Federal Aviation Regulations

Part 23: Airworthiness standards: Normal, utility, acrobatic, and commuter category airplanes

Special Federal Aviation Regulations

• SFAR No. 23

Federal Aviation Regulations

Subpart A - General


• Sec. 23.1 - Applicability.
• Sec. 23.2 - Special retroactive requirements.
• Sec. 23.3 - Airplane categories.

Subpart B - Flight



• Sec. 23.21 - Proof of compliance.
• Sec. 23.23 - Load distribution limits.
• Sec. 23.25 - Weight limits.
• Sec. 23.29 - Empty weight and corresponding center of gravity.
• Sec. 23.31 - Removable ballast.
• Sec. 23.33 - Propeller speed and pitch limits.
• Sec. 23.45 - General.
• Sec. 23.49 - Stalling period.
• Sec. 23.51 - Takeoff speeds.
• Sec. 23.53 - Takeoff performance.
• Sec. 23.55 - Accelerate-stop distance.
• Sec. 23.57 - Takeoff path.
• Sec. 23.59 - Takeoff distance and takeoff run.
• Sec. 23.61 - Takeoff flight path.
• Sec. 23.63 - Climb: General.
• Sec. 23.65 - Climb: All engines operating.
• Sec. 23.66 - Takeoff climb: One-engine inoperative.
• Sec. 23.67 - Climb: One engine inoperative.
• Sec. 23.69 - Enroute climb/descent.
• Sec. 23.71 - Glide: Single-engine airplanes.
• Sec. 23.73 - Reference landing approach speed.
• Sec. 23.75 - Landing distance.
• Sec. 23.77 - Balked landing.
• Sec. 23.141 - General.
• Sec. 23.143 - General.
• Sec. 23.145 - Longitudinal control.
• Sec. 23.147 - Directional and lateral control.
• Sec. 23.149 - Minimum control speed.
• Sec. 23.151 - Acrobatic maneuvers.
• Sec. 23.153 - Control during landings.
• Sec. 23.155 - Elevator control force in maneuvers.
• Sec. 23.157 - Rate of roll.
• Sec. 23.161 - Trim.
• Sec. 23.171 - General.
• Sec. 23.173 - Static longitudinal stability.
• Sec. 23.175 - Demonstration of static longitudinal stability.
• Sec. 23.177 - Static directional and lateral stability.
• Sec. 23.181 - Dynamic stability.
• Sec. 23.201 - Wings level stall.
• Sec. 23.203 - Turning flight and accelerated turning stalls.
• Sec. 23.207 - Stall warning.
• Sec. 23.221 - Spinning.
• Sec. 23.231 - Longitudinal stability and control.
• Sec. 23.233 - Directional stability and control.
• Sec. 23.235 - Operation on unpaved surfaces.
• Sec. 23.237 - Operation on water.
• Sec. 23.239 - Spray characteristics.
• Sec. 23.251 - Vibration and buffeting.
• Sec. 23.253 - High speed characteristics.

