The external parts
Fuselage
The fuselage is the basic structure to which the wings and empennage are attached.
Wings
Almost all modern airplanes have a single wing, mounted either above or below the fuselage. Most high wing airplanes have supporting struts. Fuel tanks are commonly contained within the wings.
Empennage
The horizontal stabiliser, the rudder, the vertical fin, the elevator, or any combination of these is called the empennage. These surfaces allow the pilot to change the airplane’s attitude in relation to the horizon by moving the nose up and down (using the yoke or control stick) or left and right (using the rudder pedals).
There may be a fixed horizontal stabiliser with a movable elevator, or the whole horizontal assembly may be movable (called a stabilator).
Flying surfaces & flight controls
Movement of the yoke or stick is transmitted by pushrods or cables to the ailerons and elevator, while the foot pedals act on the rudder.
Ailerons
Ailerons are the movable control surfaces at the outer trailing edges of the wings. These are used to bank the airplane by moving the yoke or stick in the direction of desired bank. When no control force is exerted, the ailerons are held flush with the wing surface by the airstream.
primary effect: roll
secondary effect: yaw
Elevator
The elevator is the horizontal movable control surface at the tail. The elevator is used to change the pitch of the airplane up or down by moving the yoke or stick forward or back.
primary effect: pitch
secondary effect: airspeed
Rudder
The rudder is the movable control surface at the trailing edge of the vertical stablisier. The rudder is used to change the yaw of the airplane, rotating it around the vertical axis. Unlike a boat, the rudder is not used to steer the airplane; it is used to overcome adverse yaw induced by turning.
primary effect: yaw
secondary effect: roll
Flaps
Flaps are a high-lift device hinged to extend downward on the trailing edges of the wings near the fuselage. Flaps increase the surface area of the wing resulting in an increase in both lift and drag and a reduction of stall speed. These are normally used to steepen the glide angle without increasing airspeed, for example when approaching to land.
Flaps can also be used to assist takeoff from a short or soft runway.
Trim tabs
The elevator will have a trim tab. This tab is adjusted so the pilot can maintain a desired control position without exerting constant pressure. More modern aircraft may have trim tabs on all 3 axes.
Trim tabs are used only to relieve pressure on the flight controls, and are not to be used by themselves to change the airplane’s attitude. When the airspeed and altitude are at the desired values, any remaining control pressures should be trimmed off. When the airplane is stabilised in level flight, it is said to be ‘trimmed’.
Other parts
Landing gear
Most small aircraft have 3 wheels in a ‘tricycle’ layout. The 2 main wheels are designed to withstand landing loads and support the airplane on the ground. The third, smaller wheel at the front is for steering on the ground and is not designed to absorb landing loads. Many planes use the rudder pedals for steering, while some use the brakes to cause a turn. There will normally be disc brakes on the 2 main wheels.
Propeller
Propellers usually have 2 or 3 blades, but can have more. They are usually fixed pitch – this means the angle of the blade does not change. Some planes have variable pitch propellers which can change the angle of the pitch electrically during flight.
Planes with the propeller on the front are called ‘tractor’ type.
Planes with the propeller at the rear are called ‘pusher’ type.
Engine
Most small aircraft use the 100hp Rotax 912 engine. It is a twin-carburetted, horizontally-opposed 4-cylinder, 4-stroke engine with a reduction gearbox to the propeller. It has liquid-cooled cylinder heads and air-cooled cylinders.
Lights
Small aircraft have a number of lights.
The landing light is on the front of the aircraft and is designed to be visible to people/planes on the ground as a warning when you are landing.
The position lights (nav lights) are on the wingtips and tail; red on the left, green on the right and white on the tail.
Strobes (anti-collision) can be red or white or both, and and are used to make the aircraft more noticeable.