Aircraft Systems and 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 Aircraft Systems and Aerodynamics flashcards as text
What is the aerodynamic effect of deploying leading-edge slats?
Answer: They increase wing camber and allow higher angles of attack before stall
Leading-edge slats increase wing camber and create a slot that energizes boundary layer airflow, allowing the wing to sustain lift at higher angles of attack and lower speeds.
In a pressurized aircraft, what does 'differential pressure' refer to?
Answer: The difference between cabin pressure and outside ambient pressure
Differential pressure (delta-P) is the difference between the pressurized cabin pressure and the ambient outside air pressure, which determines structural loads on the fuselage.
What is 'propeller slip' in aviation?
Answer: The difference between the theoretical pitch distance traveled and the actual distance advanced per revolution
Propeller slip is the difference between the geometric pitch (theoretical distance advanced per revolution) and the effective pitch (actual distance advanced), caused by the propeller working against air resistance.
What is the relationship between aspect ratio and induced drag?
Answer: Higher aspect ratio produces less induced drag for the same lift
A higher aspect ratio wing generates less induced drag for the same lift coefficient because the wing tips are farther apart, reducing the strength and influence of wingtip vortices.
During engine start, why is it critical to avoid 'hot starting' a turbine engine?
Answer: Excessive turbine inlet temperature during light-off can cause thermal damage to turbine blades
A hot start occurs when turbine inlet temperature exceeds limits during the start sequence, which can cause severe thermal damage to turbine blades and combustion components.
What aerodynamic phenomenon is described by 'ground effect'?
Answer: Reduction of induced drag due to interference with wingtip vortex formation near the ground
Ground effect reduces induced drag by limiting downward airflow from the wingtips, weakening vortices and reducing induced angle of attack when the wing is within approximately one wingspan of the ground.
What is the function of a 'firewall' in a piston aircraft?
Answer: A fire-resistant bulkhead separating the engine compartment from the cabin to contain engine fires
The firewall is a fire-resistant barrier (typically stainless steel) between the engine compartment and the cabin, designed to contain an engine fire for a minimum of 15 minutes.