Subpart C - Structure



• Sec. 23.301 - Loads.
• Sec. 23.302 - Canard or tandem wing configurations.
• Sec. 23.303 - Factor of safety.
• Sec. 23.305 - Strength and deformation.
• Sec. 23.307 - Proof of structure.
• Sec. 23.321 - General.
• Sec. 23.331 - Symmetrical flight conditions.
• Sec. 23.333 - Flight envelope.
• Sec. 23.335 - Design airspeeds.
• Sec. 23.337 - Limit maneuvering load factors.
• Sec. 23.341 - Gust loads factors.
• Sec. 23.343 - Design fuel loads.
• Sec. 23.345 - High lift devices.
• Sec. 23.347 - Unsymmetrical flight conditions.
• Sec. 23.349 - Rolling conditions.
• Sec. 23.351 - Yawing conditions.
• Sec. 23.361 - Engine torque.
• Sec. 23.363 - Side load on engine mount.
• Sec. 23.365 - Pressurized cabin loads.
• Sec. 23.367 - Unsymmetrical loads due to engine failure.
• Sec. 23.369 - Rear lift truss.
• Sec. 23.371 - Gyroscopic and aerodynamic loads.
• Sec. 23.373 - Speed control devices.
• Sec. 23.391 - Control surface loads.
• Sec. 23.393 - Loads parallel to hinge line.
• Sec. 23.395 - Control system loads.
• Sec. 23.397 - Limit control forces and torques.
• Sec. 23.399 - Dual control system.
• Sec. 23.405 - Secondary control system.
• Sec. 23.407 - Trim tab effects.
• Sec. 23.409 - Tabs.
• Sec. 23.415 - Ground gust conditions.
• Sec. 23.421 - Balancing loads.
• Sec. 23.423 - Maneuvering loads.
• Sec. 23.425 - Gust loads.
• Sec. 23.427 - Unsymmetrical loads.
• Sec. 23.441 - Maneuvering loads.
• Sec. 23.443 - Gust loads.
• Sec. 23.445 - Outboard fins or winglets.
• Sec. 23.455 - Ailerons.
• Sec. 23.459 - Special devices.
• Sec. 23.471 - General.
• Sec. 23.473 - Ground load conditions and assumptions.
• Sec. 23.477 - Landing gear arrangement.
• Sec. 23.479 - Level landing conditions.
• Sec. 23.481 - Tail down landing conditions.
• Sec. 23.483 - One-wheel landing conditions.
• Sec. 23.485 - Side load conditions.
• Sec. 23.493 - Braked roll conditions.
• Sec. 23.497 - Supplementary conditions for tail wheels.
• Sec. 23.499 - Supplementary conditions for nose wheels.
• Sec. 23.505 - Supplementary conditions for skiplanes.
• Sec. 23.507 - Jacking loads.
• Sec. 23.509 - Towing loads.
• Sec. 23.511 - Ground load; unsymmetrical loads on multiple-wheel units.
• Sec. 23.521 - Water load conditions.
• Sec. 23.523 - Design weights and center of gravity positions.
• Sec. 23.525 - Application of loads.
• Sec. 23.527 - Hull and main float load factors.
• Sec. 23.529 - Hull and main float landing conditions.
• Sec. 23.531 - Hull and main float takeoff condition.
• Sec. 23.533 - Hull and main float bottom pressures.
• Sec. 23.535 - Auxiliary float loads.
• Sec. 23.537 - Seawing loads.
• Sec. 23.561 - General.
• Sec. 23.562 - Emergency landing dynamic conditions.
• Sec. 23.571 - Metallic pressurized cabin structures.
• Sec. 23.572 - Metallic wing, empennage, and associated structures.
• Sec. 23.573 - Damage tolerance and fatigue evaluation of structure.
• Sec. 23.574 - Metallic damage tolerance and fatigue evaluation of commuter category airplanes.
• Sec. 23.575 - Inspections and other procedures.

