# A B C D
E F G H I
J K L M N
O P Q R S
T U V W X
360, 540, etc.
Number describing degrees in an arc. A 360 represents one full turn through an
axis. A 360 turn, for example, is a flat turn where the aircraft does not roll
its wings but rather Just 'slides' through 360 degrees turning on rudder only.
For helis: A 540 stall turn, for example, describes a one and one half revolution
spin at the apex of a vertical stall, which results in the helicopter resuming
nose forward flight before recovery.
Term describing a type of flight pattern, which is characterized by the performance
of very specialized aerobatic maneuvers below the model's normal stall speed.
Examples include torque rolls, 'walk in the park', harriers, hangers, etc.
For helis: combining two or more maneuvers into one maneuver. Examples: rolling
circle, inverted backwards loop.
Slang abbreviation for flip flop flying. Similar to 3D, but without the finesse.
A return to top
ATL = adjustable Throttle Limiter
High-end feature which adjts to bring full servo potential within the limits
of bind-free servo travel. Ideal for throttle control, or for more effective
braking in gas racing.
ATV/EPA = adjustable Travel Volume/End Point Adjtment .
Allows separate adjtments of maximum servo travel to both sides of neutral.
Helps tailor outputs for different control styles.
Activating (Arming) Switch
An external switch that prevents the electric motor from accidentally turning
adjustable Function Rate (AFR)
Similar to ATV, AFR allows end point adjtment independent of Dual Rate or
adjustable Travel Volume (ATV)
End Point Adjtment, ATV you can independently preset the maximum travel of
a servo on either side of neutral.
Some airplanes, especially high-wing airplanes with flat-bottom airfoils, have
a tendency to yaw in the opposite direction of the bank. This is most common
when flying at low speeds with high angles. Adjting the ailerons can help
reduce the yaw.
Science of air in motion.
Towards the rear. used such as: "...with an aft center of gravity...."
Creating larger upward aileron travel than downward aileron travel to help minimize
the model "dragging" the drooped aileron which caes a model to yaw
with aileron input.
The Aileron Extension (also known as a servo extension) is a cable with connectors
on either end which goes between the receiver and a servo. This allows the servo
to be placed at a greater distance from the receiver than the cable that comes
on the servo will allow. It also permits easier removal of a wing when the servo
that controls the aileron is mounted in the wing and the receiver is in the
fuselage (which is Usually the case).
Hinged control surfaces located on the trailing edge of the wing, one on each
side, which provide control of the airplane about the roll axis. The control
direction is often confing to first time modelers. For a right roll or turn,
the right hand aileron is moved upward and the left hand aileron downward, and
vice versa for a left roll or turn.
Twin elevator servos plugged into separate channels used to control elevator
with the option to also have the 2 elevator servos act as ailerons in conjunction
with the primary ailerons.
Air Bleed Screw
Screw for adjting the amount of air allowed to bleed into the carburetor during
The shape of the wing when looking at its profile. Usually a raindrop type shape.
For helis: The rotor disk is the effective wing, and airfoil refers to the shape
of the blades.
AM, or Ampilitude Modulation, was the primary means of modulation in R/C until
recently. The control information is transmitted by varying the amplitude of
The Academy Of Model Aeronautics. The official national body for model aviation
in the United States. The official national body for model aviation in the United
States. AMA sanctions more than a thoand model competitions throughout the
country each year, and certifies official model flying records on a national
and international level.
An aircraft that can fly off of water or land. The wheels retract into the hull
or floats, depending upon the type of aircraft. An amphibian can land on water
and then extend the landing gear to allow it to pull up onto the shore. Many
seaplane bases had ramps to allow the airplanes to pull up onto dry land parking
Angle of attack
The angle that the wing penetrates the air. As the angle of attack increases
so does lift, up to a point (and drag).
The telescoping tube that transmits the signal.
The number of square inches (or feet) of the wing. It's the wingspan multiplied
by the wing's chord. The area of a tapered wing is the wingspan multiplied by
the average chord.
Almost Ready to Fly, a model airplane that can be put together with a minimal
amount of time.
