Lecture 11

Question 1

In a hover, what are the four forces doing?

Answer 1

Acting vertically.

Question 2

In directional flight, what are the four forces doing?

Answer 2

They seperate. Thrust and drag go diagonal, weight and lift still vertical.

Question 3

Collective stick is what and located where?

Answer 3

Helicopter goes up and down with it. Left of pilot. up=up

Question 4

What increases the lift of the helicopter?

Answer 4

The increase in AOA of all the main rotor blades

Question 5

Cyclic stick does what and located where?

Answer 5

Moves helicopter forward by changing pitch of a rotor blade, tips rotor disk forward.
located in front of pilot. Forward=forward

Question 6

Why is it called the cyclic stick?

Answer 6

It changes the pitch on a rotor blade at only one part of the rotating cycle

Question 7

Why is rearward flight and rapid deceleration dangerous?

Answer 7

The rotor blades can hit the tail boom of the aircraft or cause the tail rotor to hit the ground

Question 8

When you move cyclic angle how does that change blade angle?

Answer 8

Inputs from pilot raise, lower, or tilt the non-rotating swash plate

Question 9

By raising, lowering, or tilting the non-rotating swash plate,

Answer 9

the rotating swash plate is correspondingly raised, lowered, or tilted

Question 10

As the swash plate is moved, the pitch change links that spin with the rotor blades

Answer 10

are also raised or lowered= changing pitch of blades

Question 11

Why does the helicopter run at a constant RPM?

Answer 11

1. increasing rotor speed to get more lift takes too long
2. the rotor blades need centrifugal force to hold them out straight or else the lift forces will fold up and break the blades

Question 12

Main rotor blades are what?

Answer 12

Flexible

Question 13

With no centrifugal force, what happens to main rotor blades?

Answer 13

the rotors will DROOP when they are not spinning

Question 14

What happens to the blades when they are spinning and put under a lift load?

Answer 14

Blades pull up, or “cone”

Question 15

How do you translate aircraft left or right?

Answer 15

Cyclic stick

Question 16

What do tail rotors control?

Answer 16

The direction the helicopter is facing

Question 17

What controls the tail rotors?

Answer 17

Foot pedals called anti-torque pedals

Question 18

The tail rotors also counteract the ______ of the spinning main rotor blade

Answer 18

torque

Question 19

Main rotor spins ______ meaning the fuselage turns _____

Answer 19

counterclockwise
clockwise

Question 20

What does the tail rotor do to keep the aircraft flying straight?

Answer 20

Provides thrust in the opposite direction that the fuselage is trying to turn

Question 21

Moving the foot pedals does what?

Answer 21

Changes the pitch of the tail rotor

Question 22

Tail rotors runs at a _____ RPM

Answer 22

constant

Question 23

More pitch = ?

Answer 23

More thrust
Turns helicopter against the torque force

Question 24

Less pitch = ?

Answer 24

Less thrust
Turns helicopter in the same direction as torque force

Question 25

What if the tail rotor quits?

Answer 25

Helicopter spins around in a circle opposite the direction of the main rotor

Question 26

What does the vertical stablizer do?

Answer 26

Provides the sideways force so tail rotor can have neutral position
Reduces power needed from engine and increases fuel efficiency

Question 27

What does enclosing the Fenestron (tail rotor) do?

Answer 27

Decreasing injuries from tail rotor and reduces strike accidents

Question 28

No tail rotor aircraft

Answer 28

Increases safety and reduces noise. Only works on small aircraft

Question 29

Torque changes as main rotor blade changes, but RPM stays constant, sooooo

Answer 29

A fan with variable pitch blades is put in front of the tail boom to force air into the boom

Question 30

As more main rotor pitch is used, and more anti-torque is needed,
the fan changes pitch

Answer 30

automatically increasing the flow of air out
through the slot in the starboard side of the tail boom.