Subpart D - Design and Construction



• Sec. 23.601 - General.
• Sec. 23.603 - Materials and workmanship.
• Sec. 23.605 - Fabrication methods.
• Sec. 23.607 - Fasteners.
• Sec. 23.609 - Protection of structure.
• Sec. 23.611 - Accessibility provisions.
• Sec. 23.613 - Material strength properties and design values.
• Sec. 23.619 - Special factors.
• Sec. 23.621 - Casting factors.
• Sec. 23.623 - Bearing factors.
• Sec. 23.625 - Fitting factors.
• Sec. 23.627 - Fatigue strength.
• Sec. 23.629 - Flutter.
• Sec. 23.641 - Proof of strength.
• Sec. 23.651 - Proof of strength.
• Sec. 23.655 - Installation.
• Sec. 23.657 - Hinges.
• Sec. 23.659 - Mass balance.
• Sec. 23.671 - General.
• Sec. 23.672 - Stability augmentation and automatic and power-operated systems.
• Sec. 23.673 - Primary flight controls.
• Sec. 23.675 - Stops.
• Sec. 23.677 - Trim systems.
• Sec. 23.679 - Control system locks.
• Sec. 23.681 - Limit load static tests.
• Sec. 23.683 - Operation tests.
• Sec. 23.685 - Control system details.
• Sec. 23.687 - Spring devices.
• Sec. 23.689 - Cable systems.
• Sec. 23.691 - Artificial stall barrier system.
• Sec. 23.693 - Joints.
• Sec. 23.697 - Wing flap controls.
• Sec. 23.699 - Wing flap position indicator.
• Sec. 23.701 - Flap interconnection.
• Sec. 23.703 - Takeoff warning system.
• Sec. 23.721 - General.
• Sec. 23.723 - Shock absorption tests.
• Sec. 23.725 - Limit drop tests.
• Sec. 23.726 - Ground load dynamic tests.
• Sec. 23.727 - Reserve energy absorption drop test.
• Sec. 23.729 - Landing gear extension and retraction system.
• Sec. 23.731 - Wheels.
• Sec. 23.733 - Tires.
• Sec. 23.735 - Brakes.
• Sec. 23.737 - Skis.
• Sec. 23.745 - Nose/tail wheel steering.
• Sec. 23.751 - Main float buoyancy.
• Sec. 23.753 - Main float design.
• Sec. 23.755 - Hulls.
• Sec. 23.757 - Auxiliary floats.
• Sec. 23.771 - Pilot compartment.
• Sec. 23.773 - Pilot compartment view.
• Sec. 23.775 - Windshields and windows.
• Sec. 23.777 - Cockpit controls.
• Sec. 23.779 - Motion and effect of cockpit controls.
• Sec. 23.781 - Cockpit control knob shape.
• Sec. 23.783 - Doors.
• Sec. 23.785 - Seats, berths, litters, safety belts, and shoulder harnesses.
• Sec. 23.787 - Baggage and cargo compartments.
• Sec. 23.791 - Passenger information signs.
• Sec. 23.803 - Emergency evacuation.
• Sec. 23.805 - Flightcrew emergency exits.
• Sec. 23.807 - Emergency exits.
• Sec. 23.811 - Emergency exit marking.
• Sec. 23.812 - Emergency lighting.
• Sec. 23.813 - Emergency exit access.
• Sec. 23.815 - Width of aisle.
• Sec. 23.831 - Ventilation.
• Sec. 23.841 - Pressurized cabins.
• Sec. 23.843 - Pressurization tests.
• Sec. 23.851 - Fire extinguishers.
• Sec. 23.853 - Passenger and crew compartment interiors.
• Sec. 23.855 - Cargo and baggage compartment fire protection.
• Sec. 23.859 - Combustion heater fire protection.
• Sec. 23.863 - Flammable fluid fire protection.
• Sec. 23.865 - Fire protection of flight controls, engine mounts, and other flight structure.
• Sec. 23.867 - Electrical bonding and protection against lightning and static electricity.
• Sec. 23.871 - Leveling means.

