- Aerobatic – a maneuver or a series of maneuvers in the air with your aircraft (ex. loops, rolls, spins.)
- Adverse yaw – When an airplane is turned using only the ailerons, drag from the lowered aileron is more than that of the raised aileron. The extra drag makes the airplane yaw in the opposite direction of where the pilot intended to fly.
- Ailerons – the moving section of the trailing edge of the aircraft’s wing, located towards the outer end. Ailerons come in pairs, (left and right) and always work in opposite directions to each other (one up, one down). When used, they cause the aircraft to roll to the left or right.
- Airfoil – the cross-section shape of an aircraft’s wing. Another common spelling is aerofoil.
- Altitude – the vertical distance between your aircraft and the ground (usually expressed in feet).
- Angle of Attack – the angle of the wing (when viewed from the wings tip, facing in towards the body of the aircraft) in relation to the horizontal airflow when the aircraft is flying.
- Almost-Ready-To-Fly (ARF) – a model aircraft kit, typically 90% pre-built, that requires moderate building skills and typically does not come with an engine or electronics.
- Barrel roll – an aerobatic maneuver that involves the aircraft following the twist of a large imaginary corkscrew (horizontal) through the air.
- Brushless motor – a type of electric motor (versus a brushed motor) used in electric aircraft. They are categorized in as inrunners or outrunners.
- Buddy Box – a training aid where the student’s transmitter is attached via cable to the instructor’s transmitter. The student has complete control over the model, but at the flick of a switch the instructor can take control.
- Bulkhead – the foremost structural formation of your aircraft, on to which the engine is mounted. Also commonly knows as a Firewall.
- CA glue (cyanoacrylate) – An adhesive/glue that cures rapidly. Commonly called ‘super glue’.
- Center of Gravity (CG) – the aircraft’s point of balance. As a general rule of thumb, it’s found approximately 1/3 of the way back from the leading edge of the wing.
- Channel – the number of channels (i.e. ‘controlable’ movable objects (ex. rudder, landing gear, throttle, etc.) that a model can have. It also is used to describe the radio frequency which you’re transmitter is using (ex. Channel 36).
- Chicken stick – a dowel or rod with a rubber sleeve that you use to start a glow motor (by hand) through flicking the propeller around with the stick.
- Control surface(s) – a collective term for the rudder, elevator and ailerons of an aircraft.
- Crosswind – when the wind is blowing at, or approximately, 90 degrees to your line of flight, take off or landing.
- Crystal – physically a small crystal that determines which channel number your radio will be using. Both transmitters (Tx) and receivers (Rx) need to have an identically matching crystal numbers for the radio set to function properly.
- Dead stick – a term used when an aircraft’s motor dies in mid-air. “They made a dead stick landing.”
- Dihedral – the upward angle (or ‘V’ shape) of your aircraft’s wings when viewed from the front of the plane. It is this upward sweep that gives the airplane its added stability.
- Disorientation – when you lose sight of which way up or down your aircraft is flying.
- Drag – the force that is created by the movement of the aircraft through the air, on the air immediately surrounding the plane. High drag means that the model has to work harder to cut through the air. Low drag, means the opposite.
- DSM2 – a type of technology used in the latest Spread Spectrum / 2.4GHz radio control systems.
- Dual rates – a feature of many transmitter radio systems, whereby the control surface deflection can be reduced while still maintaining full movement of the transmitter sticks. With dual rates enabled, the aircraft is less sensitive to control inputs.
- EDF (Electric Ducted Fan) – An electric ducted fan ‘unit’ is a propulsion arrangement whereby a fan, which is a type of propeller, is mounted within a cylindrical shroud or duct.
- Electric starter – an electric motor with a special rubber cup on the end that you place over the spinner to turn the motor over until it starts.
- Elevator – the moving section at the rear of the horizontal stabilizer, or tailplane, that controls the pitch of the aircraft.
- Elevons – when elevator and aileron control is made by the same control surface, this surface is called an elevon(s). Only possible with mixing capabilities on a transmitter radio.
- Electronic Speed Control (ESC) – an electronic device that monitors and delivers the appropriate amount of power from a battery pack to an electric motor.
- Field box – a tool box you take to the flying field. It contains all your flying accessories, tools, fuel, etc.
- Field equipment – accessories and equipment that you take to the field in your field box.