This is borrowed from full sized helicopters, and is a rotor head which allows
the blades to flap, drag and feather.
The wingspan divided by the chord. Aspect ratio is important where a wing's
efficiency is concerned. A short aspect ratio (short wings) is better for maneuvering,
since it allows a high roll rate. Short wings are also stronger than long wings.
Gliders use high-aspect ratio wings (long, skinny wings) because they are more
efficient for soaring flight. Example: 10 ft. wingspan with a 1 ft. chord has
an aspect ratio of 10.
ATS, Revolution Mixing, or Anti Torque Compensation
This is " Automatic Tail System". This refers to the radio mixing
in a certain amount of tail rotor when the throttle / pitch is increased or
The ability of a rotary wing aircraft to land safely without engine power. This
maneuver uses the stored energy in the rotor blades to produce lift at the end
of decent, allowing the model to land safely.
The line around which a body rotates.
B return to top
BEC = Battery Eliminator Circuitry
Allows receiver to draw power from a main battery pack, eliminating the need
for (and weight of) a receiver battery.
Cover over the rear of the crankcase of an engine.
Ballast is extra weight added to a glider to help it penetrate better in windy
weather or to increase its speed. Ballast is Usually added in tubes in the inner
portion of the wings or in the fuselage at the center of gravity.
Servo's output shaft is supported with bearings for increased performance and
Connection using a ball, and a link which rotates on the ball. used to connect
the servo to a control surface or lever.
Term describing the amount of play between gears, or gear mesh. If too loose,
the gear can slip, or strip the teeth. Too tight, and excessive wear is caed.
Base Load Antenna
A rigid, short antenna mounted to the model. used to replace the longer receiver
To fully charge and discharge a battery to erase battery memory.
The device used to monitor the strength of the transmitter batteries
Bell and Hiller
Control system used in helicopters. Changes pitch of blades in relation to their
position via a swashplate. A flybar with paddles is used to gain responsiveness.
The two systems are linked with Control Levers.
What occurs when the friction at a joint is stronger than the linkage.
Boring holes in the sky
Having fun flying an R/C airplane, without any pre-determined flight pattern.
"Buddy" or Trainer Box
Two similar transmitters that are wired together with a "trainer cord."
This is most eful when learning to fly-it's the same as having dual controls.
The instructor can take control by using the "trainer switch" on his
Also known as crow. A mix which activates up flaperons and down inner-most flaps
for gliding speed control without spoilers or airbrakes.
C return to top
Abbreviation for cyanoacrylate. An instant type glue that is available in vario
viscosities (Thin, Medium, Thick, and Gel). These glues are ideal for the assembly
of wood airplanes and other materials. NOTE: Most CA glues will attack foam.
Cyclic-Collective-Pitch-Mixing. Type of swashplate mixing which requires a radio
with CCPM mixing functions. This uses three servos to control the cyclic, while
all three work together to raise and lower the swashplate for collective control.
CG = "Center of Gravity"
For modeling purposes, this is Usually considered-the point at which the airplane
balances fore to aft. This point is critical in regards to how the airplane
reacts in the air. A tail-heavy plane will be very snappy but generally very
unstable and sceptible to more frequent stalls. If the airplane is nose heavy,
it will tend to track better and be less sensitive to control inputs, but, will
generally drop its nose when the throttle is reduced to idle. This makes the
plane more difficult to land since it takes more effort to hold the nose up.
A nose heavy airplane will have to come in faster to land safely.
If you draw a line through the center of the airfoil that's exactly half-way
between the top and bottom surface, you get the mean airfoil line. Depending
upon the airfoil, it can be straight or curved. This curve is called the "camber"
of the airfoil. If it has a lot of curve, the airfoil is said to be "highly-cambered".
The horizontal surface forward of the wing used to control pitch. It's found
on very few aircraft. Also the word used to describe aircraft that have a main
wing and a horizontal control surface in the nose...also called, "tail
The maximum amount of energy a battery can store.
The part of the engine which controls the speed or throttle setting and lean/rich
mixture via setting of the needle valve.
An imaginary line drawn through the center of the aircraft from the nose through
Center of Gravity (CG)
Balancing point of an aircraft.
