FIRST PUBLISH SEPTEMBER 2024
SIFT Army aviation knowledge Exam
Questions and Answers |100% Pass
______ is the reduction in fluid pressure that results when a fluid flows through a constricted section (or
choke) of a pipe. - Answer✔✔-The Venturi Effect
Cyclic Control is - Answer✔✔-used to control the direction or tilt of aircraft
The Collective is - Answer✔✔-used to control the pitch angle of all the main rotor blades collectively
Throttle is - Answer✔✔-used to control the power produced by the engine
Anti-torque pedals are - Answer✔✔-used to control the yaw of the aircraft and where it is pointing
Airfoil is ______ - Answer✔✔-Either the rotor blades themselves or the horizontal stabilizers.
The angle between the chord line of an airfoil and the airfoil's direction of motion relative to the air
(Aerodynamic Angle) is called .... - Answer✔✔-Angle of Attack
The angle between the chord line of each blade and the rotor system's plane of rotation (Mechanical
Angle) is called .... - Answer✔✔-angle of incidence
Chord Line is - Answer✔✔-a straight-line intersecting leading and trailing edges of the airfoil
The is the angle between the line perpendicular to the mast and the blades in motion. - Answer✔✔-
Coning angle
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FIRST PUBLISH SEPTEMBER 2024
Autorotation is - Answer✔✔-loss of engine power, angle down so that air keeps the rotors spinning. The
freewheeling unit disconnected
Blade Span is _____________ - Answer✔✔-the length from the tip of the blade to the drive shaft
What is parasite drag? - Answer✔✔-Drag from components that don't create lift (Wheels, Fuselage)
A rotating body spins at the same speed unless acted upon by an external force is called - Answer✔✔-
Coriolis force
_____ is the unequal lift across the rotor disk resulting from the difference in the velocity of air over the
advancing blade half and the velocity of air over the retreating blade half of the rotor disk area. -
Answer✔✔-dissymmetry of lift
The driven region is _____the blade tips and normally _____ percent of the radius - Answer✔✔-nearest
from, 30
For helicopters with a main rotor disk that spins counter-clockwise, the airflow speed happens when
each blade reaches the position ______ - Answer✔✔-maximum, three and nine o'clock
What type of drag is caused by lift? - Answer✔✔-Induced drag
What type of helicopter design uses a ducted fan in place of a tail rotor to cancel the torque effect? -
Answer✔✔-the NOTOR
Which pitot-static instrument makes use of both pitot and static pressure? - Answer✔✔-Airspeed
indicator
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, EMILLYCHARLOTTE 2024/2025 ACADEMIC YAER ©2024 EMILLYCHARLOTTE. ALL RIGHTS RESERVED
FIRST PUBLISH SEPTEMBER 2024
What is the primary principle to counteract the main rotor torque with NOTAR? - Answer✔✔-Coanda
effect
What are the four elements of risk management? - Answer✔✔-pilot, aircraft, environment, and external
pressures
What is the preferred method of ground movement for a helicopter on airports? - Answer✔✔-Air Taxi
Helicopter's experience effective translational lift while transitioning to forward flight at approximately
_____ to _____ knots - Answer✔✔-16, 24
When a helicopter is descending at more than 300 fpm, has 20 to 100 percent power, and an airspeed
less than effective translational lift, what aerodynamic condition can occur? - Answer✔✔-Settling with
power
Driven Region - Answer✔✔-Has the effect of slowing the rotor's spin.
Driving Region - Answer✔✔-Supply's thrust.
While transitioning to forward flight at about 16 to 24 knots, the helicopter goes through - Answer✔✔-
Effective Translational Lift
When a force is applied to one side of a spinning object, an action occurs approximately 90° in the
direction of rotation from the point where the force is applied. The action is called - Answer✔✔-
gyroscopic precession
When the helicopter is in the state of hover - Answer✔✔-the resultant lift is exactly equal to the weight
Induced Flow or Downwash is - Answer✔✔-the flow of air going down through the rotors
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