PRIVATE HELICOPTER STUDY SHEET 2026
TEST PAPER QUESTIONS AND SOLUTIONS
GUARANTEED TO PASS
●● Three types of drag
(Define and explain).
Answer: Profile drag- seperated into skin friction, and form drag.
*skin friction- caused by surface roughness on the airfoil. a thin layer of
air clings to the surface and creates small eddies that add to drag
*form drag- size and shape of the airfoil. caused by terbulant wake
which results from seperation of airflow from the surface of the
structure.
Induced drag- The componant of lift acting in the rearward direction. a
byproduct of lift.
Parasite drag- caused by all the non-lifting componants of the aircraft
such as the cabin, and tailboom
●● Which types of drag increase with airspeed? which decreas?.
Answer: -parasite drag increases with airspeed
-profile drag stays relatively constant with small increase with airspeed
,-induced drag decreases with airspeed due to the reduction in angle of
attack.
●● Total drag curve.
Answer: All three drags combined for the amount of drag for an airspeed
●● L/D max.
Answer: The max lift to drag ratio.
(greates amount of lift for least amount of drag)
●● The lift generated by an airfoil depends on what factors?
(lift formula).
Answer: CL S (1/2P) V^2
-Coefficient of lift
*Angle of attack
*shape of the airfoil
-Surface area
-1/2 ROW (Density of air)
-Velocity of airflow squared
●● Bernoullis Principle
(how does it effect the helicopter).
,Answer: As velocity increases, pressure decreases.
-The air flowing up over the airfoil has an increased velocity and
therefore reduced pressure, giving the wing a lifting force.
●● Magnus Effect.
Answer: The upward force produced by the low pressure area on the top
of the airfoil.
●● Newtons third law
(how does it effect the helicopter).
Answer: For every action there is an equeal and opposite reaction.
-The air that is underneath the airfoil is deflected downward. the equal
and opposite reaction is for the airfoil to be deflected upward.
●● Blade Span.
Answer: The length of the rotor blade from the center of rotation to the
blade tip.
●● Chord line.
Answer: The imaginary Straight line connecting the leading edge to the
trailing edge of the airfoil.
●● Mean chamber line.
, Answer: A line equadistant from the upper and lower surface of the
airfoil, connecting the leading edge and trailiing edge of the airfoil.
●● Leading edge.
Answer: The front edge of the airfoil
●● Trailing edge.
Answer: the back end of the airfoil
●● Flightpath Velocity.
Answer: the speed and rotaion of the airfoil passing through the air
●● Induced flow.
Answer: The downward flow of air through the rotor disk.
●● Relative wind.
Answer: The flow of air directly hitting the airfoil
●● Resultant relative wind.
Answer: Relative wind modified by induced fow.
●● Angle of attack.
TEST PAPER QUESTIONS AND SOLUTIONS
GUARANTEED TO PASS
●● Three types of drag
(Define and explain).
Answer: Profile drag- seperated into skin friction, and form drag.
*skin friction- caused by surface roughness on the airfoil. a thin layer of
air clings to the surface and creates small eddies that add to drag
*form drag- size and shape of the airfoil. caused by terbulant wake
which results from seperation of airflow from the surface of the
structure.
Induced drag- The componant of lift acting in the rearward direction. a
byproduct of lift.
Parasite drag- caused by all the non-lifting componants of the aircraft
such as the cabin, and tailboom
●● Which types of drag increase with airspeed? which decreas?.
Answer: -parasite drag increases with airspeed
-profile drag stays relatively constant with small increase with airspeed
,-induced drag decreases with airspeed due to the reduction in angle of
attack.
●● Total drag curve.
Answer: All three drags combined for the amount of drag for an airspeed
●● L/D max.
Answer: The max lift to drag ratio.
(greates amount of lift for least amount of drag)
●● The lift generated by an airfoil depends on what factors?
(lift formula).
Answer: CL S (1/2P) V^2
-Coefficient of lift
*Angle of attack
*shape of the airfoil
-Surface area
-1/2 ROW (Density of air)
-Velocity of airflow squared
●● Bernoullis Principle
(how does it effect the helicopter).
,Answer: As velocity increases, pressure decreases.
-The air flowing up over the airfoil has an increased velocity and
therefore reduced pressure, giving the wing a lifting force.
●● Magnus Effect.
Answer: The upward force produced by the low pressure area on the top
of the airfoil.
●● Newtons third law
(how does it effect the helicopter).
Answer: For every action there is an equeal and opposite reaction.
-The air that is underneath the airfoil is deflected downward. the equal
and opposite reaction is for the airfoil to be deflected upward.
●● Blade Span.
Answer: The length of the rotor blade from the center of rotation to the
blade tip.
●● Chord line.
Answer: The imaginary Straight line connecting the leading edge to the
trailing edge of the airfoil.
●● Mean chamber line.
, Answer: A line equadistant from the upper and lower surface of the
airfoil, connecting the leading edge and trailiing edge of the airfoil.
●● Leading edge.
Answer: The front edge of the airfoil
●● Trailing edge.
Answer: the back end of the airfoil
●● Flightpath Velocity.
Answer: the speed and rotaion of the airfoil passing through the air
●● Induced flow.
Answer: The downward flow of air through the rotor disk.
●● Relative wind.
Answer: The flow of air directly hitting the airfoil
●● Resultant relative wind.
Answer: Relative wind modified by induced fow.
●● Angle of attack.