A very steep climbing turn where the airplane makes a 180o change of direction.
The frequency number used by the transmitter to send signals to the receiver.
If radios transmit on the same frequency, or channel, glitching will occur in
the active receiver on that channel. This is due to conflicting signals sent
by the two radios. Flying sites should have a frequency control system to ensure
that only one radio operates on any given channel at one time. This is Usually
a board with some type of marker for each channel. If the marker is not available,
someone else is using that channel. Do not use your radio unless you are sure
you are the only one on the frequency.
The number of functions your radio can control. Ex: an 8 channel radio has 8
available servo slots used for separate control surfaces or switches. These
channels can also be mixed on many radios, for such functions as collective,
which increases pitch when throttle is increased.
The plug receptacle of the switch harness into which the charger is plugged
to charge the airborne battery. An expanded scale voltmeter (ESV) can also be
plugged into it to check battery voltage between flights. It is advisable to
mount the charge jack in an accessible area of the fuselage so an ESV can be
used without removing the wing.
Device used to recharge batteries and Usually supplied with the radio if NiCad
batteries are included.
A hand-held stick used to start a model airplane engine.
The "depth" of the wing, its distance from leading edge to trailing
edge. One of the components used to determine wing area. May vary from root
The clevis connects the wire end of the phrod to the control horn of the control
surface. A small clip, the clevis has fine threads so that you can adJust the
length of the phrod.
Located in the fuel tank, a clunk is weighted and ensures that the intake line
has a steady supply of fuel.
Four Way Wrench
Combination wrench with sizes to fit glow plug, prop nut, etc.
Towards the front. used such as "...the forward edge of the rib...",
or as in "...with fore and aft movement...."
The frequency flag is a marker that is mounted on your transmitter to indicate
what frequency your system is operating on to alert other modelers so as not
to CAUSE interference.
The FCC has allowed the 72MHz (72.010 - 72.990) 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. The FCC has allowed band 75MHz (75.410 through
75.990) for ground model use only (robots, battlebots, cars, boats), 50MHz (50.800
- 50.980) is allocated only to Amateur HAM license holders for R/C use (and
only at 1W maximum power output.)
Rubber bulb used to transfer fuel to model tank
Fuel Overflow Line (Vent)
This line pressures the fuel tank and provides an even fuel flow to the engine.
It also functions as an overflow line when the fuel tank is full.
Fuel Pickup Line
This line connects the fuel tank to the carburetor, Usually with a clunk on
the tank end to keep the fuel flowing while the aircraft is in flight. fuselage.
The main body of an airplane.
The body of an airplane.
G return to top
Gyro sensitivity. When too low, the tail will not hold position well. When too
high, the surface being dampened by the gyro will tend to wag, or hunt for center.
Gimbal (or Stick)
The device that allows the er to input desired control movements into the
The glide ratio is defined as the distance travelled in a horizontal direction
compared with the vertical distance dropped on a normal glide. A 10 to 1 glide
ratio means that the aircraft would loose one foot of altitude for every ten
feet of distance traveled.
Momentary radio problem that never happens unless you are over trees or a swamp.
The heat source for igniting the fuel/air mixture in the engine. When starting
the engine a battery is used to heat the filament. After the engine is running,
the battery can be removed. The wire filament inside the plug is kept hot by
the "explosions" in the engine's cylinder. See next heading and "Idle
A very smooth, gentle landing without a hint of a bounce.
A gyro is an electro-mechanical, or electronic device which aids in the control
of an R/C model. The gyro senses motion in one axis, and directs the servo to
counter that motion. The sensor, which can be a mechanical gyroscope, or an
electronic piezo crystal, detects unwanted movement. The gyro then instructs
the servo to counter for that motion. At all times, the radio commands will
override the gyro command. The level of control the gyro had is adjusted by
the GAIN setting.
Mechanical Gyro: uses a mechanical gyroscope (similar to the child's toy) to
Piezo Gyro: uses a piezo crystal to sense movement.
