RC Glossary of Terms

Expanded Scale Voltmeter (ESV)

Device used to read the battery voltage of the on-board battery pack or transmitter battery pack under load.

Exponential(EXPO)

This radio function allows the modeler to adjust the sensitivity of the control towards the center. This will make the small stick motions very precise, while longer stick movement moves the servo arm at a proportional rate.

EZ Connector

A Dubro product name generically used to describe a fitting that is attached to a control horn or servo arm by means of a pin and a snap connector. A wire or cable pushrod slides through a hole in the connector and is secured by means of a set screw. (personally, I prefer the good ol' z bend)

Fades

The term used to describe data that does not reach the receiver. Dual Link minimizes this possibility.

Failsafe

A PCM function which moves servos to a pre-programmed position if transmitter signal is lost or corrupted.

Fairing

A component used to create a streamlined intersection between two or more other components or to cover a component to reduce drag.

FHSS

Frequency Hopping Spread Spectrum. These systems usually transmit a narrow band signal and rapidly jump through a fixed set of frequencies, spending a few milliseconds on each frequency.

Field Charger

A fast battery charger designed to work from a 12-volt power source, such as a car battery.

Figure 9

A loop that is terminated by a dive into the ground. This maneuver is entertaining for all pilots present except the one who performs the maneuver.

Flaps

Hinged control surface located at the trailing edge of the wing inboard of the ailerons. The flaps are lowered to produce more aerodynamic lift from the wing, allowing a slower takeoff and landing speed. Flaps are often found on scale models, but usually not on basic trainers.

Flare

A gradual increase in pitch angle to bleed off excess airspeed just before landing.

Flight Box

A special box used to hold and transport all equipment used at the flying field.

Flight Log

Flight Log is in reference to a screen that reports the signal and reception quality between your Spektrum Transmitter and telemetry capable receiver. This is reported to the user in real-time on compatible Spektrum transmitters.

Flight Modes

A function of your transmitter to change flight characteristics with the flip of a switch. This can be customized to control many aspects of flight, such as rates, control mixing and stability modes.

Flight Pack (or Airborne Pack)

All of the radio equipment installed in the airplane, i.e., Receiver, Servos, Battery, Switch Harness.

Flutter

A phenomenon whereby the elevator or aileron control surface begins to oscillate violently in flight. This can sometimes cause the surface to break away from the aircraft and cause a crash. There are many reasons for this, but the most common are excessive hinge gap or excessive "slop" in the pushrod connections and control horns. If you ever hear a low-pitched buzzing sound, reduce throttle and land immediately.

FM

Frequency Modulation. This describes the mode of transmission of radio signal from transmitter to receiver.

Forward Programming

Spektrum technology that allows the configuration of Smart devices (receivers, etc.) wirelessly and directly from the transmitter. No separate computer or mobile device is needed for setup and adjustments.

Four Stroke (Four Cycle)

Although a 4-stroke engine has less power than a 2-stroke engine of comparable size, there are advantages to 4-stroke engines. They do not require a muffler and are often quieter than most 2-strokes are with a muffler. They can swing a bigger prop than the same size 2-stroke engine. This is an asset in the large, slow-flying aerobatic and scale models where 4-stroke engines are usually mounted. Lastly, the fuel economy is better.

Frame Loss

The simultaneous loss of information to both antennas in the aircraft system.

Frame Rate

The time interval at which the servo data is updated on the receiver.

Frequency

The specific channel or Radio Frequency spectrum that a radio broadcast on. In a traditional RC radio, the transmission crystal resonates when voltage is applied; the rate of this resonation determines the frequency that is broadcast on.

Frequency Control

The FCC has allowed the 72MHz band to be used for R/C aircraft operations. This band is divided up into many different channels in which you can choose a radio system. You should be aware that certain areas have frequencies in which there is pager interference. This is why it is always a wise move to check with your local hobby shop to find out any channels that may be troublesome in the area you wish to fly.

Frequency Module

A frequency module plugs into the transmitter and enables you to change the channel number your radio broadcasts on.

Fuselage

The main body of the airplane.

Gain

Typically referred to in gyros, gain is the feedback correction authority used to counteract the rate of motions in a gyro.

Glide Ratio

Momentary radio problem that never happens unless you are over trees or a swamp ;)

Grease-In

A very smooth, gentle landing without a hint of a bounce.

Ground Effect

The cushion of air that the model rides on when close to the ground. This will decrease the amount of elevator needed to maintain a constant altitude when near the ground/landing.

GUID

Globally Unique Identification Code. Each individual module or radio is factory programmed with its own unique serial code. In the binding process, the receiver is programmed to only recognize the GUID code of one specific radio or module.