Lecture 11 Flashcards
What are the parts of a helicopter?*
Rotor mast
Main rotor
Tail rotor
Cockpit
Vertical stabilizer
Landing skids
Engine and transmission
Where do the four forces act when a helicopter is in a hover?*
In directional flight?*
Thrust and lift act vertically up
Weight and drag act vertically down
Lift acts vertically up
Thrust acts in the direction the aircraft is flying
Weight acts vertically down
Drag acts opposite to the direction the aircraft is flying
What does the collective stick do when the pilot moves it?
Where is it located?
Pull up on the stick to go up
Push down on the stick to go down
On the pilot’s left side
What increases the lift of a helicopter when the collective stick is moved?
The increase in AOA of all of the main rotor blades collectively
Hint: collective, all move collectively
What does the cyclic stick do when the pilot moves it?
Where is it located?
Push forward to go forward
Pull back to slow down or fly backwards
Move/translate left to go left
Move/translate right to go right
In front of the pilot
What can pulling back on the cyclic stick be bad?
Rearward flight can cause the rotor blades to hit the tail boom, or cause the tail rotor to strike the ground
The _____ a helicopter tries to go forward, the further _____ the nose comes as more of the _____ effect is diverted from _____ and into _____.
faster
down
Bernoulli
lift
thrust
Describe how the cyclic stick changes blade pitch
Raises, lowers, or tilts the non-rotating plate
Rotating swash plate is correspondingly raised, lowered, or tilted
As the rotating swash plate is moved, the pitch change links that spin with the rotor blades, are also raised or lowered
This changes the pitch of the blades
What are the three parts of the rotor mast that change blade angle?
Pitch change links
Rotating swash plate
Non-rotating swash plate
The controls of a helicopter go through a device called a _____.
“Swash Plate”
Helicopter rotors run at a _____ in flight.
constant RPM
Why do main rotors turn at a constant RPM?
Increasing rotor speed to get more lift takes too long, changing the pitch gives instantaneous lift response
The rotor blades need centrifugal force to hold them out straight or else the lift forces will fold up or break the blades
Main rotor blades are very flexible, with no centrifugal force to hold them straight what will the blades do when not spinning?
Droop
Blades _____ when they are spinning and put under a lift load.
pull up, or “cone”
How do the blades on a helicopter remain straight?
The spinning rotor blades generate a centrifugal force that keeps the blades straight and prevents the blades from folding up or breaking