Non-Heading-hold vs. heading hold: A standard (nonHH) gyro senses movement and
makes an effort to counter that movement as long as it feels it. Therefore,
it is NOT going to return the model to the exact heading prior to the movement.
Heading Hold (or AVCS) gyros will lock the model into one position, and accurately
correct for movement by sensing rate of change and returning at that same rate.
SMM technology: utilizes a microchip to sense movement and provide all readings.
Experiences minimal effect from temperature change, commonly known as 'temperature
drift' which affects piezo and some mechanical gyros.
H return to top
The device for carrying the transmitter
A device consisting of wires, switches, and a fe that connects a motor to
The component which forms the end of the compression chamber of the engine
This describes a type of Gyro which senses rotation, and maintains direction.
This is accomplished by sensing the rate of motion, and the time of motion,
then compensating for the distance. While this sounds complicated, the effect
is that if you have the model dialed in, and point the nose north, with a heading
hold gyro on the yaw axis the model will continue to face north until you command
it to yaw. See also Heading Lock. This is not recommended for aircraft use while
in flight due to the requirement to use YAW (rudder) command to turn the model.
Often used for ground use only for perfect take off and landing runs.
Slang term for Heading Hold Gyro.
High Efficiency Clock. High motor pulse frequency, giving very fine control
of motor speed, and saving current in the part-load range. Produces longer running
times and reduces the thermal load on the motor.
A remote control radio system designed specifically for use with helicopter
models. The helicopter radio differs from an aircraft radio in a few ways. First,
the heli radio needs mixing functions specific to helicopters, and Usually a
minimum of five channels. Collective mixing for collective pitch helicopters
is a necessity. Second is the throttle stick, which is ratcheted in airplane
transmitters, will not have the clicking feel on the heli version. This is due
to the precise control needed on the heli collective stick to achieve and stain
a controlled hover. The specific radio requirements will vary from er to er,
and the parameters used will vary from helicopter to helicopter. Note that many
radios produced have both airplane and helicopter programming in a single radio.
This term describes an airplane that has its wings mounted on the top of the
The hinges are the moving blades on the control surface that allow you to control
the airplane's movement. All hinges mt be glued properly and securely to prevent
the airplane from crashing.
Hit (or to be hit)
Sudden radio interference which caes your model to fly in an erratic manner.
Most often caused by someone turning on a radio that is on your frequency, but
can be caused by other radio sources miles away.
The horizontal tail surface at the back of the fuselage which provides aerodynamic
pitch stability to the airplane.
This is the amount of pitch you will need to hover the helicopter. On average
this is about 5 degrees. Most helicopter radio's will have a knob on the transmitter
to vary the amount of pitch at the present hovering stick position.
This is the amount of throttle you will need to hover the helicopter. On average
this is about 50% throttle. Most helicopter radio's will have a knob on the
transmitter to vary the amout of throttle at the present hovering stick position.
I return to top
J return to top
K return to top
L return to top
This is a setting on the transmitter which limits the throttle minimum. Particularly
useful for FFF and 3D stunt flying.
A maneuver originally used to reverse direction in combat. The airplane noses
up and over onto its back. It then rolls upright and continues in the direction
opposite to the original direction. It was invented by the World War I German
pilot Max Immelmann, whose airplane could perform the maneuver, and others couldn't.
It got him out of a lot of trouble in combat until the Allied aircraft designs
caught-up and allowed their planes to perform the maneuver, too.
An air inlet on an aircraft. You can have a carburetor intake, cooling intake,
air conditioning intake (on full-size aircraft), and so on. Named becae it
"takes in" air, and becae "intake" is a better-sounding
word than "takes in".
This is when the helicopter is inverted and the funtions of the Pitch, Elevator,
Rudder can be reversed by the use of the "Inver" switch or the pilot
can do it him or her self at the sticks. This is refered to as "Switchless"
Lnverted Flight Control
Activates inverted flight programming for helis, which reverses the direction
of the rudder, pitch and elevator servos, and sets up inverted flight pitch
high-side and low-side. Inverted programming is used to allow the radio inputs
to be identical to upright flight while the model is inverted. Note: this approach
to hovering is seldom ed. Instead, idle-ups are used and the modeler learns
to understand and respond to the controls' reversal in inverted flight.
