Federal Aviation Regulations

Part 27: Airworthiness standards: Normal category rotorcraft

Federal Aviation Regulations

Subpart A - General


• Sec. 27.1 - Applicability.
• Sec. 27.2 - Special retroactive requirements.

Subpart B - Flight



• Sec. 27.21 - Proof of compliance.
• Sec. 27.25 - Weight limits.
• Sec. 27.27 - Center of gravity limits.
• Sec. 27.29 - Empty weight and corresponding center of gravity.
• Sec. 27.31 - Removable ballast.
• Sec. 27.33 - Main rotor speed and pitch limits.
• Sec. 27.45 - General.
• Sec. 27.51 - Takeoff.
• Sec. 27.65 - Climb: all engines operating.
• Sec. 27.67 - Climb: one engine inoperative.
• Sec. 27.71 - Glide performance.
• Sec. 27.73 - Performance at minimum operating speed.
• Sec. 27.75 - Landing.
• Sec. 27.79 - Limiting height -- speed envelope.
• Sec. 27.141 - General.
• Sec. 27.143 - Controllability and maneuverability.
• Sec. 27.151 - Flight controls.
• Sec. 27.161 - Trim control.
• Sec. 27.171 - Stability: general.
• Sec. 27.173 - Static longitudinal stability.
• Sec. 27.175 - Demonstration of static longitudinal stability.
• Sec. 27.177 - Static directional stability.
• Sec. 27.231 - General.
• Sec. 27.235 - Taxiing condition.
• Sec. 27.239 - Spray characteristics.
• Sec. 27.241 - Ground resonance.
• Sec. 27.251 - Vibration.

Subpart C - Strength Requirements



• Sec. 27.301 - Loads.
• Sec. 27.303 - Factor of safety.
• Sec. 27.305 - Strength and deformation.
• Sec. 27.307 - Proof of structure.
• Sec. 27.309 - Design limitations.
• Sec. 27.321 - General.
• Sec. 27.337 - Limit maneuvering load factor.
• Sec. 27.339 - Resultant limit maneuvering loads.
• Sec. 27.341 - Gust loads.
• Sec. 27.351 - Yawing conditions.
• Sec. 27.361 - Engine torque.
• Sec. 27.391 - General.
• Sec. 27.395 - Control system.
• Sec. 27.397 - Limit pilot forces and torques.
• Sec. 27.399 - Dual control system.
• Sec. 27.411 - Ground clearance: tail rotor guard.
• Sec. 27.427 - Unsymmetrical loads.
• Sec. 27.471 - General.
• Sec. 27.473 - Ground loading conditions and assumptions.
• Sec. 27.475 - Tires and shock absorbers.
• Sec. 27.477 - Landing gear arrangement.
• Sec. 27.479 - Level landing conditions.
• Sec. 27.481 - Tail-down landing conditions.
• Sec. 27.483 - One-wheel landing conditions.
• Sec. 27.485 - Lateral drift landing conditions.
• Sec. 27.493 - Braked roll conditions.
• Sec. 27.497 - Ground loading conditions: landing gear with tail wheels.
• Sec. 27.501 - Ground loading conditions: landing gear with skids.
• Sec. 27.505 - Ski landing conditions.
• Sec. 27.521 - Float landing conditions.
• Sec. 27.547 - Main rotor structure.
• Sec. 27.549 - Fuselage, landing gear, and rotor pylon structures.
• Sec. 27.561 - General.
• Sec. 27.562 - Emergency landing dynamic conditions.
• Sec. 27.563 - Structural ditching provisions.
• Sec. 27.571 - Fatigue evaluation of flight structure.

