Private Pilot Exam - ASA Chapter 1: Basic Aerodynamics Practice Questions With 100% Verified Correct Answers.

Airfoil - correct answer is a structure or body which produces a useful reaction to air movement. Airplane wings, helicopter rotor blades and propellers are airfoils. Chord Line - correct answer is an imaginary straight line from the leading edge to the trailing edge of an airfoil. Changing the shape of an airfoil will change the chord line relative wind - correct answer is the wind relative to the airfoil. it is created by the movement of air past an airfoil, by the motion of an airfoil through the air, or by a combination of the two. angle of attack - correct answer is the angle between the chord line of the airfoil and the relative wind. By manipulating the aircraft controls, the pilot can vary the angle of attack angle of incidence - correct answer is the angle at which a wing is attached to the aircraft fuselage. The airplane pilot has not control of the angle of incidence lateral axis - correct answer is an imaginary line from wingtip to wingtip for an airplane pitch - correct answer is the rotation around the lateral axis, and is controlled by the airplane's elevators, or by pushing the yoke forward or pulling it backwards longitudinal control or longitudinal stability - correct answer is the rotation along the lateral axis, or pitch longitudinal axis - correct answer is an imaginary line from the nose to the tail of the airplane. Roll - correct answer is the rotation around the longitudinal axis and is controlled by use of the ailerons lateral control or lateral stability - correct answer is the rotation along the longitudinal axis Vertical axis - correct answer is an imaginary line extending vertically through the intersection of the lateral and longitudinal axes Yaw - correct answer is the rotation around the vertical axis and is controlled by the rudder directional control or directional stability - correct answer is the rotation along the vertical axis center of gravity - correct answer is the imaginary point where all of the weight of the airplane is concentrated, which would be the point where the airplane would balance if it was held at that point, and is also where all three of the axes intersect The four aerodynamic forces - correct answer Weight, Lift, Drag, and Thrust Lift - correct answer is the result of a pressure difference between the top and the bottom of the wing, where air over the top camber of the wing moves faster, and the air on the bottom camber moves slower Bernoulli's Principle - correct answer is that as the velocity of a fluid (gas or liquid) increases, its pressure decreases Weight - correct answer is the force with which gravity attracts all bodies vertically toward the center of the earth Thrust - correct answer is the forward force which is produced by the propeller acting as an airfoil to displace a large mass of air to the rear. Drag - correct answer is a rearward-acting force which resists the forward movement of an airplane through the air - with the two types of drag being parasite and induced drag Parasite drag - correct answer is the resistance of the air produced by any part of an airplane that does not produce lift (examples such as antennae and landing gear would be such drag). Parasite drag will increase as airspeed increases induced drag - correct answer is a by-product of lift. In other words, drag is induced as the wing develops lift. The high pressure air beneath the wing, which is trying to flow around and over the wingtips into the area of low pressure, causes a vortex behind the wingtip. This vortex induces a span wise flow and creates vortices all along the trailing edge of the wing. Lift = Weight, and Thrust = Drag - correct answer is when all of the four aerodynamic forces (lift, thrust, wight, and drag) are in equilibrium, which results in straight and level flight Stability - correct answer is the inherent ability of an airplane to return or not return to its original flight condition after being disturbed by an outside force such as rough air Positive Static Stability - correct answer is the initial tendency of an aircraft to return or not return to its original position Positive Dynamic Stability - correct answer is the tendency of an oscillating airplane (with positive static stability) to return to its original position relative to time Effects of Forward CG - correct answer 1. Increased longitudinal stability 2. Lower cruise speed. The wing flies at a higher angle of attack to create more lift to counter the added downward forces produced by the tail, therefore the wing also produces more induced drag 3. Higher stall speed. The wing flies at a higher angle of attack to create more lift to counter the added downward forces produced by the tail, therefore the wing also produces more induced drag Effects of Aft CG - correct answer 1. Decreased longitudinal stability 2. Higher cruise speed (for just the opposite reason listed above). 3. Lower stall speed