SIFT Study Guide ACTUAL Exam
Questions and CORRECT Answers
The four forces acting on helicopter in forward flight are...? - CORRECT ANSWER -
Thrust, drag, weight, lift
Bernoulli's Principle or the "venturi effect" - CORRECT ANSWER - As air flows over
upper surface of airfoil, camber (curvature) of airfoil causes increase in speed of airflow which
decreased pressure. Pressure is increased on bottom and this gives lift.
Newtons Third Law of Motion and how it applies to helicopters - CORRECT ANSWER -
"for every action there is an equal and opposite reaction"
*small amount of lift is provided by the rotor blades lower surface deflecting air downward, thus
having a small force upward
Weight is overcome by ______ and this is accomplished by increasing the ____ _____ of the
main rotor blades. - CORRECT ANSWER - thrust;
pitch angle
The tail rotor produces thrust and is variable through use of antitorque pedals which control the
helicopters _______. - CORRECT ANSWER - yaw
Drag always acts parallel to the relative _______.
Total drag is composed of three types of drag.... - CORRECT ANSWER - wind
profile, induced, parasite
,What is Parasite drag? - CORRECT ANSWER - any "parasite" on the aircraft that creates
a drag.
Ex: low air pressure in tires, skin friction (rough surface that creates resistance)
What is profile drag? - CORRECT ANSWER - drag produced by shape of the aircraft
What is induced drag? - CORRECT ANSWER - when at the back of the wing, air flowing
fast over the top meets air flowing slowly underneath.
Newtons First Law of Motion states that.... - CORRECT ANSWER - an object at rest will
stay at rest, and in motion will remain in motion at constant velocity unless acted upon by an
unbalanced force
Four Types of Friction: - CORRECT ANSWER - 1. Sliding/Kinetic Friction
2. Fluid Friction (through air or water)
3. Rolling Friction: when object rolls instead of slides across surface
4.Static Friction
Newtons Second Law of Motion states that... - CORRECT ANSWER - When object is
acted upon by constant force, its resulting acceleration is inversely proportional to the mass and
directly proportional to the applied force
F=ma
Newtons Law of Universal Gravitation equation - CORRECT ANSWER -
Fg=(Gm1m2)/d^2
G=gravitational constant=6.67x10^-11
, Two objects a distance of "d" apart. What happens to force b/w the two objects if you increase d
by a factor of 4? - CORRECT ANSWER - You decrease the force by a factor of 16
Aircraft weight and balance: what does each acronym stand for and mean?
1. MEW
2.OEW
3. AUW
4. MLW
5. MZFW
6. MTOW
7. MRW - CORRECT ANSWER - 1. Manufacturers Empty Weight: total weight of aircraft
as it was built and meant to fly, and does not include fuel or fluids, passengers or other things
2. Operating Empty Weight: the MEW + weight of crew, fluids, unusable fuel, and equipment
required for flight. Does not include baggage, passengers or usable fuel
3. All Up Weight: (aircrafts gross weight)total aircraft weight at any given moment during a
flight. Decreases as flight time proceeds (fuel is depleted)
4. Maximum landing weight: weight limit for landing. exceeding may harm landing gear
5. Maximum Zero Fuel Weight: limit weight of an aircraft with its contents and includes
unusable fuel...excludes weight of usable fuel and consumable liquids on board
6. Max Takeoff Weight: weight limit for takeoff. Exceeding this limit increases power required
for takeoff
7. Maximum Ramp Weight: weight limit for an aircraft to taxi or be towed on the ground
Questions and CORRECT Answers
The four forces acting on helicopter in forward flight are...? - CORRECT ANSWER -
Thrust, drag, weight, lift
Bernoulli's Principle or the "venturi effect" - CORRECT ANSWER - As air flows over
upper surface of airfoil, camber (curvature) of airfoil causes increase in speed of airflow which
decreased pressure. Pressure is increased on bottom and this gives lift.
Newtons Third Law of Motion and how it applies to helicopters - CORRECT ANSWER -
"for every action there is an equal and opposite reaction"
*small amount of lift is provided by the rotor blades lower surface deflecting air downward, thus
having a small force upward
Weight is overcome by ______ and this is accomplished by increasing the ____ _____ of the
main rotor blades. - CORRECT ANSWER - thrust;
pitch angle
The tail rotor produces thrust and is variable through use of antitorque pedals which control the
helicopters _______. - CORRECT ANSWER - yaw
Drag always acts parallel to the relative _______.
Total drag is composed of three types of drag.... - CORRECT ANSWER - wind
profile, induced, parasite
,What is Parasite drag? - CORRECT ANSWER - any "parasite" on the aircraft that creates
a drag.
Ex: low air pressure in tires, skin friction (rough surface that creates resistance)
What is profile drag? - CORRECT ANSWER - drag produced by shape of the aircraft
What is induced drag? - CORRECT ANSWER - when at the back of the wing, air flowing
fast over the top meets air flowing slowly underneath.
Newtons First Law of Motion states that.... - CORRECT ANSWER - an object at rest will
stay at rest, and in motion will remain in motion at constant velocity unless acted upon by an
unbalanced force
Four Types of Friction: - CORRECT ANSWER - 1. Sliding/Kinetic Friction
2. Fluid Friction (through air or water)
3. Rolling Friction: when object rolls instead of slides across surface
4.Static Friction
Newtons Second Law of Motion states that... - CORRECT ANSWER - When object is
acted upon by constant force, its resulting acceleration is inversely proportional to the mass and
directly proportional to the applied force
F=ma
Newtons Law of Universal Gravitation equation - CORRECT ANSWER -
Fg=(Gm1m2)/d^2
G=gravitational constant=6.67x10^-11
, Two objects a distance of "d" apart. What happens to force b/w the two objects if you increase d
by a factor of 4? - CORRECT ANSWER - You decrease the force by a factor of 16
Aircraft weight and balance: what does each acronym stand for and mean?
1. MEW
2.OEW
3. AUW
4. MLW
5. MZFW
6. MTOW
7. MRW - CORRECT ANSWER - 1. Manufacturers Empty Weight: total weight of aircraft
as it was built and meant to fly, and does not include fuel or fluids, passengers or other things
2. Operating Empty Weight: the MEW + weight of crew, fluids, unusable fuel, and equipment
required for flight. Does not include baggage, passengers or usable fuel
3. All Up Weight: (aircrafts gross weight)total aircraft weight at any given moment during a
flight. Decreases as flight time proceeds (fuel is depleted)
4. Maximum landing weight: weight limit for landing. exceeding may harm landing gear
5. Maximum Zero Fuel Weight: limit weight of an aircraft with its contents and includes
unusable fuel...excludes weight of usable fuel and consumable liquids on board
6. Max Takeoff Weight: weight limit for takeoff. Exceeding this limit increases power required
for takeoff
7. Maximum Ramp Weight: weight limit for an aircraft to taxi or be towed on the ground
