Glossary For Model Helicopters
When you are learning to fly remote control helicopters there are a lot of terms that you are going to come across and this RC helicopter glossary will help you to understand exactly what they mean.
3D flying
This term means using two maneuvers at once when flying RC helicopters.
540 Stall
This means doing a high speed climb which is then followed by a 540 degree pirouette as your RC helicopter stops climbing.
Airfoils
This is the shape of a wing which produces lift.
ARF
This is a prefabricated RC helicopter model that is almost ready to fly.
Autorotation
This is what is used if your RC helicopter engine should fail.
ATV
This is an adjustment that you will find on transmitters that will allow you to adjust the maximum throw of a servo.
Base Load Antenna
This is a short whip antenna that is about 6 inches long and is used instead of the long antenna that comes with the receiver.
Bell and Hiller
This is a the control system used for RC helicopters that allows the pitch of the blades to change with the aid of paddles which takes load off the control system.
Boom Strike
One of the most common events experiences by new RC helicopter pilots where they push their RC helicopter into the ground. This is where the rotor blades bend and one of them makes contact with the boom.
Buddy Box
This is similar to having dual controls and is perfect for beginners. This is where two transmitters are wired together.
CA Glue
This is the glue that is used when building RC helicopter models.
CG – Centre of Gravity
This is the point at which the RC helicopter balances and it is critical to how your RC helicopter will react in the air.For more on the topic of centre of gravity CLICK HERE
Channels
There are two types of channels when it comes to RC helicopters. One is the channel that the Tx transmits on and the other is how many control surfaces that a Tx can control.
Clutch
RC helicopters use a clutch so that their engines can be idle without the rotor blades spinning.
Centrifugal Force
This is the pulling force that the RC helicopter applies to the blades while they are spinning.
Collective – Variable Pitch
This is the control that adjusts the pitch of the RC helicopter rotor blades. This causes the RC helicopter to ascend or descend without needed to change the rotor RPMs.
Cyclic
This describes the controls that adjust the horizontal attitude of the RC helicopter.
Drag
This describes the force that air pushes back onto a moving object when resisting its movement.
Dual Rates
This is a feature of some Tx models that allows a person to flip a switch to make the controls of their RC helicopter more or less sensitive.
ESC
This is the electronic speed control which takes the power from the battery pack and the signal from the receiver and sends power to the RC helicopter motor.
Exponential
This is a feature of some Tx models that will allow you to program in different control sensitivities to your RC helicopter.
Failsafe
This is a feature of some Tx and Rx models that support PCM. The failsafe is used so that the servo’s go to a predefined position if the signal is lost.
Feathering Shaft
This is a rod that helps to support the rotor blades and give them more rigid strength.
Fixed Pitch
This is a term that describes an RC helicopter that has no collective adjustments meaning that you control the height strictly with the rpm’s of the rotor blades.
Gasser
This is a term used to describe RC helicopters that run on gasoline.
Governor
This is a device that is used to automatically hold the rotor RPM constant.
Glow Fuel
This is a special kind of fuel that RC helicopters use.
Gyro
This is a device that is used to help stabilize the yaw of an RC helicopter. For more detailed information > Click Here
Heli Transmitter
This is a transmitter that has special features for flying RC helicopters.
Hovering
This is the process of flying your RC helicopter but not actually going anywhere.
Hydraulic Lock
This is where your RC helicopter cylinder has filled with fuel and cannot complete a rotation.
Idle Up
This is a feature on most RC helicopter transmitters that stops the throttle from falling below a minimum setting.
Jesus Bolt
There are two of these on most RC helicopters and they hold the main mast to the frame and the head to the mast.
Too Lean
This means that the fuel to air ratio of your RC helicopter is too low and your engine will run hot and can be damaged very quickly.
Mixing
This is a term used to describe the function of many RC helicopter transmitters. It allows on control movement to affect more than one control surface at a time.
Nose-In
This is a term that describes hovering or maneuvering with the nose of the RC helicopter pointed at the person controlling it.
Paddles
These are the short stubby blades on the end of the two rods opposite the rotor blades of the RC helicopter.
Peak Charger
A peak charger will automatically shut off when your RC helicopter battery is fully charged.
Pirouette
This is a maneuver that is described as a high yaw rate of an RC helicopter when the tail spins around the canopy one or more times.
Pitch Meter
This is a measuring device that is used to check the varying pitch settings of your RC helicopter rotor blades and paddles.
Relative Wind
This is the direction that the wind is hitting the RC helicopters rotor blades also taking into consideration flapping and retreating blades.
Retreating Blade Stall
This is a very dangerous situation which can result in your losing control of your RC helicopter. This is where when you are in fast flight the blade that is flying towards the RC helicopter tail looses enough airspeed to generate lift.
Revolution Mixing
This is a mixing function on a transmitter which lets you program a throttle to rudder mix on your RC helicopter so that as you add more power the transmitter automatically adds more rudder to compensate for the increase in torque.
Rotary Wing Platform
This is the term that describes the main rotor blades of an RC helicopter.
Rotational Velocities
This term describes how the airspeed over the tips of the RC helicopter blades is different than that over the other parts of the blade.
Rx
This stands for the receiver which is the portion of the radio system that is mounted in the RC helicopter and it adjusts the servos according to the transmission from the Tx.
Servo
This is a device that can turn a lever arm one way or the other with many points between the two extremes. Servos are the physical link between the control system on a remote control helicopter and the main rotor blades. They translate the control inputs into mechanical movements. Servos are connected to a helicopter’s swashplate using links and rods. For more information about servos > Click Here
Stabilizers
There are two stabilizers, the horizontal and the vertical. These help the RC helicopter to weathervane so that while in forward flight the RC helicopter points into the wind.
Swash Plate
This is a device that the control arm spins around so that the pitch of the blades can be changed depending on their relative position to the RC helicopter.
Throttle Curve – Pitch Curve – Programmable Points
With this you can change the way the servos move as you move the stick. There are usually different curve settings for each idle up mode. This allows you to fly your RC helicopter upside down.
Throttle Hold
This is a feature that comes with most RC helicopter transmitter models. This switch can be used as a safety switch.
TR
This is short for tail rotor.
Training Gear
This is larger landing gear that you can get for your RC helicopter which is especially useful for beginners so they don’t damage their RC helicopters when learning to hover. For more > Click Here
Transitional Life
When you are in forward flight the spinning rotor disc produces more lift than in a hover.
Transverse Flow Effect
When you are in a slow forward flight, wind in the rear part of the disk enters at a lower angle of attack due to the leading edge of the disk pulling air down. This results in vibrations.
Tx
This is an abbreviation of the RC helicopter remote control unit or transmitter.
Washout
A washout is a twist in your RC helicopter blade so that part of it is at a different angle of attack than the rest.
Woof And Poor
This is the sound that the rotor blades of the RC helicopter make when they go wildly out of track.
Yaw Rate
This is a term that describes the control input of a heading hold type gyro.
Yaw – Pitch – Roll
This is a term that describes the change of attitude of an RC helicopter. Yaw is the movement about the vertical axis. Pitch describes leaning forward or backwards and roll describes leaning to the left or the right. For more information about Yaw control > Click Here