Subpart E - Powerplant



• Sec. 23.901 - Installation.
• Sec. 23.903 - Engines.
• Sec. 23.904 - Automatic power reserve system.
• Sec. 23.905 - Propellers.
• Sec. 23.907 - Propeller vibration.
• Sec. 23.909 - Turbocharger systems.
• Sec. 23.925 - Propeller clearance.
• Sec. 23.929 - Engine installation ice protection.
• Sec. 23.933 - Reversing systems.
• Sec. 23.934 - Turbojet and turbofan engine thrust reverser systems tests.
• Sec. 23.937 - Turbopropeller-drag limiting systems.
• Sec. 23.939 - Powerplant operating characteristics.
• Sec. 23.943 - Negative acceleration.
• Sec. 23.951 - General.
• Sec. 23.953 - Fuel system independence.
• Sec. 23.954 - Fuel system lightning protection.
• Sec. 23.955 - Fuel flow.
• Sec. 23.957 - Flow between interconnected tanks.
• Sec. 23.959 - Unusable fuel supply.
• Sec. 23.961 - Fuel system hot weather operation.
• Sec. 23.963 - Fuel tanks: General.
• Sec. 23.965 - Fuel tank tests.
• Sec. 23.967 - Fuel tank installation.
• Sec. 23.969 - Fuel tank expansion space.
• Sec. 23.971 - Fuel tank sump.
• Sec. 23.973 - Fuel tank filler connection.
• Sec. 23.975 - Fuel tank vents and carburetor vapor vents.
• Sec. 23.977 - Fuel tank outlet.
• Sec. 23.979 - Pressure fueling systems.
• Sec. 23.991 - Fuel pumps.
• Sec. 23.993 - Fuel system lines and fittings.
• Sec. 23.994 - Fuel system components.
• Sec. 23.995 - Fuel valves and controls.
• Sec. 23.997 - Fuel strainer or filter.
• Sec. 23.999 - Fuel system drains.
• Sec. 23.1001 - Fuel jettisoning system.
• Sec. 23.1011 - General.
• Sec. 23.1013 - Oil tanks.
• Sec. 23.1015 - Oil tank tests.
• Sec. 23.1017 - Oil lines and fittings.
• Sec. 23.1019 - Oil strainer or filter.
• Sec. 23.1021 - Oil system drains.
• Sec. 23.1023 - Oil radiators.
• Sec. 23.1027 - Propeller feathering system.
• Sec. 23.1041 - General.
• Sec. 23.1043 - Cooling tests.
• Sec. 23.1045 - Cooling test procedures for turbine engine powered airplanes.
• Sec. 23.1047 - Cooling test procedures for reciprocating engine powered airplanes.
• Sec. 23.1061 - Installation.
• Sec. 23.1063 - Coolant tank tests.
• Sec. 23.1091 - Air induction system.
• Sec. 23.1093 - Induction system icing protection.
• Sec. 23.1095 - Carburetor deicing fluid flow rate.
• Sec. 23.1097 - Carburetor deicing fluid system capacity.
• Sec. 23.1099 - Carburetor deicing fluid system detail design.
• Sec. 23.1101 - Induction air preheater design.
• Sec. 23.1103 - Induction system ducts.
• Sec. 23.1105 - Induction system screens.
• Sec. 23.1107 - Induction system filters.
• Sec. 23.1109 - Turbocharger bleed air system.
• Sec. 23.1111 - Turbine engine bleed air system.
• Sec. 23.1121 - General.
• Sec. 23.1123 - Exhaust system.
• Sec. 23.1125 - Exhaust heat exchangers.
• Sec. 23.1141 - Powerplant controls: General.
• Sec. 23.1142 - Auxiliary power unit controls.
• Sec. 23.1143 - Engine controls.
• Sec. 23.1145 - Ignition switches.
• Sec. 23.1147 - Mixture controls.
• Sec. 23.1149 - Propeller speed and pitch controls.
• Sec. 23.1153 - Propeller feathering controls.
• Sec. 23.1155 - Turbine engine reverse thrust and propeller pitch settings below the flight regime.
• Sec. 23.1157 - Carburetor air temperature controls.
• Sec. 23.1163 - Powerplant accessories.
• Sec. 23.1165 - Engine ignition systems.
• Sec. 23.1181 - Designated fire zones; regions included.
• Sec. 23.1182 - Nacelle areas behind firewalls.
• Sec. 23.1183 - Lines, fittings, and components.
• Sec. 23.1189 - Shutoff means.
• Sec. 23.1191 - Firewalls.
• Sec. 23.1192 - Engine accessory compartment diaphragm.
• Sec. 23.1193 - Cowling and nacelle.
• Sec. 23.1195 - Fire extinguishing systems.
• Sec. 23.1197 - Fire extinguishing agents.
• Sec. 23.1199 - Extinguishing agent containers.
• Sec. 23.1201 - Fire extinguishing systems materials.
• Sec. 23.1203 - Fire detector system.

