| Name | Description | Category |
| Advancing blade | The blade in the section of the rotordisc where rotation is in the same direction as the movement of the helicopter. | Rotor system |
| Aerofoil | Any shape designed to obtain a useful reaction from the air through which it moves. | Aerodynamics |
| Airfoil | See Aerofoil. 'Aerofoil' is English; 'Airfoil' is American English. | Aerodynamics |
| Fuselage | The frame and skin of an aircraft. | General aviation |
| Hull | See Fuselage | General aviation |
| Airframe | See Fuselage | General aviation |
| Oleo | See oleo-pneumatic strut | Engineering |
| Oleo-pneumatic strut | A device that dampens a displacement by pushing oil through a small orifice every time the length of the strut changes. | Engineering |
| Composite materials | A composite material (composite for short) is a material which is engineered from two distinct materials, the substrate and the resin. The substrate is usually a fibre structure, and the resin is a polymer that simply holds the fibres in place. Commonly used composites are fibreglass, carbon fibre, and kevlar. | Engineering |
| Lead | Consider a rotor that rotates with constant angular velocity. When, sometime during one revolution, the blade momentarily moves more quickly, it is said to lead, as it will move slightly more forwards than would normally be the case. | Rotor system |
| Lag | Consider a rotor that rotates with constant angular velocity. When, sometime during one revolution, the blade momentarily moves at a lower speed, the blade is said to lag, as it will move slightly more backwards than would normally be the case. | Rotor system |
| Flap | A rotor blade can flap up or down at some point in one revolution. This displacement is orthogonal to the plane of rotation. | Rotor system |
| Sampling rate | The frequency at which a measurement of an analogue signal is made and represented as a digital sequence. | Miscellaneous |
| Payload | The useful load that can be carried by an aircraft. It is defined as the difference of the gross weight of the helicopter minus empty weight, crew and fuel. | General aviation |
| Blade angle | Angle between a blade's chord line and the plane of rotation. | Aerodynamics |
| Chord (line) | Chord line. The straight line between the blades leading edge and it trailing edge. | Aerodynamics |
| Rotor disc | Imaginary disc spawn between the rotating rotortips. | Rotor system |
| Cyclic | Flight control that controls the direction of flight by controlling the rotordisc orientation. | Flight controls |
| Collective | Flight control that controls the amount of lift generated by the rotordisc. | Flight controls |
| Pedals | Flight control that controls the helicopter's yaw by controlling tailrotor thrust. | Flight controls |
| Pitch angle | See Blade angle | Aerodynamics |
| Feathering | Rotation of a blade around its (feathering) axis. Feathering results in blade angle change. | Rotor system |
| Alternator | Device that generates electrical power. | Miscellaneous |
| Induced flow | The airflow that exists solely as a result of the airmass that is forced down by rotoraction. | Aerodynamics |
| Drag | The resistance of an aerodynamic body moving through air. Drag is a resistance force and acts in the opposite direction of airmovement. | Aerodynamics |
| Induced drag | The reaction force generated by an airfoil in the direction of the relative airflow. | Aerodynamics |
| Profile drag | The amount of drag due to the airfoil shape and material. | Aerodynamics |
| Inflow angle | The angle between the RAF (Relative Air Flow) vector and the plane of rotation. | Aerodynamics |
| Angle of attack | The angle between the RAF (Relative Air Flow) vector and the blade's chord line. | Aerodynamics |
| Relative airflow | The Relative Air Flow (RAF) is the airflow with speed and direction, relative to the airfoil. | Aerodynamics |
|