CADH Practice Cards 2

Question 1

Raising the collective, collectively changes the pitch….

Answer 1

an equal amount relative to the rotor hub

Question 2

The load factor for a 60 degree angle of bank is…

Answer 2

2.0 (twice the weight)

Question 3

One major issue to consider when flying at a high AUW is…

Answer 3

if an engine failure were to occur there may not be enough collective available for a safe termination on the ground

Question 4

Transverse flow causes a conventional helicopter to …

Answer 4

roll to the right (inflow roll)

Question 5

Winds from the 9 o’clock position can produce…

Answer 5

tail rotor vortex ring state

Question 6

Bernoulli’s theorem states …

Answer 6

that total pressure is comprised of static and dynamic pressure and total pressure will remain constant unless energy is added.

Question 7

A semi-rigid rotor system has freedom to….

Answer 7

feather and flap

Question 8

One of the reasons for using symmetrical aerofoils over asymmetrical aerofoils is…

Answer 8

Limited movement of the centre of pressure (C of P)

Question 9

Increasing headwind will effect your endurance?
True or False

Answer 9

False. wind does not effect the endurance of a helicopter

Question 10

Tail rotors use approximately _% of engine power?

Answer 10

10%

Question 11

Delta 3 hinges are employed in tail rotor design to minimise…

Answer 11

flapping angles

Question 12

Forces that will increase the coning angle of a rotor disc are…

Answer 12

a decrease in the centrifugal force (RRPM) or an increase in the total rotor thrust (TRT)

Question 13

Tail rotor roll in a conventional helicopter is compensated for by….

Answer 13

offsetting the mast to the left

Question 14

The hover height at which ground effect becomes negligible is…

Answer 14

one rotor disc diameter.

Question 15

A high frequency buzz is most likely coming from…

Answer 15

an out of balance tail rotor

Question 16

Blade taper is…..

Answer 16

a reduction in surface area from the root to the tip

Question 17

A scenario that is most likely to give you mast bumping is….

Answer 17

a low to negative G light manoeuvre

Ref: Principles of Helicopter Flight, Chapter 19, pg. 167

Question 18

The vector that replaces induced flow during autorotation is…

Answer 18

descent flow.

Question 19

You are departing from a HLS beside a large solid object, you should consider….

Answer 19

Avoid hovering beside the object as much as possible.

Question 20

Autorotation’s with high AUW and high density altitudes can cause…

Answer 20

high rotor RPM

Question 21

A conventional helicopter is hovering with a strong crosswind coming from the right. If loss of tail rotor effectiveness (LTE) were experienced, it would be most likely caused by …

Answer 21

a low tail rotor angle of attack and high tail rotor induced flow

Part 61 MOS Schedule 3 Unit 1.3.3 CADH 2.2.3 LTE

Question 22

Refer to the Vector Diagram Below.
The diagram represents the forces and airflow on a section of rotor blade during a steady hover in nil wind.
Vector G represents the …

Answer 22

induced flow

Part 61 MOS Schedule 3 Unit 1.3.3 CADH 2.2.1 Label Vector Diagram for Hovering Flight

Question 23

The flapping action of a fully articulated main rotor system in sideways flight causes the advancing blade to …

Answer 23

rise and accelerate

Part 61 MOS scedule 3 Unit 1.3.3 CADH 2.3.1 Flapping

Question 24

The reason why main rotor blades of most helicopters are symmetrical is to provide for the …

Answer 24

limited movement of the centre of pressure throughout all phases of flight

Part 61 MOS Scedule 3 Unit 1.3.3 CADH 2.1.1 Aerodynamic Properties of a Rotor Blade - Shape

Question 25

The total reaction force is defined as …

Answer 25

the resultant of the pressure forces acting on an aerofoil

Part 61 MOS Scedule 3 Unit 1.3.1 CADC 2.2.1 Bernoulli’s Theorem

Question 26

Drag is defined as …

Answer 26

the component of total reaction acting parallel to the relative airflow

Part 61 MOS Scedule 3 Unit 1.3.1 CADC 2.2.1 Bernoulli’s Theorem

Question 27

The component of total reaction acting in the plane of rotation opposite to torque is called …

Answer 27

rotor drag

Part 61 MOS scedule 3 Unit 1.3.3 CADH 2.1.2 Rotor Drag

Question 28

The component of total reaction acting parallel to the relative airflow is called …

Answer 28

drag

Part 61 MOS scedule 3 Unit 1.3.1 CADC 2.4.1 General Helicopter Aerodynamics - Drag

Question 29

The helicopter is autorotating in nil wind at the airspeed recomended for maximum range, with rotor RPM at the bottom of the green arc. If you maintain the same airspeed, lowering the collective will …

Answer 29

reduce endurance

Part 61 MOS Schedule 3 Unit 1.3.3 CADH 2.6.1 Effect on Autorotative Flight on Variations in RRPM

Question 30

The most likley time that LTE would be experienced is …

Answer 30

low airspeed manoeuvers with high main rotor pitch

Part 61 MOS Schedule 3 Unit 1.3.3 CADH 2.2.3 LTE