Lift divided by drag expressed as a ratio. Essentially the same as a glide ratio.
Think of L/D as a glide slope, then, for a given amount of distance the sailplane
moves forward, it drops a certain amount.
The assemblies that include the wheels and the wheel struts. The word "gear"
is used in the sense of "equipment", as opposed to the "toothed
wheel" meaning of "gear". The British call the landing gear the
The left-right or side-to-side balance of an airplane. An airplane that is laterally
balanced will track better through loops and other maneuvers.
Leading Edge (LE)
The very front edge of the wing or stabilizer. This is the edge that hits the
The stroke of an engine refers to the distance the piston travels from top to
bottom. In a Long Stroke engine this distance is a bit longer than on the standard
engine making the engine a bit stronger in torque and operation lower RPM. Quite
often an engine is "Long Stroke" if the stroke distance is greater
than the diameter of the piston.
A vertical circle in the air. The plane noses up, keeps rotating until it's
on its back, and then comes down and around to describe a vertical circle in
M return to top
MHz = Megahertz
The unit of radio frequency. 75 MHz are surface frequencies; 72 MHz are air
frequencies; 27 MHz and 50 MHz can be used for either ground or air applications.
Note: use of the 50 MHz (ham radio) band requires an FCC license.
Speed in Miles Per Hour. Like RPM, MPH is both singular and plural.
mAh (Milliamp Hour)
A measure of a battery's capacity. The larger the number of milliamp's the longer
the battery cell will last.
Also Main Landing Gear. The large, heavy-duty landing gear struts and wheels
that support most of the weight of the airplane. They are Usually under the
wing or under the fuselage near the center of the aircraft. Any other landing
gear struts and wheels are noticeably smaller.
Main Landing Gear
The wheel and gear assembly the airplane uses to land. It is attached to the
bottom of the fuselage.
Drive gears within a servo which are made of one or multiple metal types. Metal
gears tend to wear more rapidly than nylon gears when in the same installation,
and so require more frequent service to maintain optimum accuracy; however,
metal gears are more durable in the case of severe vibration, flutter, or physical
The speed at which a sailplane loses altitude most slowly. Usually expressed
in feet per minute.
Allows a single input to control the operation of two or more servos. Simplifies
routine flying and allows more involved maneuvers-great for intermediate-advanced
fliers. For example, Flap-to-elevator mixing: Most models will change pitch
upon deploying flaps (some will climb; others dive). After test flying the model
and determining the direction and amount of elevator throw required to correct
for this change, a pilot may set a flap-to-elevator mix to compensate. Once
the mix is operating properly, when the modeler gives flap control, the radio
automatically also gives the proportional amount of elevator throw, keeping
the model flat and straight.
A specialized lever which has three or more pivots. The length between pivots
will determine the proportion of the mix between two or more linkages.
The control stick configuration with the rudder and elevator being controlled
by the left stick while the right stick controls the throttle and ailerons.
The control stick configuration with the ailerons and elevator being controlled
by the right stick while the left stick controls the rudder and throttle.
The control stick configuration with the rudder and elevator being controlled
by the right stick while the left stick controls the ailerons and throttle.
A removable/replacable plug in unit used in most complex computer radios, containing
all frequency control equipment, including the crystal and all tuned components.
Changing channels or bands on a modular radio requires only changing module.
Changing crystals WITHIN a module to change the channel of the module itself
is against FCC regulation and is not recommended. To use your transmitter on
a different channel you simply purchase another module on that other channel
and the radio is now fully properly tuned and safe and easy to use on that other
channel as well.
Futaba module models include TP, TK, TJ, TL, and TK-FSS. For information on
which module to e, see 9Z/8U modules, TF modules and aftermarket modules.
The section of the crankcase used to mount the engine to the airplane
This device muffles engine noise and increases the back pressure from the engine's
exhat stack, which can improve the airplane's performance at low speeds. Mufflers
are Usually required by R/C Clubs.
N return to top
Span, also "Wingspan"
The widest straight-line distance between the two wingtips.
