SIFT ARMY AVIATION KNOWLEDGE
EXAM QUESTIONS WITH COMPLETE
SOLUTION
The decrease in fluid pressure that occurs when a fluid passes through a
confined segment (or choke) of a pipe. - ANSWER The Venturi effect
ANSWER: Cyclic Control is used to control the direction or tilt of an aircraft.
The Collective is - ANSWER used to regulate the pitch angle of all the primary
rotor blades together.
The throttle is used to control the power generated by the engine.
The anti-torque pedals are used to adjust the aircraft's yaw and where it is
pointed.
ANSWER: The airfoil is ______ either the rotor blades or the horizontal
stabilizers.
The angle between an airfoil's chord line and its direction of motion relative to
the air (Aerodynamic Angle) is known as... ANSWER Angle of Attack
The angle between each blade's chord line and the rotor system's plane of
rotation (Mechanical Angle) is known as... - ANSWER Angle of incidence
Chord Line is a straight line that intersects the leading and trailing edges of an
airfoil.
The angle formed between the line perpendicular to the mast and the blades in
motion. - ANSWER Coning angle.
Autorotation occurs when the engine loses power and the rotors are angled
down so that air keeps them spinning. The freewheeling unit disengaged.
,The blade span is ____________. - Determine the length from the blade tip to
the drive shaft.
What is parasitic drag? - ANSWER Drag from components that don't produce
lift (wheels, fuselage).
A spinning body spins at the same speed until acted on by an external force,
which is known as the Coriolis force.
_____ is the unequal lift across the rotor disk caused by the differential in air
velocity across the advancing blade half vs the retreating blade half of the rotor
disk surface. - ANSWER dissymmetry of lift
The driven region is _____the blade tips and generally _____ percent of the
radius - ANSWER: 30
For helicopters with a primary rotor disk that spins counterclockwise, the
airflow speed occurs when each blade reaches the position of ______ -
ANSWER maximum, three and nine o'clock.
What kind of drag is created by lift? - ANSWER Induced Drag
What sort of helicopter design employs a ducted fan instead of a tail rotor to
counteract torque effects? - ANSWER THE NOTOR
Which pitot-static apparatus applies both pitot and static pressure? - ANSWER
Airspeed indicator
What is the key principle used to counterbalance the main rotor torque with
NOTAR. - ANSWER Coanda Effect
What are the four components of risk management? - ANSWER: Pilot, aircraft,
surroundings, and external pressures
, What is the preferred mode of ground mobility for a helicopter at an airport? -
ANSWER: Air taxi
Helicopters experience efficient translational lift while transitioning to forward
flight at roughly _____ to _____ knots—ANSWER 16, 24.
What aerodynamic situation can develop when a helicopter descends at more
than 300 fpm with 20 to 100% power and an airspeed less than effective
translational lift? - ANSWER settling with power.
Driven Region - Answer Has the effect of slowing the rotor's rotation.
Driving Region - ANSWER Supply's focus.
While transitioning to forward flight at roughly 16 to 24 mph, the helicopter
passes through - ANSWER Effective Translational Lift
When a force is applied to one side of a spinning object, it causes an action that
is about 90° in the direction of rotation from the point of application. The action
is called gyroscopic precession.
When the helicopter is in the state of hover, the resultant lift is exactly equal to
the weight.
Induced flow or downwash is the flow of air traveling down through the rotors.
________ is the improved efficiency of the rotor disk due to airflow
interference near the ground. - ANSWER In-Ground Effect (IGE)
In forward flight, the tail rotor continues to push to the right, and the helicopter
forms a slight angle with the wind while the rotors are level and the slip ball is
in the center. This is known as the intrinsic sideslip.
EXAM QUESTIONS WITH COMPLETE
SOLUTION
The decrease in fluid pressure that occurs when a fluid passes through a
confined segment (or choke) of a pipe. - ANSWER The Venturi effect
ANSWER: Cyclic Control is used to control the direction or tilt of an aircraft.
The Collective is - ANSWER used to regulate the pitch angle of all the primary
rotor blades together.
The throttle is used to control the power generated by the engine.
The anti-torque pedals are used to adjust the aircraft's yaw and where it is
pointed.
ANSWER: The airfoil is ______ either the rotor blades or the horizontal
stabilizers.
The angle between an airfoil's chord line and its direction of motion relative to
the air (Aerodynamic Angle) is known as... ANSWER Angle of Attack
The angle between each blade's chord line and the rotor system's plane of
rotation (Mechanical Angle) is known as... - ANSWER Angle of incidence
Chord Line is a straight line that intersects the leading and trailing edges of an
airfoil.
The angle formed between the line perpendicular to the mast and the blades in
motion. - ANSWER Coning angle.
Autorotation occurs when the engine loses power and the rotors are angled
down so that air keeps them spinning. The freewheeling unit disengaged.
,The blade span is ____________. - Determine the length from the blade tip to
the drive shaft.
What is parasitic drag? - ANSWER Drag from components that don't produce
lift (wheels, fuselage).
A spinning body spins at the same speed until acted on by an external force,
which is known as the Coriolis force.
_____ is the unequal lift across the rotor disk caused by the differential in air
velocity across the advancing blade half vs the retreating blade half of the rotor
disk surface. - ANSWER dissymmetry of lift
The driven region is _____the blade tips and generally _____ percent of the
radius - ANSWER: 30
For helicopters with a primary rotor disk that spins counterclockwise, the
airflow speed occurs when each blade reaches the position of ______ -
ANSWER maximum, three and nine o'clock.
What kind of drag is created by lift? - ANSWER Induced Drag
What sort of helicopter design employs a ducted fan instead of a tail rotor to
counteract torque effects? - ANSWER THE NOTOR
Which pitot-static apparatus applies both pitot and static pressure? - ANSWER
Airspeed indicator
What is the key principle used to counterbalance the main rotor torque with
NOTAR. - ANSWER Coanda Effect
What are the four components of risk management? - ANSWER: Pilot, aircraft,
surroundings, and external pressures
, What is the preferred mode of ground mobility for a helicopter at an airport? -
ANSWER: Air taxi
Helicopters experience efficient translational lift while transitioning to forward
flight at roughly _____ to _____ knots—ANSWER 16, 24.
What aerodynamic situation can develop when a helicopter descends at more
than 300 fpm with 20 to 100% power and an airspeed less than effective
translational lift? - ANSWER settling with power.
Driven Region - Answer Has the effect of slowing the rotor's rotation.
Driving Region - ANSWER Supply's focus.
While transitioning to forward flight at roughly 16 to 24 mph, the helicopter
passes through - ANSWER Effective Translational Lift
When a force is applied to one side of a spinning object, it causes an action that
is about 90° in the direction of rotation from the point of application. The action
is called gyroscopic precession.
When the helicopter is in the state of hover, the resultant lift is exactly equal to
the weight.
Induced flow or downwash is the flow of air traveling down through the rotors.
________ is the improved efficiency of the rotor disk due to airflow
interference near the ground. - ANSWER In-Ground Effect (IGE)
In forward flight, the tail rotor continues to push to the right, and the helicopter
forms a slight angle with the wind while the rotors are level and the slip ball is
in the center. This is known as the intrinsic sideslip.