Subpart D - Design and Construction



• Sec. 27.601 - Design.
• Sec. 27.602 - Critical parts.
• Sec. 27.603 - Materials.
• Sec. 27.605 - Fabrication methods.
• Sec. 27.607 - Fasteners.
• Sec. 27.609 - Protection of structure.
• Sec. 27.610 - Lightning and static electricity protection.
• Sec. 27.611 - Inspection provisions.
• Sec. 27.613 - Material strength properties and design values.
• Sec. 27.619 - Special factors.
• Sec. 27.621 - Casting factors.
• Sec. 27.623 - Bearing factors.
• Sec. 27.625 - Fitting factors.
• Sec. 27.629 - Flutter.
• Sec. 27.653 - Pressure venting and drainage of rotor blades.
• Sec. 27.659 - Mass balance.
• Sec. 27.661 - Rotor blade clearance.
• Sec. 27.663 - Ground resonance prevention means.
• Sec. 27.671 - General.
• Sec. 27.672 - Stability augmentation, automatic, and power-operated systems.
• Sec. 27.673 - Primary flight control.
• Sec. 27.674 - Interconnected controls.
• Sec. 27.675 - Stops.
• Sec. 27.679 - Control system locks.
• Sec. 27.681 - Limit load static tests.
• Sec. 27.683 - Operation tests.
• Sec. 27.685 - Control system details.
• Sec. 27.687 - Spring devices.
• Sec. 27.691 - Autorotation control mechanism.
• Sec. 27.695 - Power boost and power-operated control system.
• Sec. 27.723 - Shock absorption tests.
• Sec. 27.725 - Limit drop test.
• Sec. 27.727 - Reserve energy absorption drop test.
• Sec. 27.729 - Retracting mechanism.
• Sec. 27.731 - Wheels.
• Sec. 27.733 - Tires.
• Sec. 27.735 - Brakes.
• Sec. 27.737 - Skis.
• Sec. 27.751 - Main float buoyancy.
• Sec. 27.753 - Main float design.
• Sec. 27.755 - Hulls.
• Sec. 27.771 - Pilot compartment.
• Sec. 27.773 - Pilot compartment view.
• Sec. 27.775 - Windshields and windows.
• Sec. 27.777 - Cockpit controls.
• Sec. 27.779 - Motion and effect of cockpit controls.
• Sec. 27.783 - Doors.
• Sec. 27.785 - Seats, berths, litters, safety belts, and harnesses.
• Sec. 27.787 - Cargo and baggage compartments.
• Sec. 27.801 - Ditching.
• Sec. 27.805 - Flight crew emergency exits.
• Sec. 27.807 - Emergency exits.
• Sec. 27.831 - Ventilation.
• Sec. 27.833 - Heaters.
• Sec. 27.853 - Compartment interiors.
• Sec. 27.855 - Cargo and baggage compartments.
• Sec. 27.859 - Heating systems.
• Sec. 27.861 - Fire protection of structure, controls, and other parts.
• Sec. 27.863 - Flammable fluid fire protection.
• Sec. 27.865 - External loads.
• Sec. 27.871 - Leveling marks.
• Sec. 27.873 - Ballast provisions.

Subpart E - Powerplant



• Sec. 27.901 - Installation.
• Sec. 27.903 - Engines.
• Sec. 27.907 - Engine vibration.
• Sec. 27.917 - Design.
• Sec. 27.921 - Rotor brake.
• Sec. 27.923 - Rotor drive system and control mechanism tests.
• Sec. 27.927 - Additional tests.
• Sec. 27.931 - Shafting critical speed.
• Sec. 27.935 - Shafting joints.
• Sec. 27.939 - Turbine engine operating characteristics.
• Sec. 27.951 - General.
• Sec. 27.952 - Fuel system crash resistance.
• Sec. 27.953 - Fuel system independence.
• Sec. 27.954 - Fuel system lightning protection.
• Sec. 27.955 - Fuel flow.
• Sec. 27.959 - Unusable fuel supply.
• Sec. 27.961 - Fuel system hot weather operation.
• Sec. 27.963 - Fuel tanks: general.
• Sec. 27.965 - Fuel tank tests.
• Sec. 27.967 - Fuel tank installation.
• Sec. 27.969 - Fuel tank expansion space.
• Sec. 27.971 - Fuel tank sump.
• Sec. 27.973 - Fuel tank filler connection.
• Sec. 27.975 - Fuel tank vents.
• Sec. 27.977 - Fuel tank outlet.
• Sec. 27.991 - Fuel pumps.
• Sec. 27.993 - Fuel system lines and fittings.
• Sec. 27.995 - Fuel valves.
• Sec. 27.997 - Fuel strainer or filter.
• Sec. 27.999 - Fuel system drains.
• Sec. 27.1011 - Engines: General.
• Sec. 27.1013 - Oil tanks.
• Sec. 27.1015 - Oil tank tests.
• Sec. 27.1017 - Oil lines and fittings.
• Sec. 27.1019 - Oil strainer or filter.
• Sec. 27.1021 - Oil system drains.
• Sec. 27.1027 - Transmissions and gearboxes: General.
• Sec. 27.1041 - General.
• Sec. 27.1043 - Cooling tests.
• Sec. 27.1045 - Cooling test procedures.
• Sec. 27.1091 - Air induction.
• Sec. 27.1093 - Induction system icing protection.
• Sec. 27.1121 - General.
• Sec. 27.1123 - Exhaust piping.
• Sec. 27.1141 - Powerplant controls: general.
• Sec. 27.1143 - Engine controls.
• Sec. 27.1145 - Ignition switches.
• Sec. 27.1147 - Mixture controls.
• Sec. 27.1151 - Rotor brake controls.
• Sec. 27.1163 - Powerplant accessories.
• Sec. 27.1183 - Lines, fittings, and components.
• Sec. 27.1185 - Flammable fluids.
• Sec. 27.1187 - Ventilation and drainage.
• Sec. 27.1189 - Shutoff means.
• Sec. 27.1191 - Firewalls.
• Sec. 27.1193 - Cowling and engine compartment covering.
• Sec. 27.1194 - Other surfaces.
• Sec. 27.1195 - Fire detector systems.