Large panels that fold out of the aircraft structure to provide a lot of extra
drag to the air. They are not part of the wing structure, but are Usually mounted
on the fuselage. Military jets most often have speed brakes, which fold out
of the fuselage. Some airliners use spoilers as speed brakes when at altitude.
An electronic device that functions as a throttle for an electric motor. A speed
control controls the speed or rpm of an electric motor.
The middle control surface on a 6-trailing-edge-surface glider or the inboard
control surface on a 4-surface glider.
A maneuver where at least one wing is stalled and the two wings are operating
at very different angles of attack. This caes the airplane to rotate around
its middle while it descends at a high rate of speed. When it's done on purpose,
it is a precision maneuver, with the pilot trying to get the airplane to rotate
an exact number of turns from entry to exit. When it's done accidentally, it
can easily result in a crash. Many models crash when the pilot enters an accidental
spin too close to the ground. This is caused by improper speed control during
the landing approach.
The bullet-shaped fairing on the nose of the airplane around the propeller.
This smooths the airflow around the propeller hub and also makes the airplane
looks much better.
Basically a reverse Immelmann. The airplane rolls onto its back, and then the
nose comes down to finish a 1/2-loop. The direction of flight is changed 180o.
Control surfaces on the wing that destroy lift. They "spoil" it. They
are used on sailplanes because they can steepen the very flat glide of the aircraft,
which makes landings much easier. On full-size aircraft, spoilers are also used
to kill lift on landing to make sure the airplane is firmly on the ground. They
also add a lot of drag to help with aerodynamic braking.
Stabilizer+elevator, also called full-flying tail. Stabilizer incidence controlled
by pilot in lieu of an elevator.
The Stabilizer is the fixed horizontal surface at the rear of an aircraft. It
provides pitch stability for the aircraft.
What happens when the angle of attack is too great to generate lift regardless
of airspeed. (Every airfoil has an angle of attack at which it generates maximum
lift-the airfoil will stall beyond this angle).
Basically this is a supporting member. A wing strut supports the wing, and goes
from the fuselage to the wing. Cabane struts are on biplanes, and support the
upper wing over the fuselage. A landing gear strut is the portion that holds
the wheel assembly to the airplane, and away from the wing or fuselage.
This is a trim function on many computer radios, allowing trim function during
set-up, and still allowing the full trim function in flight.
This switch is commonly located on the fuselage and governs the on/off mechanism
for the flight pace. Tachometer. A device the measures the engine's RPM (rotations
per minute) by counting light impulses that pass through the spinning propeller.
A Symmetrical Wing airfoil is curved on the bottom to the same degree as it
is on the top. If a line was drawn from the center of the leading edge to the
center of the trailing edge the upper and lower halves of the airfoil would
be symmetrical. This is ideal for aerobatic aircraft and most lift is created
by the angle of incidence of the wing to the flight path.
T return to top
An optical sensor designed specifically to count light impulses through a turning
propeller and read out the engine RPM.
The nickname of an airplane that sits on its tail with the two main wheels in
front and a tailwheel in the rear.
Stabilator with collective and differential actuation.
On old World War I type aircraft, or pioneer-type aircraft, there was no tailwheel.
A wooden skid was used to support the tail of the airplane. While this helps
slow the airplane during landing, it is eless as an aid to steering on the
ground. The real aircraft with tailskids had to be maneuvered on the ground
by ground crews, who put the tail on a small cart and towed the airplane where
they wanted it. For small distances, the tail was picked-up by hand and the
airplane phed into position by the ground crew.
The small wheel at the tail of the airplane. This is found on the type of airplane
that have the two large wheels in the front, and the small one in the rear.
The airplane sits on its tail.
Rising body of hot air that can take a sailplane to a great height.
A liquid that solidifies; used to prevent screws from loosening due to vibration.
The control that allows the pilot to change the speed of the engine. In a car,
the "gas pedal" is actUsually the throttle control for the car.
The programming function of the radio which allows throttle operation to be
adjusted to meet the modeler's specific needs at vario points along the throttle
movement. Particularly useful with 2-stroke engines in providing linear throttle
response at the vario points of throttle application.
