Principles of Flight and Aerodynamics Flashcards

According to Bernoulli's principle, what happens to static pressure when airflow velocity increases over an airfoil?

Answer: Static pressure decreases

Bernoulli's principle states that as fluid velocity increases, static pressure decreases, creating the pressure differential across the wing that generates lift.

The angle of attack (AOA) is defined as the angle between:

Answer: The relative wind and the chord line of the wing

Angle of attack is measured between the free-stream relative wind and the chord line of the airfoil, regardless of the aircraft's pitch attitude.

Which type of aerodynamic drag increases as airspeed increases?

Answer: Parasite drag

Parasite drag (including form, interference, and skin friction drag) increases proportionally with the square of airspeed.

Induced drag is directly associated with:

Answer: Lift production

Induced drag is a byproduct of lift generation, caused by wingtip vortices that create a rearward tilting of the lift vector.

A stall of an airfoil occurs when:

Answer: The critical angle of attack is exceeded

A stall occurs when the critical angle of attack is exceeded, causing boundary layer separation and a dramatic loss of lift regardless of airspeed.

Which flap type produces the greatest increase in both lift coefficient and wing area?

Answer: Fowler flap

Fowler flaps both extend rearward (increasing wing chord and area) and deflect downward, producing the greatest increase in lift with significant drag.

The lift coefficient (CL) of an airfoil at subsonic speeds is primarily controlled by:

Answer: Angle of attack

The lift coefficient is primarily determined by the angle of attack, which controls the pressure distribution and circulation around the airfoil.