Operation of Systems#
Airframe, wings & flight controls#
Primary Flight Controls#
Ailerons#
Wings have ailerons on the ends, the control surfaces for bank. When the yoke or stick is turned/pushed to the left, the left aileron raises up, decreasing the angle of attack, reducing lift on that side, and commencing a bank in that direction. The same is true of the right.
Rudder (Adverse Yaw)#
When one wing produces more lift (higher angle of attack, wing raises), it also creates more drag, causing the wing to slow down slightly. This results in the aircraft yawing towards the wing that increased lift, which is opposite the direction of bank. This effect is greater at lower speeds. Rudder application is required to counteract adverse yaw.
Elevator#
Pulling back on the controls raises the trailing edge of the elevator, creating a downward aerodynamic force that pushes down the tail and pitches the aircraft up about its center of gravity.
Secondary Flight Controls#
Flaps#
Closer to the wing root, doesn’t move differentially but together. Increases angle of attack, meaning more lift at slower airspeeds.
Spoilers#
Rise from the wing, reducing lift and increasing drag.
Trim#
Relieves pressure on the control stick. Usually are small hinged devices attached to the trailing edge of a control surface. Trim tabs are most common; placing it in full nose-down position places the trim tab in its full up position; airflow then pushes the rest of the elevator down, raising the tail and pitching the aircraft nose down.
Drag#
There are two basic types of drag:
Parasite drag: All the forces that work to slow an aircraft’s movement that are not associated with the production of lift.
Form drag: Drag generated by the aircraft due to its shape and airflow around it (e.g. engine cowlings, antennas, and the aerodynamic shape of other components).
Interference drag: Comes from the intersection of airstreams that creates eddy currents, turbulence, or restricts smooth airflow (e.g. the intersection of the wing and the fuselage at the wing root has significant interference drag).
Skin friction drag: The aerodynamic resistance due to the contact of moving air with the surface of an aircraft. Every surface, no matter how apparently smooth, has a rough, ragged surface when viewed under a microscope.
Induced drag: Induced drag is inherent whenever an airfoil is producing lift and, in fact, this type of drag is inseparable from the production of lift. Consequently, it is always present if lift is produced.
Landing gear & brakes#
Brakes are on a per-side basis, and are controlled via the rudder pedals. Pressing at the top of each pedal activates the brakes on the corresponding side of the aircraft.
During pre-flight inspection, check the brakes—they have a notch in them, so you can visually see when they’re getting low. Once they’re worn down to the depth of the notch, they need to be replaced.
Engine & propeller#
Induction, ignition & exhaust#
Oil & cooling#
The engine oil system performs many functions:
Lubrication of the engine’s moving parts
Cooling of the engine by reducing friction
Removing heat from the cylinders
Providing a seal between the cylinder walls and pistons
Carrying away contaminants
Fuel system & refueling#
When refueling, you should ground your aircraft with the electrical wire before pumping fuel. This reduces the risk of sparking and causing a fire.
Electrical system#
Pitot-static system & instruments#
Vacuum system & instruments#
Magnetic compass#
Magnetic deviation
Instruments in your airplane cause interference that affects your compass, and that interference is called deviation. Inside the compass, there are compensating magnets to counteract these fields of interference. A compass card is normally attached, showing what error correction to add for different headings, although the changes are normally just a few degrees.
Magnetic variation
Variation is the difference between true north and magnetic north. Isogonic lines are drawn on your sectional charts to show different lines of magnetic variation to help with planning your magnetic heading. “East is least, West is best.”
Acceleration error
Accelerate
North
Decelerate
South
Error is greatest on easterly/westerly headings.
Turning error
North
Opposite
South
Exaggerated
During a turn from a Northerly heading, the compass briefly indicates a turn in the opposite direction. As for aircraft turning from a Southerly heading, the compass indicates a turn in the correct direction, but at a faster rate than is actually being turned.