For helis: Aids in setting the hover point, and end points of the throttle in
the collective mix.
A radio function which locks the throttle at a fixed point while a switch is
activated. This function is used to hold the throttle in an idle. useful when
starting, as well as for auto rotations.
Throttle Stop Screw
Screw for setting the lower limit of the throttle movement
The forward force provided by the airplane's engine. This is the force that
drives the airplane forward.
The force which tends to CAUSE rotation.
Inserted into ailerons, these rigid wire rods run along the wings' trailing
edge, then bend downward and connect to the phrods.
The tow-hook is a small metal hook mounted on the bottom of the glider fuselage
at approximately the center of gravity and to which the hi-start or winch is
Trailing Edge (TE)
The rearmost edge of the wing or stabilizer.
A model designed to be inherently stable and fly at low speeds, to give first-time
modelers time to think and react as they learn to fly.
Allows trainer to link radios with a student via a cord, and to instantly take
control of student's craft in-flight. The 8U system has special training features
The hand-held radio controller. This is the unit that sends out the commands
that you input.
The landing gear arrangement where the airplane has main gear and a nose gear.
Slides used to adJust control surfaces during flight.
Abbreviation for transmitter.
U return to top
This means that the lower surface of the wing has a hollow curve when observed
from front to back. A thin wing with a high camber will be undercambered.
V return to top
A V-Tail is a special tail surface configuration where the horizontal stabilizers
and elevators are mounted at an angle between 30 and 45 degrees in a V-shape
and the vertical fin is eliminated entirely. The stabilizers provide stability
in both pitch and yaw while the moveable surfaces provide directional control
in both pitch and yaw.
used when there is a V-Tail on the aircraft rather than the conventional elevator
and rudder. Each control surface of the V is connected to a separate servo.
Operating the elevator control stick will move both surfaces up for back stick
or both surfaces down for forward stick. Moving the rudder control stick left
will move the left surface of the V down and the right surface up. Moving the
rudder control stick to the right will move the left surface of the V up and
the right surface down.
Variable Trace Rate (VTR)
This radio function is similar to exponential except it es two linear responses
to determine the servo sensitivity on the first and second half of the control
A small vertical surface on the bottom of the aft fuselage. Usually a long,
slim triangle that is narrow at the front, and widens toward the rear. It Usually
ends at the rudder hinge line.
The vertical surface of the tail gives the airplane stability while in flight.
The non-moving surface that is perpendicular to the horizontal stabilizer and
provides yaw stability. This is the surface to which the rudder attaches.
W return to top
An intentional twist in the wing, caing 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, and helps
the "PT" family of trainers recover, hands-off, from unwanted spiral
The round retaining piece that anchors wheels in place on the axle.
The large fairings used to streamline the wheels of an aircraft that has non-retracting
or "fixed" landing gear (so-called because it's "fixed"
Because wings provide the primary lift force on an airplane, adjtments to
the wings affect the airplane's movements while in flight.
The Wing Area is the total surface area of the wing of the aircraft, Usually
calculated by the wingspan times 7the wing chord, although more complex calculations
are used on unconventional wing plans.
The Wing Chord of an aircraft is distance from the front or "leading edge"
of a wing to the back or "trailing edge".
Wing loading is the weight of the aircraft divided by the wing area. It is designated
ounces per square foot.
Wing Seating Tape
Wing seating tape is mounted on the fuselage wing saddle where the removeable
wing fits and isolates the wing from vibration as well as to form a seal to
keep exhat gases from entering the structure.
The maximum distance from wingtip to wingtip.
The very outer end of a wing.
A small vertical surface at the tips of the wings. They help direct the turbulent
airflow that all wings have at the tips. They make the wings more efficient.
X return to top
Y return to top
The nose-left and nose-right movement of the airplane. This is controlled by
The airplane axis controlled by the rudder. Yaw is illtrated by hanging the
airplane level by a wire located at the center of gravity. Left or right movement
of the nose is the Yaw movement.
Z return to top
The wire ends of phrods have Z-shaped bends, which attach to the servo.
used for crimping wire ends into Z bends.