Chapter 1: Airplanes and Aerodynamics
A. FLAPS AND RUDDER
1) One of the main functions of flaps during the approach and landing is to increase
wing lift, which allows an increase in the angle of descent without increasing airspeed.
2) The rudder is used to control the yaw about the airplane's vertical axis.
B. AERODYNAMIC FORCES
1) The four aerodynamic forces acting on an airplane during flight are :
i. Lift – the upward-acting force
ii. Weight – the downward-acting force
iii. Thrust – the forward-acting force
iv. Drag – the rearward-acting force
2) These forces are at equilibrium when the airplane is in unaccelerated flight:
i. Lift = Weight
ii. Thrust = Drag
C. ANGLE OF ATTACK
1) The angle of attack is the angle between the wing chord line and the direction of
the relative wind.
i. The wing chord line is an imaginary straight line from the leading edge to
the trailing edge of the wing.
ii. The relative wind is the direction of airflow relative to the wing when the
wing is moving through the air.
2) The angle of attack at which a wing stalls remains constant regardless of weight,
airplane loading, etc.
D. STALLS AND SPINS
1) An airplane can be stalled at any airspeed in any flight attitude. A stall results
whenever the critical angle of attack is exceeded.
2) An airplane in a given configuration will stall at the same indicated airspeed
regardless of altitude because the airspeed indicator is directly related to air density.
3) An airplane spins when one wing is less stalled than the other wing.
i. To enter a spin, an airplane must always be stalled first.
E. FROST
1) Frost forms when the temperature of the collecting surface is at or below the
dewpoint of the adjacent air, and the dewpoint is below freezing.
i. The water vapor sublimates directly as ice crystals on the wing surface.
2) Frost on wings disrupts the smooth airflow over the airfoil by causing early airflow
separation from the wing. This
i. Decreases lift, and
ii. Causes friction and increases drag.
3) Frost may make it difficult or impossible for an airplane to take off.
A. FLAPS AND RUDDER
1) One of the main functions of flaps during the approach and landing is to increase
wing lift, which allows an increase in the angle of descent without increasing airspeed.
2) The rudder is used to control the yaw about the airplane's vertical axis.
B. AERODYNAMIC FORCES
1) The four aerodynamic forces acting on an airplane during flight are :
i. Lift – the upward-acting force
ii. Weight – the downward-acting force
iii. Thrust – the forward-acting force
iv. Drag – the rearward-acting force
2) These forces are at equilibrium when the airplane is in unaccelerated flight:
i. Lift = Weight
ii. Thrust = Drag
C. ANGLE OF ATTACK
1) The angle of attack is the angle between the wing chord line and the direction of
the relative wind.
i. The wing chord line is an imaginary straight line from the leading edge to
the trailing edge of the wing.
ii. The relative wind is the direction of airflow relative to the wing when the
wing is moving through the air.
2) The angle of attack at which a wing stalls remains constant regardless of weight,
airplane loading, etc.
D. STALLS AND SPINS
1) An airplane can be stalled at any airspeed in any flight attitude. A stall results
whenever the critical angle of attack is exceeded.
2) An airplane in a given configuration will stall at the same indicated airspeed
regardless of altitude because the airspeed indicator is directly related to air density.
3) An airplane spins when one wing is less stalled than the other wing.
i. To enter a spin, an airplane must always be stalled first.
E. FROST
1) Frost forms when the temperature of the collecting surface is at or below the
dewpoint of the adjacent air, and the dewpoint is below freezing.
i. The water vapor sublimates directly as ice crystals on the wing surface.
2) Frost on wings disrupts the smooth airflow over the airfoil by causing early airflow
separation from the wing. This
i. Decreases lift, and
ii. Causes friction and increases drag.
3) Frost may make it difficult or impossible for an airplane to take off.
