RC Glossary of Terms

Crow

See "Butterfly".

Crucifix Tail

A stabilizer that is mounted partway up the fin. This is a compromise between the conventional tail and the T-tail, combining some of the major advantages of both.

Datum

(aka Datum Line) A reference line from which measurements are taken.

Dead Stick

Slang term for a landing without engine power. An example: "I ran out of fuel at 50 feet and had to dead stick".

Decalage

The angular difference of the wing incidence and the horizontal stabilizer incidence.

Delta Wing

Delta Wing aircraft have one large wing with a sharply swept leading edge and a straight trailing edge. The result is a wing that looks like the Greek letter Delta (Δ). There is usually no horizontal stabilizer with conventional elevators. Delta Wing aircraft use their ailerons for both pitch and roll control.

Dethermalizer

A device used to spoil the trim of an aircraft and cause it to sink. A dethermalizer is most commonly used on free-flight endurance models to prevent them from flying away.

Detonation

Or pre-ignition is a potentially engine-damaging condition in which part of the fuel/air mixture ignites before the piston is at top dead center (TDC). Pre-ignition is a result of poor ignition timing and can be heard as 'engine knock'. In nitro engines, the proper combination of glow plug and nitro content will prevent this.

Differential Throw

Ailerons that are set up to deflect more in the upward direction than downward are said to have Differential Throw. The purpose is to counteract Adverse Yaw.

Dihedral

The upward inclination of an aircraft wing in relation to the lateral axis. A wing with dihedral is more stable and will tend to level itself from banked flight due to the higher wing having less lift than the lower wing.

Dipole

3rd generation Frequency Hopping Spektrum 2.4 gHz protocol that offers superior radio frequency link security and the ability for over 100 systems to operate interference-free simultaneously.

Direct Servo Control (DSC)

This radio feature permits you to check servo operation without broadcasting a radio signal. A cable connects the transmitter to the receiver. Direct servo control is very useful for on-the-ground control checks.

Disk

Term describing the shape of the rotary wing or propeller formed by the spinning blades.

Doublers

A second piece of balsa or plywood added to the fuselage side to enhance strength.

Down Thrust

Downward angle of the engine relative to the centerline of the airplane. Down thrust helps overcome the normal climbing tendency caused by the torque of the engine.

Drag

Air resistance that slows the model.

DSM

Digital Spectrum Modulation; DSM is the 2.4GHz technology that makes Spektrum possible.

DSM2

The second generation of Digital Spread Modulation. DSM2 offers significantly reduced latency and a faster response time than any brand of 27, 75, or 72MHz PCM system.

DSMR

Spektrum surface "Racing" protocol that delivers reduced latency, superior Radio Frequency link security, and the ability for over 100 systems to operate interference-free simultaneously.

DSMX

3rd generation Frequency Hopping Spektrum 2.4 gHz protocol that offers superior radio frequency link security and the ability for over 100 systems to operate interference-free simultaneously.

DSSS

Direct Sequence Spread Spectrum. DSSS broadcasts on the 2.4GHz frequency band and generates a wide signal on a single frequency.

Dual Conversion

A dual conversion receiver filters the incoming radio signal from the transmitter through two separate and distinct electronic filters. This “double filtering” helps the receiver to ignore unwanted signals that are close to the frequency being used. This is NOT protection against another transmitter sending a signal on the SAME frequency. Instead, it is protection against other transmitters transmitting on frequencies that are close to the one being used.

Dual Link

Spektrum designed architecture that provides increased Radio Frequency link diversity. This combined with DSM2 is what makes the full range system possible.

Dual Rates

Radio function used to adjust control sensitivity.

Electric Starter

A hand-held electric motor used for starting a model airplane engine. Usually powered by a 12-volt battery.

Elevator

The pitch-control surface.

Empennage

The vertical and horizontal tail surfaces of an airplane.

Endpoint Adjustment

This radio feature adjusts the length of servo travel in one direction (a single channel will have adjustments for two endpoints). If your plane rolls faster one way than the other, endpoint adjustments can correct the problem.

Epoxy

A two-part resin/hardener glue that is extremely strong. It is generally available in 6 and 30-minute formulas. Used for critical points in the aircraft where high strength is necessary.

ESC (electronic speed control)

The unit that controls the rpm of an electric motor.