Ailerons, Rudder, and Elevator
Ailerons control roll about the airplane's longitudinal axis, which runs through the nose and tail. The ailerons are attached to the outboard trailing edge of each wing and move in the opposite direction from each other.
Rudder controls movement of the airplane about its vertical axis, which runs through the top and bottom of the airplane. This motion is referred to as yaw.
Elevator controls pitch about the lateral axis, which runs through the wingtips.
In small airplanes, the ailerons, rudder, and elevators are connected to the airplane's control wheels mechanically through cables and pulleys.
Wing Flaps
Flaps extend from the lower surface of the wings, increasing lift and drag to allow for lower landing speeds. At higher extension angles, flaps often greatly increase drag to allow for steeper approaches without increased airspeed. They are retracted for higher cruising speeds.
There are four common flap types:
1. Plain is the simplest flap design.
2. Split flaps increase lift and drag more than plain flaps.
3. Slotted flaps increase lift a great deal more than plain or split flaps by allowing high pressure air from below through the slots and over the flaps.
4. Fowler flaps are a type of slotted flaps which extend backwards and downward.
Trim
Most airplanes are equipped with elevator, aileron, and rudder trim. While aileron and rudder trim can generally be left alone for the most part, elevator trim must be adjusted every time the pilot changes the airplane's airspeed. If the airplane were flown out of trim, the pilot would have to hold constant pressure in the control wheel to maintain the desired aircraft orientation. The pilot uses the trim wheel to alleviate these control pressures.
The primary flight controls are the ailerons, rudder, and elevator.
The secondary flight controls include flaps and trim.