TC PPL Written Exam: General
Knowledge (Answered) 2025/2026.
How does an airplane acheive lift?
Lift acts in the direction of low pressure
Describe the direction of wing tip vortices.
Left wing; clockwise
Right wing; counterclockwise
What is parasite drag?
What are the sub components of parasite drag?
All parts of the airplane that do not contribute to lift
Sub components:
1) form drag: drag created by the shape of body
2) skin friction: tendency of air flowing over a body to cling to its surface
What is induced drag?
The parts of the aeroplane that are actively producing lift
What is Aileron Drag? How is it corrected on some planes?
The drag produced by the down going aileron. It is corrected with frise and differential ailerons.
Explain the boundary layer, and the 3 parts that it turns into.
Boundary layer: thin sheet of air lying over the surface of the wing
1) laminar layer: it's basically the boundary layer
2) transition point: the point of transition between laminar and turbulent
3) turbulent layer: due to friction the laminar layer become turbulent
What's the angle of incidence?
Angle of the wing to the longitudinal axis
Explain wing fences.
Fin-like vertical surfaces attached to the upper surface of the wing, used to control airflow. They
prevent air to travel towards the tip of the wing during high angles of attack.
What are slots?
They are passageways built into the wing. At high angles of attack. The air flows through the slot and
over the wing to smooth out eddies.
What are slats?
Auxiliary airfoils fitted to leading edge of wing. At high angles of attack they automatically move out
and head of the wing. It helps to smooth out eddies that are creeping up the wings.
, Explain static stability?
The tendency of an aeroplane to return to original position after being disturbed.
Explain dynamic stability?
Is the overall tendency of an aeroplane to return to original position following a series of damped
out oscillations.
Positive stability
Aeroplane will restore to original position.
Neutral stability
Aeroplane will neither return nor move further away from original position.
Negative stability
Aeroplane will move further away from original position.
What's the benefit of dihedral wing?
Increased lateral stability.
Asymmetric thrust
At higher angles of attack, the propellers blades have a greater angle of attack, which creates more
lift on the right side of the propeller and results in yaw of aeroplane to the left
What is Vy?
Best rate of clime, most altitude in the LEAST TIME
What is Vx?
Best angle of climb, most altitude in a GIVEN DISTANCE
List all factors that affect a stall.
- weight
- centre of gravity
- turbulence
- turns ---> you can calculate the stall speed by: normal stall speed x load factor in bank
- flaps
- snow, frost, and ice
What are critical surfaces? List them.
Anything used to produce lift.
- wings
- control surfaces
- rotors
- propellers
- horizontal stabilizers
- vertical stabilizers
- etc.
Knowledge (Answered) 2025/2026.
How does an airplane acheive lift?
Lift acts in the direction of low pressure
Describe the direction of wing tip vortices.
Left wing; clockwise
Right wing; counterclockwise
What is parasite drag?
What are the sub components of parasite drag?
All parts of the airplane that do not contribute to lift
Sub components:
1) form drag: drag created by the shape of body
2) skin friction: tendency of air flowing over a body to cling to its surface
What is induced drag?
The parts of the aeroplane that are actively producing lift
What is Aileron Drag? How is it corrected on some planes?
The drag produced by the down going aileron. It is corrected with frise and differential ailerons.
Explain the boundary layer, and the 3 parts that it turns into.
Boundary layer: thin sheet of air lying over the surface of the wing
1) laminar layer: it's basically the boundary layer
2) transition point: the point of transition between laminar and turbulent
3) turbulent layer: due to friction the laminar layer become turbulent
What's the angle of incidence?
Angle of the wing to the longitudinal axis
Explain wing fences.
Fin-like vertical surfaces attached to the upper surface of the wing, used to control airflow. They
prevent air to travel towards the tip of the wing during high angles of attack.
What are slots?
They are passageways built into the wing. At high angles of attack. The air flows through the slot and
over the wing to smooth out eddies.
What are slats?
Auxiliary airfoils fitted to leading edge of wing. At high angles of attack they automatically move out
and head of the wing. It helps to smooth out eddies that are creeping up the wings.
, Explain static stability?
The tendency of an aeroplane to return to original position after being disturbed.
Explain dynamic stability?
Is the overall tendency of an aeroplane to return to original position following a series of damped
out oscillations.
Positive stability
Aeroplane will restore to original position.
Neutral stability
Aeroplane will neither return nor move further away from original position.
Negative stability
Aeroplane will move further away from original position.
What's the benefit of dihedral wing?
Increased lateral stability.
Asymmetric thrust
At higher angles of attack, the propellers blades have a greater angle of attack, which creates more
lift on the right side of the propeller and results in yaw of aeroplane to the left
What is Vy?
Best rate of clime, most altitude in the LEAST TIME
What is Vx?
Best angle of climb, most altitude in a GIVEN DISTANCE
List all factors that affect a stall.
- weight
- centre of gravity
- turbulence
- turns ---> you can calculate the stall speed by: normal stall speed x load factor in bank
- flaps
- snow, frost, and ice
What are critical surfaces? List them.
Anything used to produce lift.
- wings
- control surfaces
- rotors
- propellers
- horizontal stabilizers
- vertical stabilizers
- etc.
