Aerodynamics Flashcards
7 cards from real CPL practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Aerodynamics flashcards as text
What is the primary purpose of a vortex generator on an aircraft wing?
Answer: To re-energize the boundary layer and delay flow separation
Vortex generators create small vortices that mix high-energy air from the free stream into the boundary layer, delaying separation and stall.
Which statement about the boundary layer is correct?
Answer: Turbulent boundary layers are more resistant to separation than laminar ones
Turbulent boundary layers have higher momentum and better resist adverse pressure gradients, making them more resistant to separation despite higher friction.
What is the speed at which the induced drag equals the parasite drag known as?
Answer: All of the above
The speed where induced and parasite drag are equal corresponds to maximum L/D ratio (best glide speed, Vmd), all describing the same condition.
Accelerated stalls are dangerous primarily because they occur at:
Answer: Higher airspeeds than the published 1-G stall speed
Increased load factor in turns or pull-ups raises the stall speed, meaning an accelerated stall can occur at much higher airspeeds than in level flight.
What aerodynamic effect does wing sweep have on stall characteristics?
Answer: It causes tip stall before root stall, worsening pitch-up tendency
Swept wings promote outboard (tip) stall before inboard stall due to spanwise flow toward the tips, causing a dangerous pitch-up at stall.
During a glide, what change increases the glide ratio?
Answer: Increasing L/D ratio
Glide ratio equals the lift-to-drag ratio at the speed flown; achieving a higher L/D (e.g., at Vmd with clean configuration) maximizes the glide distance.
What is the aerodynamic significance of the 'propeller slipstream effect' on a single-engine aircraft?
Answer: It increases dynamic pressure over the tailplane, enhancing elevator effectiveness
Propeller slipstream creates a high-velocity, spiraling airflow that significantly increases dynamic pressure over the horizontal stabilizer, boosting pitch control effectiveness at low speed.