Subpart F - Equipment



• Sec. 23.1301 - Function and installation.
• Sec. 23.1303 - Flight and navigation instruments.
• Sec. 23.1305 - Powerplant instruments.
• Sec. 23.1307 - Miscellaneous equipment.
• Sec. 23.1309 - Equipment, systems, and installations.
• Sec. 23.1311 - Electronic display instrument systems.
• Sec. 23.1321 - Arrangement and visibility.
• Sec. 23.1322 - Warning, caution, and advisory lights.
• Sec. 23.1323 - Airspeed indicating system.
• Sec. 23.1325 - Static pressure system.
• Sec. 23.1326 - Pitot heat indication systems.
• Sec. 23.1327 - Magnetic direction indicator.
• Sec. 23.1329 - Automatic pilot system.
• Sec. 23.1331 - Instruments using a power source.
• Sec. 23.1335 - Flight director systems.
• Sec. 23.1337 - Powerplant instruments installation.
• Sec. 23.1351 - General.
• Sec. 23.1353 - Storage battery design and installation.
• Sec. 23.1357 - Circuit protective devices.
• Sec. 23.1359 - Electrical system fire protection.
• Sec. 23.1361 - Master switch arrangement.
• Sec. 23.1365 - Electric cables and equipment.
• Sec. 23.1367 - Switches.
• Sec. 23.1381 - Instrument lights.
• Sec. 23.1383 - Taxi and landing lights.
• Sec. 23.1385 - Position light system installation.
• Sec. 23.1387 - Position light system dihedral angles.
• Sec. 23.1389 - Position light distribution and intensities.
• Sec. 23.1391 - Minimum intensities in the horizontal plane of position lights.
• Sec. 23.1393 - Minimum intensities in any vertical plane of position lights.
• Sec. 23.1395 - Maximum intensities in overlapping beams of position lights.
• Sec. 23.1397 - Color specifications.
• Sec. 23.1399 - Riding light.
• Sec. 23.1401 - Anticollision light system.
• Sec. 23.1411 - General.
• Sec. 23.1415 - Ditching equipment.
• Sec. 23.1416 - Pneumatic de-icer boot system.
• Sec. 23.1419 - Ice protection.
• Sec. 23.1431 - Electronic equipment.
• Sec. 23.1435 - Hydraulic systems.
• Sec. 23.1437 - Accessories for multiengine airplanes.
• Sec. 23.1438 - Pressurization and pneumatic systems.
• Sec. 23.1441 - Oxygen equipment and supply.
• Sec. 23.1443 - Minimum mass flow of supplemental oxygen.
• Sec. 23.1445 - Oxygen distribution system.
• Sec. 23.1447 - Equipment standards for oxygen dispensing units.
• Sec. 23.1449 - Means for determining use of oxygen.
• Sec. 23.1450 - Chemical oxygen generators.
• Sec. 23.1451 - Fire protection for oxygen equipment.
• Sec. 23.1453 - Protection of oxygen equipment from rupture.
• Sec. 23.1457 - Cockpit voice recorders.
• Sec. 23.1459 - Flight recorders.
• Sec. 23.1461 - Equipment containing high energy rotors.

Subpart G - Operating Limitations and Information



• Sec. 23.1501 - General.
• Sec. 23.1505 - Airspeed limitations.
• Sec. 23.1507 - Operating maneuvering speed.
• Sec. 23.1511 - Flap extended speed.
• Sec. 23.1513 - Minimum control speed.
• Sec. 23.1519 - Weight and center of gravity.
• Sec. 23.1521 - Powerplant limitations.
• Sec. 23.1522 - Auxiliary power unit limitations.
• Sec. 23.1523 - Minimum flight crew.
• Sec. 23.1524 - Maximum passenger seating configuration.
• Sec. 23.1525 - Kinds of operation.
• Sec. 23.1527 - Maximum operating altitude.
• Sec. 23.1529 - Instructions for Continued Airworthiness.
• Sec. 23.1541 - General.
• Sec. 23.1543 - Instrument markings: General.
• Sec. 23.1545 - Airspeed indicator.
• Sec. 23.1547 - Magnetic direction indicator.
• Sec. 23.1549 - Powerplant and auxiliary power unit instruments.
• Sec. 23.1551 - Oil quantity indicator.
• Sec. 23.1553 - Fuel quantity indicator.
• Sec. 23.1555 - Control markings.
• Sec. 23.1557 - Miscellaneous markings and placards.
• Sec. 23.1559 - Operating limitations placard.
• Sec. 23.1561 - Safety equipment.
• Sec. 23.1563 - Airspeed placards.
• Sec. 23.1567 - Flight maneuver placard.
• Sec. 23.1581 - General.
• Sec. 23.1583 - Operating limitations.
• Sec. 23.1585 - Operating procedures.
• Sec. 23.1587 - Performance information.
• Sec. 23.1589 - Loading information.

Appendices

• Appendix A to Part 23 - Simplified Design Load Criteria
• Appendix C to Part 23 - Basic Landing Conditions
• Appendix D to Part 23 - Wheel Spin-Up and Spring-Back Loads
• Appendix F to Part 23 - Test Procedure
• Appendix G to Part 23 - Instructions for Continued Airworthiness
• Appendix H to Part 23 - Installation of An Automatic Power Reserve (APR) System
• Appendix I to Part 23 - Seaplane Loads