- Fin – also called the vertical stabilizer, it’s the vertical surface at the rear of the aircraft used to stabilize the plane in flight.
- Flaps – moving sections of the trailing edge of the wing, on the inside of the ailerons. Used to create more lift at slower flying speeds.
- Flaperons – a single control surface on the trailing edge of each wing that does the job of flaps and ailerons. A radio system with control mixing capability is needed to have flaperons.
- Flare – the action taken a few feet above the ground when landing, to reduce the approach angle and slow the rate of descent.
- Four-Stroke (4-Stroke) Engine – An engine in which the piston travels up and down twice to achieve combustion. Produces more torque (power) than 2-stroke engines of similar size, as well as a more “scale” sound, greater economy and the ability to swing bigger props. Less common than 2-stroke engines, but more often used in large- or giant-scale airplanes. Where engine requirements for a kit are listed, 4-stroke engines are usually the second range listed and marked as such. See also Two-Stroke Engine.
- Frequency – all radio control gear works on frequencies.
- Fuel lock – when your glow engine is flooded with excess fuel inside the engine and prevents you from being able to turn over or “flick” the prop. It usually happens if you’ve over-primed the engine.
- Fuselage – the main body of an aircraft, excluding wings, tail and everything else.
- Glow plug – sits in the motor’s cylinder head and contains an electrical filament that glows red hot to ignite the fuel/air mixture in the combustion chamber.
- Glow plug igniter – used to pre-ignite the glow plug when you are starting up your engine.
- Horizontal stabilizer – also called the tailplane. It is the horizontal surface at the back of the fuselage, to which the elevators are attached.
- Inrunner – a type of brushless motor, where only the motor shaft rotates within the motor casing, as in a normal brushed motor.
- Landing gear – also called the undercarriage. Refers to all wheels and associated bits. Landing gear can be fixed or retractable up into the underside of the wing or fuselage (called ‘retracts’, usually only found on models with 5 channels or more).
- Leading edge – the front edge(s) of an aircraft’s wing, tailplane or rudder.
- Lift – the force created by the forward motion of the aircraft’s wing. Air pressure on top of the wing is less than the pressure below the wing and so the wing, along with the rest of the model, is pushed upwards.
- Li-Po (Lithium Ion Polymer) – the most modern kind of battery pack being used in electric aircraft today. They provide enormous amounts of power for their size, especially when used in conjunction with a brushless motor.
- Loop – an aerobatic maneuver whereby the aircraft flies a vertical circle in the air
- Mid-air – term used to describe the two or more models making physical contact with each other while in flight. “They had a mid-air collision.”
- Mixing – the ability to combine two different radio / aircraft movement functions into one (ex. Elevator movement and aileron movement is combined into the same transmitter stick movement(s)).
- NiCD (Nickel Cadmium) – A form of rechargeable battery used in radio control gear as well as motor battery packs.
- NiMH (Nickel Metal Hydride) – A form of rechargeable battery used in radio control gear as well as motor battery packs.
- Nitro Fuel (Nitro Methane) – the “power” ingredient in glow fuel. Nitro fuel = glow fuel.
- Outrunner – the other type of brushless motor, where the outer shell, or ‘can’, of the motor rotates with the shaft. The extra inertia produces more torque, so outrunners are more powerful than inrunners.
- Park Flier / Park Flier – a name given to an aircraft that can be safely flown in a public park, school yard, parking lot, sports field, etc.
- Pitch attitude – the upward or downward angle of the aircraft in relation to the horizontal, when viewed from the side. Pitch is controlled by the elevators.
- Pitch – the angle of a wing or propeller blade in relation to the airflow over it. The pitch angle of a moving wing or blade is known as Angle of Attack.
- Plug-and-Play (PNP) – model aircraft kits that require only a transmitter and receiver to complete.
- Pre-flight – an essential “check-list” procedure that you carry out immediately before flight. “We performed all of our pre-flight, and are ready to take off.”
- Priming – the action of introducing fuel into the engine prior to starting it. Over-priming often causes fuel lock.
- Pushrods – Physical rods, frequently metal, that connect servos to movable parts of the plane.
- Radio failure/interference – the uncontrollable actions of the model, usually caused by an electronic interference or power loss to your transmitter and receiver.
- Radio signals – the invisible messages that pass from transmitter to receiver, telling the model what to do.
