Aerodynamics & Aircraft Performance Flashcards

Which of the four aerodynamic forces acts opposite to the direction of flight?

Answer: Drag

Drag opposes the direction of flight and must be overcome by thrust to maintain airspeed.

According to Bernoulli's principle, what happens to air pressure as airspeed over a wing increases?

Answer: Pressure decreases

Bernoulli's principle states that as fluid velocity increases, static pressure decreases, which generates lift on the upper wing surface.

What is the angle of attack?

Answer: The angle between the chord line and the relative wind

Angle of attack is the angle between the wing's chord line and the relative wind (direction of oncoming airflow).

What occurs when a wing exceeds its critical angle of attack?

Answer: The wing stalls and lift decreases dramatically

Exceeding the critical angle of attack causes airflow to separate from the upper wing surface, resulting in a sudden and dramatic loss of lift (stall).

What type of drag is caused by the generation of lift?

Answer: Induced drag

Induced drag is a byproduct of lift generation; it results from wingtip vortices and increases as the angle of attack increases.

As altitude increases, how does air density affect aircraft performance?

Answer: Thinner air reduces engine power and requires higher true airspeed to maintain lift

Higher altitude means lower air density, which reduces engine power output and requires a higher true airspeed to generate the same lift, degrading overall performance.

What is the primary purpose of an aircraft's flaps?

Answer: To increase lift and drag for slower flight and shorter landings

Flaps increase both lift and drag, enabling slower approach and landing speeds and reducing the runway distance required.