SIFT ARMY AVIATION QUESTIONS
WITH VERIFIED ANSWERS
An airfoil is a blade that cuts through air, allowing air to move both above and
below it.
The top of an airfoil is cambered.
Why is the top of an airfoil cambered? - ANSWER To let air to swiftly pass
past the airfoil, creating low pressure.
What happens to the air beneath an airfoil? - ANSWER Has a shorter distance
to travel and is slower, resulting in high-pressure
Lift is the upward force caused by the difference in air pressure above and
below the airfoil.
The angle of incidence (pitch angle) is the angle between the cord line and the
direction of the rotor's rotation.
The angle of Attack (AOA) is the angle between the chord line and the direction
of the oncoming air.
To create lift, you need a ______ AOA - ANSWER Positive.
How do you produce a positive AOA? ANSWER: The front of the blade should
be lifted above the back, relative to the wind.
What type of airfoil can generate lift with zero or negative AOA? Answer:
cambered or nonsymmetrical.
Weight is a crucial aspect in flight because: - ANSWER You must generate
enough force to get the weight off the ground, necessitating additional lift.
What three causes can induce a weight shift during flight? - ANSWER Strong
winds, poor weather conditions, and banking
, What is the most common reason for a weight shift during flight? - ANSWER
Banking the helicopter.
What else must grow as a bank's angle rises? - ANSWER The angle of the
airfoil that generates higher lift
Load factor (G load) - ANSWER Additional strain caused by banking and
raising the angle of the airfoil.
G load equation: ANSWER G = L1 / L0
G - ANSWER load factor
L1 - ANSWER: Actual load on rotor blades.
L0 - ANSWER: The helicopter's resting or usual load
Thrust is the force that causes the helicopter to move horizontally.
How do you generate thrust? - ANSWER Converting lift by adjustments in
pitch angle and AOA
Drag - ANSWER The opposing force of push
What are the three subtypes of drag? - ANSWER Profile: parasitic and induced
ANSWER: Parasitic drag increases with airspeed and is the dominant type of
drag at high speeds.
ANSWER Profile drag is similar to parasitic drag, but it solely considers the
drag caused by the frictional resistance of spinning airfoils. Profile drag stays
constant throughout flight, neither overwhelming nor negligible.
WITH VERIFIED ANSWERS
An airfoil is a blade that cuts through air, allowing air to move both above and
below it.
The top of an airfoil is cambered.
Why is the top of an airfoil cambered? - ANSWER To let air to swiftly pass
past the airfoil, creating low pressure.
What happens to the air beneath an airfoil? - ANSWER Has a shorter distance
to travel and is slower, resulting in high-pressure
Lift is the upward force caused by the difference in air pressure above and
below the airfoil.
The angle of incidence (pitch angle) is the angle between the cord line and the
direction of the rotor's rotation.
The angle of Attack (AOA) is the angle between the chord line and the direction
of the oncoming air.
To create lift, you need a ______ AOA - ANSWER Positive.
How do you produce a positive AOA? ANSWER: The front of the blade should
be lifted above the back, relative to the wind.
What type of airfoil can generate lift with zero or negative AOA? Answer:
cambered or nonsymmetrical.
Weight is a crucial aspect in flight because: - ANSWER You must generate
enough force to get the weight off the ground, necessitating additional lift.
What three causes can induce a weight shift during flight? - ANSWER Strong
winds, poor weather conditions, and banking
, What is the most common reason for a weight shift during flight? - ANSWER
Banking the helicopter.
What else must grow as a bank's angle rises? - ANSWER The angle of the
airfoil that generates higher lift
Load factor (G load) - ANSWER Additional strain caused by banking and
raising the angle of the airfoil.
G load equation: ANSWER G = L1 / L0
G - ANSWER load factor
L1 - ANSWER: Actual load on rotor blades.
L0 - ANSWER: The helicopter's resting or usual load
Thrust is the force that causes the helicopter to move horizontally.
How do you generate thrust? - ANSWER Converting lift by adjustments in
pitch angle and AOA
Drag - ANSWER The opposing force of push
What are the three subtypes of drag? - ANSWER Profile: parasitic and induced
ANSWER: Parasitic drag increases with airspeed and is the dominant type of
drag at high speeds.
ANSWER Profile drag is similar to parasitic drag, but it solely considers the
drag caused by the frictional resistance of spinning airfoils. Profile drag stays
constant throughout flight, neither overwhelming nor negligible.