Subpart F - Equipment



• Sec. 27.1301 - Function and installation.
• Sec. 27.1303 - Flight and navigation instruments.
• Sec. 27.1305 - Powerplant instruments.
• Sec. 27.1307 - Miscellaneous equipment.
• Sec. 27.1309 - Equipment, systems, and installations.
• Sec. 27.1321 - Arrangement and visibility.
• Sec. 27.1322 - Warning, caution, and advisory lights.
• Sec. 27.1323 - Airspeed indicating system.
• Sec. 27.1325 - Static pressure systems.
• Sec. 27.1327 - Magnetic direction indicator.
• Sec. 27.1329 - Automatic pilot system.
• Sec. 27.1335 - Flight director systems.
• Sec. 27.1337 - Powerplant instruments.
• Sec. 27.1351 - General.
• Sec. 27.1353 - Storage battery design and installation.
• Sec. 27.1357 - Circuit protective devices.
• Sec. 27.1361 - Master switch.
• Sec. 27.1365 - Electric cables.
• Sec. 27.1367 - Switches.
• Sec. 27.1381 - Instrument lights.
• Sec. 27.1383 - Landing lights.
• Sec. 27.1385 - Position light system installation.
• Sec. 27.1387 - Position light system dihedral angles.
• Sec. 27.1389 - Position light distribution and intensities.
• Sec. 27.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.
• Sec. 27.1393 - Minimum intensities in any vertical plane of forward and rear position lights.
• Sec. 27.1395 - Maximum intensities in overlapping beams of forward and rear position lights.
• Sec. 27.1397 - Color specifications.
• Sec. 27.1399 - Riding light.
• Sec. 27.1401 - Anticollision light system.
• Sec. 27.1411 - General.
• Sec. 27.1413 - Safety belts.
• Sec. 27.1415 - Ditching equipment.
• Sec. 27.1419 - Ice protection.
• Sec. 27.1435 - Hydraulic systems.
• Sec. 27.1457 - Cockpit voice recorders.
• Sec. 27.1459 - Flight recorders.
• Sec. 27.1461 - Equipment containing high energy rotors.

Subpart G - Operating Limitations and Information



• Sec. 27.1501 - General.
• Sec. 27.1503 - Airspeed limitations: general.
• Sec. 27.1505 - Never-exceed speed.
• Sec. 27.1509 - Rotor speed.
• Sec. 27.1519 - Weight and center of gravity.
• Sec. 27.1521 - Powerplant limitations.
• Sec. 27.1523 - Minimum flight crew.
• Sec. 27.1525 - Kinds of operations.
• Sec. 27.1527 - Maximum operating altitude.
• Sec. 27.1529 - Instructions for Continued Airworthiness.
• Sec. 27.1541 - General.
• Sec. 27.1543 - Instrument markings: general.
• Sec. 27.1545 - Airspeed indicator.
• Sec. 27.1547 - Magnetic direction indicator.
• Sec. 27.1549 - Powerplant instruments.
• Sec. 27.1551 - Oil quantity indicator.
• Sec. 27.1553 - Fuel quantity indicator.
• Sec. 27.1555 - Control markings.
• Sec. 27.1557 - Miscellaneous markings and placards.
• Sec. 27.1559 - Limitations placard.
• Sec. 27.1561 - Safety equipment.
• Sec. 27.1565 - Tail rotor.
• Sec. 27.1581 - General.
• Sec. 27.1583 - Operating limitations.
• Sec. 27.1585 - Operating procedures.
• Sec. 27.1587 - Performance information.
• Sec. 27.1589 - Loading information.

Appendices

• Appendix A to Part 27 - Instructions for Continued Airworthiness
• Appendix B to Part 27 - Airworthiness Criteria for Helicopter Instrument Flight
• Appendix C to Part 27 - Criteria for Category A