Principles of Flight

• If lift exceeds weight, the airplane will ascend.
• Air flowing over the top of a standard wing speeds up.
• There are four forces that act on an aircraft in flight: lift, weight, thrust, and drag.
• The area identified in the picture is the area of low pressure above the wing.
• Aircraft axes are imaginary lines running through the aircraft, used to define its orientation in three dimensions, there are three aircraft axes: longitudinal, lateral, and vertical.
• The two types of drag encountered by an aircraft are parasite drag and induced drag.
• Thrust opposes drag on a fixed-wing aircraft.
• Lateral stability is designed into a low wing aircraft by using dihedral, where the wings are angled upwards from the root.
• Factors leading to a stall of the airfoil are exceeding the critical angle of attack, and insufficient airspeed.
• If the angle between the chord line and relative wind becomes excessively high, airflow over the wing's top separates, causing a stall.
• The angle between the chord line and the relative wind approaching an airfoil is called the angle of attack.
• The angle between the chord line of the wing and a line at the trailing edge of the wing parallel to the longitudinal axis of the aircraft is called the angle of incidence.
• If one wing stalls more than the other, expect a roll or spin toward the stalled wing.
• "The chord" of an airfoil refers to the straight line connecting the leading and trailing edges of the wing.
• Thrust opposes drag on a fixed-wing aircraft.
• Roll (lateral) stability improves with wings designed with dihedral.
• Yaw (longitudinal) stability is maintained through the vertical stabilizer and rudder and the positioning of the wings.
• Pitch stability is maintained through the horizontal stabilizer and elevators.
• A straight line through the wings of an airplane passing through the center of gravity from wing tip to wing tip is the lateral axis.

Flight Controls

• Bank or Roll is motion along the longitudinal axis, controlled with ailerons.
• Yaw is motion about the vertical axis, controlled by the rudder.
• Pitch is motion about the lateral axis, controlled by the elevators.
• The combined flight control surfaces on the V-Tail of the aircraft in the picture are called ruddervators, they function as both rudders and elevators.
• Pulling the control wheel/stick aft (backwards) causes the plane to pitch up (nose up); the flight control is the elevator and the action raises the elevator.
• When the pilot moves the control wheel/stick to the left, the plane rolls to the left, the ailerons are the flight control and the pilot is raising the right aileron and lowering the left aileron.
• The small movable portions of the trailing edge of the control surface controlled from the cockpit are called trim tabs.
• The purpose of the slot on a wing is to allow high-pressure air from below the wing to flow over the top, increasing lift and delaying stall.
• Adverse Yaw caused by increased lift on a raised wing in a roll is countered using differential ailerons, coupled ailerons and rudder, or flaperons.
• Ailerons control Bank or Roll.
• A spoiler on a wing can reduce lift to descend, or act like a "speed brake".
• To relieve pilot input force and maintain a "Nose Up" attitude, the trailing edge of the trim tab on the elevator must be moved in the upwards direction.
• Fowler flaps increase lift and drag by extending both back and down.
• Rudder controls Yaw.
• Elevator controls Pitch.
• The illustrated flap is a slotted flap.
• The illustrated flap is a split flap.
• The illustrated flap is a fowler flap.
• The illustrated flap is a leading edge slat.
• The illustrated flap is a triple slotted flap.
• Two types of movable leading edge lift augmenting devices are slats and leading edge flaps.
• The name of the trailing edge tab that is used to move the flight control surface is a trim tab.
• The trailing edge device that counteracts the nose up or nose down tendency of the Stabilator Assembly is an anti-servo tab.
• The name of the device is a jackscrew.
• That device identified on the trailing edge of the rudder is a trim tab.
• This Auxiliary Device circled in the picture below is likely an air brake, used to slow the aircraft down by increasing drag.
• The Auxiliary Device circled are winglets, winglets reduce induced drag by disrupting wingtip vortices, improving efficiency.
• The auxiliary device is a vortex generator that energized the boundary layer.
• This auxiliary device is a de-ice boot to remove ice from the wing.
• The circled device is an angle of attack sensor.
• This device is a Yaw String, a yaw string is a device used to indicate the direction of the local airflow with respect to the aircraft, often seen on gliders.