23.1353 Storage Battery Design and Installation153
Reserved153
3. § 23.1357 Circuit Protective Devices153
4. § 23.1361 Master Switch Switch Arrangement153
5. § 23.1367 Switches153
Section 4. Lights153
1. § 23.1381 Instrument Lights153
2. § 23.1383 Landing Lights153
Section 5. Safety Equipment153
1. § 23.1411 General153
2. § 23.1415 Ditching Equipment153
3. § 23.1416 Pneumatic Deicer Boot System153
4. § 23.1419 Ice Protection153
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Section 6. Miscellaneous Equipment153
1. § 23.1431 Electronic Equipment153
2. §23.1435 Hydraulic Systems153
3. § 23.1441 Oxygen Equipment and Supply153
4. § 23.1447 Equipment Standards for Oxygen Dispensing Units153
5. § 23.1449 Means for Determining Use of Oxygen153
6. § 23.1457 Cockpit Voice Recorders153
7. § 23.1459 Flight Data Recorders154
Chapter 6. Subpart G--Operating Limitations and Information155
Section 1. General155
1 § 23.1501 General155
2. § 23.1505 Airspeed Limitations155
3. § 23.1507 Maneuvering Speed155
4. § 23.1511 Flap Extended Speed155
5. § 23.1513 Minimum Control Speed155
6. § 23.1519 Weight and Center of Gravity155
7. § 23.1521 Powerplant Limitations155
8. § 23.1523 Minimum Flight Crew156
9. § 23.1523 Minimum Flight Crew156
10. § 23.1524 Maximum Passenger Seating Configuration160
11. § 23.1525 Kinds of Operation160
12. § 23.1527 Maximum Operating Altitude160
Section 2. Markings and Placards161
1. § 23.1541 General161
2. § 23.1543 Instrument Markings: General162
3. § 23.1545 Airspeed Indicator162
4. § 23.1547 Magnetic Direction Indicator162
5. § 23.1549 Powerplant Instruments162
6. § 23.1551 Oil Quantity Indicator162
7. § 23.1553 Fuel Quantity Indicator162
8. § 23.1555 Control Markings162
9. § 23.1557 Miscellaneous Markings and Placards162
10. § 23.1559 Operating Limitations Placard162
11. § 23.1561 Safety Equipment162
12. § 23.1563 Airspeed Placards163
13. § 23.1567 Flight Maneuver Placard163
Section 3. Airplane Flight Manual and Approved Manual Material163
1. § 23.1581 General163
2. § 23.1583 Operating Limitations165
3. § 23.1585 Operating Procedures167
4. § 23.1587 Performance Information168
5. § 23.1589 Loading Information170
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Appendix 1. Power Available
1. General
2. Reciprocating Engines
3. Normally Aspirated Engines with Constant Speed Propellers
4. Turbocharged Engines with Constant Speed Propellers
5. Normally Aspirated Engines with Fixed Pitch Propellers
6. Turbopropeller Engines Appendix 2. Climb Data Reduction
1. Drag Polar Method
2. Density Altitude Method Appendix 3. Static Minimum Control Speed
1. General
2. Calculation Method
3. Cautions and Assumptions
4. Sample Calculations Appendix 4 FAR-23 Manuals, Markings, & Placards Checklist Appendix 5 –Guide for Preparing Airplane Flight Manual and Pilots’s Operating Handbook Supplements
1. Introduction
2. General Appendix 6. Sample Kinds of Operating Equipment List Appendix 7. Useful Information Appendix 8. Conversion Factors Table Appendix 9. Airspeed Calibrations Introduction General Discussion of the Various Flight Test Techniques
1. Trailing Bomb or Cone Method
2. Speed Course Method
3. GPS Method
4. Pace Airplane Method
5. Pitot Static Boom Data
6. Tower Fly By Method
7. Ground Run Airspeed System Calibration Appendix 10. Guide for Determining Clim b Performance After STC Modifications
1. Introduction
2. General
3. Procedure for Extending Climb Performance to Additional Airplanes
4. ‘One Only’ Airplane x
List of Figures
Figure 1 Stall Speed17
Figure A1-1 – Brake Horsepow er Versus Pressure Altitude Figure A1-2 - Turbocharged Brake Horsepower Versus Altitude Figure A2-1 - Coefficient of Drag Versus Coefficient of Lift Figure A3-1 - Thrust Horsepower at Sea Level Figure A7-1 – U.S. Standard Atmosphere (1962) Figure A7-2 – Temperature Conversion Chart Figure A7-3 – Determination of Air Temperature in Relation to International Standard Atmosphere Figure A7-4 – Density/Pressure Altitude Conversion Figure A7-5 – Compressibility Correction CAS Figure A7-6 – Altimeter Error vs. CAS Figure A7-7 – Temperature RAM Rise Figure A7-8 – Stalling Speed as a Function of Angle of Bank Figure A7-9 – Vectoral Acceleration Versus Angle of Bank Figure A7-10 Figure A7-11 – Takeoff and Landing Crosswind Component Chart Figure A9-1 - Error Analysis of Ground Course Method
Figure 2 Propeller Coefficients19
Figure 3 Zero Thrust19
Figure 4 Thrust Effect on Stall C L20
Figure 5 - Accelerate-Stop Time Delays35
Figure 6 Takeoff Distance Critical Engine Failure Recognized at V143
Figure 7 - Takeoff Distance - All Engines Operating43
Figure 8 - Takeoff Run - Critical Engine Failure Recognized at V144
Figure 9 - Takeoff Run - All Engines Operating44
Figure 10 - Clearway Profiles45
Figure 11 - Takeoff Segments and Nomenclature46
Figure 12- Net Takeoff Flight Path47
Figure 13 - Observed Data49
Figure 14 - Rate of Climb vs. Airspeed51
Figure 15 - Rate of Climb and Speeds52
Figure 16 - Landing Time Delays61
Figure 17 - Stick Force Per G77
Figure 18 - Static Longitudinal Stability Data80
Figure 19 - Low Speed Instabilities; Normal, Utility, and Acrobatic Airplanes81
Figure 20 - Low Speed Instabilities; Commuter Airplanes82
Figure 21 – Static Longitudinal Stability Data over Complete Speed Range83
Figure 22 - Static Longitudinal Stability Plot (Cruise Condition)86
Figure 23 - Spin Evaluation Configuration Matrix103
Figure 24 – Sample Calculation128
Figure 25 – Corrected Cylinder Barrel Temperature131
Figure 26 – Correct Cylinder Head Temperature132
Figure 27 - Carburetor Air Heat Rise Calculations135
Figure 28 - Carburetor Air Heat Rise Plots136
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Figure A9-2 - Summary of PEC Test Methods Figure A9-3 - Sketches of Trailing Static Bomb and the Trailing Static Cone (not to scale) Figure A9-4 - Typical Position Error Correction Data for an Aircraft Figure A9-5 Typical Position Error Corrections Data for an Aircraft Figure A9-6 Tower Fly-By Method Figure A9-7 - Trapped Static Source Schematic Figure A9-8 - Ground Airspeed Calibration xii