- Range check – a pre-flight test of your radio gear done by standing 90 to 100 feet away from your model (engine/motor off), moving your receiver sticks, and ensuring your control surfaces are moving as well.
- RC or R/C – abbreviation for Radio Control. Often used in conjunction with “Remote Control”.
- R/C flight simulator – a computer based training aid that allows you practice flying radio control. Also known as a “Flight Sim”.
- Receiver (Rx) – the radio component that receives the transmitter signal and relays its command to the servos.
- Retracts – abbreviation for ‘retractable undercarriage’, which is typically landing gear that folds up into the aircraft’s wings or fuselage.
- Roll – the rotational movement of an aircraft about its longitudinal axis. Also an aerobatic maneuver whereby the aircraft is rolled about its longitudinal axis through 360 degrees, while trying to keep the thing in a straight line.
- RPM (rpm) – Revolutions Per Minute. Used to describe an engine’s operating range.
- Ready-To-Fly (RTF) – a model kit that comes fully assembled with included radio gear (receiver and transmitter).
- Rudder – the moving section on the back half of the fin. Used to control the aircraft’s yaw.
- Servo – a small electronic device (mounted on the aircraft body) used to create movement to the control surfaces of your aircraft.
- Servo reverse – a feature on radio systems whereby the movement of a servo can be reversed (Telling it to move “up” instead of “down”).
- Slow Flier – another name for a Park Flyer or an aircraft that is flown indoors.
- Spin – an aerobatic maneuver whereby the aircraft is flown vertically down towards the ground, while being made to roll.
- Spinner – the cone-shaped object that covers the center of the propeller.
- Sport aircraft – a general term for model aircraft that can are used for training of aerobatic maneuvers.
- Spread spectrum – a technology term for radio control systems that is based on the 2.4GHz frequency band.
- Stall – a phenomenon that occurs when when the aircraft flying speed gets too low and the necessary amount of lift needed to hold the model in the air is lost, thus causing the aircraft to suddenly “drop”.
- Stall turn – an aerobatic maneuver whereby the aircraft is put into a vertical climb, power is reduced and full rudder is applied. The aircraft should stop in mid-air and turn through 180 degrees, thus facing the ground, in the direction that the rudder was applied.
- Straight and level – when your rc aircraft is flying in a straight line, with no fluctuation in altitude. A well trimmed aircraft should fly straight and level with the transmitter sticks in their central positions.
- Take off – the action of accelerating your aircraft along the ground until flying speed is reached, and the aircraft is airborne.
- Taildragger – an aircraft that has 2 main wheels and a small tail wheel.
- Tail wind – when the wind is blowing in the same direction as your plane is flying, taking off or landing. Flying with a tail wind not only increases the plane’s airspeed, but also its stalling speed.
- Thrust – the force that is generated by the spinning propeller of the aircraft, and pushes the model through the air.
- Trailing edge – the rear edge of the wing, tailplane or rudder.
- Trainer – an aircraft that has been designed for learning to fly on. Usually trainers are high wing, with plenty of dihedral.
- Transmitter (Tx) – the part of a radio system that a pilot operates to transmit control signals to a receiver.
- Trim – A term with two meanings. Trim (in relation to finishing) refers to additional decorative elements (graphics, lines, etc) added to an existing finish. Trim (in relation to flying) refers to making mechanical adjustments that will allow the plane to fly predictably and well.
- Tricycle (Landing) Gear – Landing gear that includes two main gears (usually located under the wings) and a nose wheel. Often found on trainers, it holds the plane roughly level and provides very stable ground handling.
- Two-Stroke Engine – The most common type of glow engine, one in which the piston travels up and down once to achieve combustion. Where engine requirements for a plane are listed, the 2-stroke range is usually the first (or only) range listed. See also Four-Stroke Engine.
- Vertical stabilizer – the vertical surface at the rear of the aircraft used to stabilize the plane in flight (same as ‘fin’; above).
- Windsock – a large material cone-shaped tube, mounted on a tall pole at the flying field, that indicates the direction of the wind. Important because of an aircraft’s need to be taken off and landed into the wind where possible.
- Wingspan – the overall length of the wing, from tip to tip. Wingspan is the primary measurement when referring to an aircraft’s size, and it’s usually stated in inches.
- Yaw – the rotational movement of an aircraft about its vertical axis, controlled by the rudder.