RC Glossary of Terms

Stab

Horizontal stabilizer.

Stall

When the air flowing over the wing cannot produce enough lift to support the weight of the model. This can happen if the modeler flies too slowly, or if the wing is at a too-high angle to the incoming airflow. If the wing is at a too-high angle to the incoming airflow, then it cannot flow over the wing properly to develop lift.

Stall Turn

The maneuver in which the model is flown to a point where the rotor disk/main wing is vertical, reaches an apex/stalls, then is turned about the yaw axis to continue in a nose-forward/down attitude, and is then returned to horizontal flight.

Straight Flight

The model must be brought exactly parallel to the flight path and flown in an absolutely straight and level path. Inverted Flight: The model flies along a straight line inverted.

Sub-Trim

This is a trim function on many computer radios, allowing trim adjustments during setup while still allowing the full trim function in flight.

T-tail

Refers to a stabilizer that is mounted on top of the fin. This brings the stabilizer away from the turbulent airflow of the wing and makes pitch control more responsive. It also gets the stabilizer out of harm's way when landing on rough terrain. The T-tail construction is usually more fragile than the conventional tail and is more difficult to build.

Tail Dragger

This refers to the landing gear configuration where the main landing gear with two wheels is placed forward of the center of gravity and one small wheel, called a "tail wheel," is mounted under the tail of the aircraft.

Tail Wheel

The small wheel at the tail of the airplane. This is found on the type of airplane that has the two large wheels in the front and the small one in the rear. The airplane sits on its tail.

Take off

The model must stand still on the ground with the engine(s) running, without being held. The throttle is then smoothly, not suddenly, advanced. After the takeoff roll has started, the nose wheel lifts off the ground (tail wheel for a conventional gear airplane), and the aircraft assumes a climb attitude while still rolling on its main wheels. When the aircraft reaches flying speed it should gently lift off the ground and climb at a gradual angle. The aircraft must not deviate in heading during the takeoff. The takeoff is completed when the model is approximately 2 meters (6 1/2 feet) from the ground.

TE

Trailing Edge (rear).

Telementry

Provides real time information regarding model parameters (like battery charge condition, speed, radio link condition, etc.) to the pilot or driver typically through the transmitter via on screen information, audio tone, or voice prompts.

Throttle Cut

Disables throttle function.

Thrust/Drag Loads

(Propeller) These are somewhat uncertain due to the complexities of aerodynamic environments. The relative axial speed at the propeller (at any radial station) is the aircraft speed plus the amount the air in front of the blade is accelerated by the mechanics creating thrust. The latter may be approximated using first-order classical theory. Much empirical lift/drag data (from wind tunnel tests) exists to quantify lift/drag loads once relative velocity and angle of attack distributions are established.

Tip Stall

The outboard end of one wing (the tip) stops developing lift, causing the plane to roll suddenly in the direction of the stalled wing. This situation is not fun when you are only a few feet off the runway trying to land.

Torque

The force which tends to cause rotation.

Torsional Acceleration Loads

(Propeller) These are generally not known. Analytical estimating techniques used by Landing Products to quantify torsional acceleration loads suggest that they can become dominant when pre-ignition or detonation occurs. These observations are supported by test experience with very high-performance engines running at elevated temperatures. Such conditions cause high torsional loads (about the engine shaft) which create high bending stresses, adding to those from centrifugal force and lift/drag effects. These loads depend on unique conditions for specific engines, especially those "hopped up" for racing, where lean mixtures lead to high cylinder temperatures and pre-ignition/detonation.

Touch-And-Go

Landing and taking off without a pause. Often confused with a good bounce.

Trailing Edge (TE)

The aft-most edge of an airfoil or propeller.

Trainer Airplane

A model designed to be inherently stable and fly at low speeds, giving first-time modelers time to think and react as they learn to fly.

Trainer System

This effective method of training allows two transmitters to be connected by means of a trainer cord. The instructor can pass control over to the student's transmitter so that they can fly. If the student gets into trouble, the instructor can regain control instantly.

Transmitter

The hand-held part of the radio system that sends the signal to the receiver.

Tricycle Landing Gear

Refers to the landing gear configuration with a single steerable nose wheel mounted in front of the center of gravity and a set of main landing gear with two wheels positioned just behind the center of gravity. Tricycle landing gear is usually a little easier to use when learning.

Trim

The adjustment of a model's control surfaces to obtain a stable and balanced flight performance.

Vertical Fin

A fixed, vertical stabilizer that reduces the model's tendency to yaw about the vertical axis.

Washout

An intentional twist in the wing, causing the wing tips to have a lower angle of attack than the wing root. In other words, the trailing edge is higher than the leading edge at the wing tips. Washout helps prevent tip stalls.

Weathervane

An aircraft's natural tendency to turn into the wind.

Wheel Collar

A small, round retaining device used to keep wheels from sliding off an axle.

Wi-Fi

Wireless technology that allows devices to exchange data.

Wind Sock

A tubular flag-like device that shows the direction of wind movement. Wind speed may also be approximated by the angle at which the sock hangs. Used by pilots to aid with takeoff, landing, and flight patterns.

Wing Chord

The distance measured horizontally between the wing's LE and TE.