Once you have your model and engine picked out and assembled, you need to start thinking about the radio control system. One thing I haven’t discussed yet is how the control surfaces( elevator, rudder, and ailerons) control the actions of you radio controlled model aircraft. Also, we will need to be able to control the engine speed with the throttle.
First, without getting into the complex details of aircraft design, let’s talk about how the control surfaces change the direction of the R/C model airplane in flight. The upper surface of the wing is actually longer than the bottom surface. When the air passes over the wing, the shape of the wing ( airfoil ) causes the air to move faster across the top surface than it does across the bottom surface. This causes greater upward pressure on the bottom of the wing creating lift which supports the weight of the airplane on the bottom surface of the wing.
The ailerons are the two long narrow control surfaces made into the trailing edge of the wing out near the the ends of the wing. On the smaller models, such as a trainer, they are connected together on one servo so that they move in opposite directions at the same time. As one aileron moves up the other one moves down. It is this action that causes the R/C model airplane to “bank” or turn by tipping one end of the wing downward while lifting the other end upward. When the ailerons are returned to the neutral position, the airplane returns to straight and level flight.
The tail section of the plane (often called the tail feathers) stabilizes the plane and controls the up and down movement as well as the left and right movement of the rear end. The movable part of the horizontal stabilizer is called the elevator and the moveable part of the vertical stabilizer is the rudder. Both the elevator and the rudder have one servo each in the smaller R/C model airplanes. If the plane has a nose wheel, it is controlled with the same servo that controls the rudder. Similar to the way the ailerons work, the rudder and nose wheel move at the same time to enable you to effective control the model when it is moving on the ground.
Before I explain how to install all the radio components, I will see if I can find some pictures that will help you understand how these things work to control the R/C model airplane both on the ground and in flight. Hopefully, I will have the pictures for the next post. See you next time and think about this: In R/C model flying, take-offs are optional, landing is mandatory!