The Private Pilot

1. The Private Pilot

2. Class 2 - Aerodynamics and Airplanes

3. Objective: To introduce the basic principles of aircraft performance, aerodynamics and flight controls.

4. Airfoil: Chord Line, Angle of Incidence, Angle of Attack

30. ANGLE OF ATTACK The acute angle between the chord line of the airfoil and the direction of the relative wind. ANGLE OF INCIDENCE The angle formed by the chord line of the wing and a line parallel to the longitudinal axis of the airplane.

32. The acute angle A is the angle ofA) attack.B) dihedral.C) incidence.

34. Lift Equation L = (1/2) ϱ v2 s CL • L = Lift, which must equal the airplane's weight in pounds • ϱ (“rho”is used) density of the air. This will change due to altitude.• • v = velocity of an aircraft expressed in feet per second• • s = the wing area of an aircraft in square feet• • CL = Coefficient of lift , which is determined by the type of airfoil and angle of attack

35. Critical Angle of Attack, Stall • The term "angle of attack'' is defined as the angle A) between the airplane's climb angle and the horizon. B) formed by the longitudinal axis of the airplane and the chord line of the wing. C) between the wing chord line and the relative wind.

36. What is the “Critical” Angle of Attack?

37. The angle of attack at which an airplane wing stalls will A) change with an increase in gross weight. B) remain the same regardless of gross weight. C) increase if the CG is moved forward.

38. The four forces acting on an airplane in flight are A) lift, weight, thrust, and drag. B) lift, weight, gravity, and thrust. C) lift, gravity, power, and friction.

39. What is the relationship of lift, drag, thrust, and weight when the airplane is in straight-and-level flight? A) Lift and weight equal thrust and drag. B) Lift equals weight and thrust equals drag. C) Lift, drag, and weight equal thrust.

40. Straight and Level

41. When are the four forces that act on an airplane in equilibrium? A) When the aircraft is at rest on the ground. B) When the aircraft is accelerating. C) During un-accelerated flight.

42. How will frost on the wings of an airplane affect takeoff performance? A) Frost will disrupt the smooth flow of air over the wing, adversely affecting its lifting capability. B) Frost will change the camber of the wing, increasing its lifting capability. C) Frost will cause the airplane to become airborne with a higher angle of attack, decreasing the stall speed.

43. Air Density, Air Pressure, Temperature and Humidity • High to Low, or Hot to Cold, Look out Below High Density Altitude = Low Air Density

45. DENSITY ALTITUDE— This altitude is pressure altitude corrected for variations from standard temperature. When conditions are standard, pressure altitude and density altitude are the same. If the temperature is above standard, the density altitude is higher than pressure altitude. If the temperature is below standard, the density altitude is lower than pressure altitude. This is an important altitude because it is directly related to the airplane’s performance.

46. Standard Atmospheric Conditions(Follow the Lines) At sea level, the standard atmosphere consists of a barometric pressure of 29.92 inches of mercury (in. Hg.) or 1013.2 millibars, and a temperature of 15°C (59°F).

47. What effect does high density altitude, as compared to low density altitude, have on propeller efficiency and why? A) Efficiency is reduced because the propeller exerts less force at high density altitudes than at low density altitudes. B) Efficiency is increased due to less friction on the propeller blades. C) Efficiency is reduced due to the increased force of the propeller in the thinner air.

48. Under which condition will pressure altitude be equal to true altitude? A) When indicated altitude is equal to the pressure altitude. B) When the atmospheric pressure is 29.92 inches Hg. C) When standard atmospheric conditions exist.

49. Under what condition is pressure altitude and density altitude the same value? A) When the altimeter has no installation error. B) At sea level, when the temperature is 0 °F. C) At standard temperature.

50. If a flight is made from an area of low pressure into an area of high pressure without the altimeter setting being adjusted, the altimeter will indicate A) higher than the actual altitude above sea level. B) the actual altitude above sea level. C) lower than the actual altitude above sea level.