Rotorcraft Aerodynamics UPDATED Actual Exam Questions and CORRECT Answers
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Course
Rotorcraft Aerodynamics
Institution
Rotorcraft Aerodynamics
Rotorcraft Aerodynamics UPDATED
Actual Exam Questions and CORRECT
Answers
How does this limit the rotor blades? (Rigid rotor system) - CORRECT ANSWER- not
free to slide back and forth, not free to move up and down
How are the rotor blades attached to the main rotor hub? (Rigid rotor system)...
Rotorcraft Aerodynamics UPDATED
Actual Exam Questions and CORRECT
Answers
How does this limit the rotor blades? (Rigid rotor system) - CORRECT ANSWER✔✔- not
free to slide back and forth, not free to move up and down
How are the rotor blades attached to the main rotor hub? (Rigid rotor system) - CORRECT
ANSWER✔✔- rigidly attached to the main rotor hub
What are the three main classifications of main rotor systems? - CORRECT ANSWER✔✔-
Rigid, Semi rigid, fully articulating
What does the rotor consist of? - CORRECT ANSWER✔✔- Mast, hub and rotor blades
What is the main rotor system? - CORRECT ANSWER✔✔- The rotating part of a helicopter
which generates lift
What does tilting the rotor plane of rotation do? - CORRECT ANSWER✔✔- causes the
aircraft to move horizontally
What happens when you change the angle of attack of the rotor blades? - CORRECT
ANSWER✔✔- Lift increases or decreases
What is a simplified explanation of how a helicopter flies? - CORRECT ANSWER✔✔- The
rotors are rotating aerofoils that provide lift similar to the way wings provide lift on a fixed
wing aircraft
What can you adjust about the blades? (Rigid rotor system) - CORRECT ANSWER✔✔- The
pitch, via the feathering hinges
How are forces absorbed by the blades? ( Rigid rotor system) - CORRECT ANSWER✔✔-
absorbed by the flexible properties of the blade
,What does the teetering hinge allow? (Semi rigid rotor) - CORRECT ANSWER✔✔- Allows
the main rotor hub to tilt
What happens when one blade flaps up? (Semi rigid rotor) - CORRECT ANSWER✔✔- The
other flaps down
What causes flapping? (Semi rigid rotor) - CORRECT ANSWER✔✔- Disymmetry of lift
What causes greater lift on the advancing blade? What does this cause? (Semi rigid rotor) -
CORRECT ANSWER✔✔- Relative windspeed, greater lift to be developed causing it to rise
up or flap
What happens when the advancing blade becomes the retreating blade?(Semi rigid rotor) -
CORRECT ANSWER✔✔- extra lift is lost and the blades flap downwards
What do the hinges in a fully articulated system allow the rotors to do? - CORRECT
ANSWER✔✔- Move fore and aft as well as up and down
What happens when the blades first start to spin? (Fully articulated rotor system) -
CORRECT ANSWER✔✔- The blades lag until centrifugal force is fully developed
What happens while rotating if there is a reduction in speed?(Fully articulated rotor system) -
CORRECT ANSWER✔✔- Causes to the blades to lead the main rotor hub until forces come
into balance
How many hinges allow for flapping on a fully articulated rotor system? (Fully articulated
rotor system) - CORRECT ANSWER✔✔- one or more horizontal hinges
What is used to reduce shock and limit travel in certain directions? (Fully articulated rotor
system) - CORRECT ANSWER✔✔- various dampers and stops
, What are two advantages of polymer bearings? - CORRECT ANSWER✔✔- Absorb vibration
that'd normally be transferred by steel bearings & don't require regular lubrication
What are flextures? - CORRECT ANSWER✔✔- Hubs and hub components that are made
out of advanced composite materials
What are flextures designed to do? - CORRECT ANSWER✔✔- Take up the forces of blade
hunting and dissymetry of lift by flexing
How many rotor blades do helicopters normally have? - CORRECT ANSWER✔✔- between
2-7
What is produced by the rotating mass of the main rotor blades? - CORRECT ANSWER✔✔-
Torque
When does it increase? What does it try to do? (Torque) - CORRECT ANSWER✔✔-
increases with engine power, tries to spin the fuselage in the opposite direction
What counteracts this force? (torque) - CORRECT ANSWER✔✔- The tail boom and tail
rotor
What controls the countertorque of the tail rotor? (CONTROLS) - CORRECT ANSWER✔✔-
Controlled with foot pedals
What is a Fenestron? - CORRECT ANSWER✔✔- A unique tail rotor design which is a
multiblade ducted fan mounted in the vertical pylon
What does NOTAR stand for? - CORRECT ANSWER✔✔- No Tail Rotor
What does the collective control? - CORRECT ANSWER✔✔- The increase/decrease of the
AOA
What does the collective control do? - CORRECT ANSWER✔✔- Increases/decreases lift
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