Hobbies And Interests
Aerodynamic Forces
There are four primary forces that act upon an aircraft in flight. These forces are lift, drag, gravity and thrust. Lift is the upward force created by the airfoil, or wing. Drag is the resistance of the aircraft being forced through the air. Gravity is the downward pull of the airplane toward the earth. Thrust is the forward force created by the airplane's engine.
Bernoulli's Principle
The lift generated by an airplane wing can be explained by Bernoulli's Principle. Daniel Bernoulli was a Swiss mathematician that explained that the pressure of a moving gas changes based on the speed of the gas. An airfoil's shape allows the air on top of the wing to move faster than the air flowing under the wing, decreasing the air pressure on top of the wing. This decrease in pressure creates a higher pressure value under the wing, creating lift.
Aircraft Control Surfaces
The control surfaces of the airplane are how the aircraft is controlled in flight. The four primary control surfaces are the ailerons, the rudder, the elevator and the flaps. The ailerons control the longitudinal axis, or the roll of the airplane. The rudder controls the yaw, or the right-left movement of the airplane. The elevators control the pitch of the aircraft, allowing control of the lateral axis of the aircraft. The flaps, when extended, increase the size of the wing's airfoil, thus increasing lift and allows flying at slower speeds for takeoff and landing.
Powerplant
Nearly all model aircraft have a powerplant that develops the thrust required to maintain flight, the exception being glider aircraft. The primary types of powerplants include electric motors, glow engines and ducted fan engines. Electric motors run off of a power source on the aircraft, such as a battery. Glow engines are an internal combustion engine, available in 2 or 4-stroke capacities. Model aircraft jets can also be powered by ducted fan engines. Larger model aircraft can use larger gasoline engines, such as those found on a chain saw.