Aerodynamics and Aircraft Systems 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 and Aircraft Systems flashcards as text
What is a phugoid oscillation?
Answer: A long-period oscillation in pitch where the aircraft trades airspeed for altitude
A phugoid is a long-period (20–100 seconds) longitudinal oscillation where the aircraft exchanges kinetic and potential energy, with relatively little change in angle of attack.
Dutch roll is an oscillatory motion that primarily couples which two axes?
Answer: Roll and yaw
Dutch roll is a combined lateral-directional oscillation involving roll and yaw, typically experienced in swept-wing aircraft with high dihedral effect.
If an aircraft enters a 60-degree banked level turn, the stall speed increases by a factor of approximately:
Answer: 1.41
At 60° of bank, the load factor is 2 g, and stall speed increases by the square root of the load factor (√2 ≈ 1.41).
What aerodynamic phenomenon causes adverse yaw during a roll input?
Answer: The down-going aileron produces more induced drag than the up-going aileron
The aileron deflected downward (on the rising wing) generates more lift and therefore more induced drag, yawing the nose toward the descending wing — opposite to the intended turn direction.
In ground effect, induced drag is reduced primarily because:
Answer: The ground interrupts wingtip vortex formation, reducing downwash and induced drag
Ground effect restricts wingtip vortex development, reducing downwash behind the wing, which decreases induced angle of attack and induced drag.
P-factor (asymmetric blade effect) is most pronounced in a single-engine propeller aircraft when:
Answer: At a high angle of attack with the propeller developing significant thrust
At high angles of attack, the descending propeller blade has a greater effective angle of attack than the ascending blade, producing more thrust on one side and causing yaw.
The 'coffin corner' refers to the flight envelope condition where:
Answer: The low-speed buffet and high-speed buffet margins converge at high altitude
At high altitude, the low-speed (aerodynamic) buffet boundary and the high-speed (Mach) buffet boundary converge, leaving a very narrow speed range for safe flight.