New To R/C - Aircraft Terminology

Aircraft Terminology
Here are some terms that may baffle you as an newcomer but in time will become very familiar:

The fuselage is the body part of the aircraft which holds the passengers, cargo, or in the case of an R/C aircraft, the radio system.

The wing of the aircraft is the large horizontal surface which produces the lift and allows the craft to fly. Wing placement may be on the upper part of the fuselage known as a high wing plane. This is more common on trainer type aircraft as a high wing model is more stable due to the pendulum effect of the fuselage. A wing mounted on the bottom of the fuselage is referred to as a low-wing aircraft and is more suitable for aerobatic type aircraft as stability is more neutral and manoeuvres such as rolls and loops are more easily done.

Wing Span
The Wingspan of an aircraft is the length of the wing as measured from wing tip to wing tip.

Wing Chord
The Wing Chord of an aircraft is distance from the front or "leading edge" of a wing to the back or "trailing edge".

Wing Tip
The very outer end of a wing.

Wing Area
The Wing Area is the total surface area of the wing of the aircraft, usually calculated by the wing span times the wing chord, although more complex calculations are used on unconventional wing plans.

The Airfoil is the shape of the cross section of the wing. The front of the airfoil is the leading edge and is usually a rounded section. The back of the airfoil is the trailing edge and usually tapers to nearly a point. The distance between the two is the wing chord. The top surface of the airfoil is usually always curved to allow smooth airflow and produce lift.

Flat Bottom
A Flat Bottom Wing is when the lower surface of the wing is primarily flat between the leading and trailing edges. This type of wing has high lift and is common on trainer type aircraft.

A Fully-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.

A Semi- symmetrical Wing airfoil has a curved bottom section but to a lesser degree than a symmetrical section. It is a compromise between the flat bottom and the symmetrical wing. This is a very popular airfoil on sport type aircraft.

An Under-camber airfoil has the lower surface of the wing curved inwardly almost parallel to the upper surface. This type of airfoil produces a great deal of lift but is not common in R/C models.

The Dihedral of a wing is the V-shape the wing makes or the angle between the wing and the horizontal. Usually the greater the dihedral angle the more stable the aircraft will be (to a point!) and is common in trainer type aircraft. A flat wing with little or no dihedral is less stable and more suited to aerobatics.

The pitch refers to the angle of the aircraft in the up or down direction.

The roll refers to the rotation of the aircraft around it's centerline (one wing up and one wing down).

The yaw refers to the angle of the aircraft in the side to side direction.

Control Surface
A moveable surface, attached to the airframe of an aircraft, which controls the direction of the aircraft.

An Aileron is a moveable surface on trailing edge of the wing which provides directional control of the roll of the aircraft. A Strip Aileron is an aileron that is narrow and usually takes up the entire, or most of the trailing edge of a wing. A Barn-door Aileron is wider and takes up a smaller portion of the trailing edge towards the wing tip.

The Elevator is the horizontal moveable control surface at the tail of the model connected to the stabilizer. It controls direction in pitch.

The Stabiliser is the fixed horizontal surface at the rear of an aircraft. It provides pitch stability for the aircraft.Fin
The Fin, also known as the "vertical stabiliser", is the fixed vertical surface at the rear of an aircraft. It provides yaw stability for the aircraft.

The Rudder is the moveable control surface at the tail of the model connected to the fin. It controls direction in yaw.

A V-Tail is a special tail surface configuration where the horizontal stabilisers and elevators are mounted at an angle between 30 and 45 degrees in a V-shape and the vertical fin is removed entirely. The stabilisers provide stability in both pitch and yaw while the moveable surfaces provide directional control in both pitch and yaw.

Flaps are a control surface found on some aircraft, usually located on the inboard trailing edge of each wing. Flaps may be lowered to increase the lift of the aircraft by simulating an under-camber airfoil.

A Spoiler or Airbrake is a control surface more commonly found on gliders and jet aircraft which is used to slow down the aircraft and to reduce lift. They are rarely found on conventional aircraft. They may be mounted on either the top or bottom of the center portion of the wings.

Center of Gravity. CG.
The Center of Gravity is the position in the aircraft where if a point was placed, the plane would balance. The "C of G" should usually found along the centerline of the aircraft at a distance approximately 1/3 of the way behind the leading edge of the wing.

Landing Gear
The landing gear of the aircraft refers to the support between the wheels and the wing or fuselage. It is usually is formed from metal, wire or a nylon/fiberglass combination.

Another name for landing gear.

Tricycle Undercarriage
Tricycle refers to the landing gear configuration where there is a single steerable nosewheel 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. This type of undercarriage is usually a little easier to use when first learning.

Tail Dragger
This refers to the undercarriage 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.