CADH Practice Cards 1

Question 1

The helicopter you are flying has a fully articulated rotor system, on approach you notice a vibration coming from your main rotor. Upon landing it becomes so aggressive you need to abort, you have experienced ……

Answer 1

Ground Resonance

Question 2

Blade twist can be incorporated into rotor blade design…..

Answer 2

to reduce lift towards the tips of the blade

Question 3

An increase in gross weight effects the power required curve by…..

Answer 3

causing it to move up and to the right

Ref: Principals of Helicopter Flight, Chapter 13 pg.107

Question 4

The advantage of shutting down your helicopter with the wind coming from the 3 o’clock position….

Answer 4

will avoid your main rotor contacting the tail boom

Question 5

Fully articulated rotor systems have the ability to…..

Answer 5

feather, flap and drag (lead/lag).

Question 6

During take off outside the hanger in a max TOW helicopter, your power demand is increasing and your need to use aft cyclic. You are experiencing…..

Answer 6

Recirculation.

Question 7

Induced flow is….

Answer 7

undesirable

Ref: Principals of Helicopter flight, chaper 6.

Question 8

Flap back is a phenomenon experienced in accelerated flight. It will cause…..

Answer 8

the nose of the helicopter to pitch up

Ref: Principals of Helicopter Flight, chapter 12, pg. 94

Question 9

Hovering IGE (HIGE) is only useful when the helicopter is within….

Answer 9

one rotor radius of the groud meaused from the rotor hub

Question 10

Vortex ring state (VRS) is likely to occur duiring a…

Answer 10

high rate of desent with slow forward moving airspeed such as a vertical approach at high power into a hollow surrounded by trees

Ref: Principals of Helicopter Flight, Chapter 19, pg. 157

Question 11

During IGE, the rotor tip vortex are….

Answer 11

reduced.

Question 12

During a slope landing with left skid on the ground, you lower the collective and hear a noise from the main rotor hub. You have just experienced….

Answer 12

Mast bumping

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

Question 13

IGE, the air pressure or density is increased, which acts to….

Answer 13

decrease the downward velocity of air

Question 14

Effective Translational Lift is experienced with…

Answer 14

wind or forward airspeed between 10-12kts

Question 15

Gyroscopic Precession is when…

Answer 15

any force applied to a rotating disc is felt 90d in the direction of rotation.

Question 16

In a stick fixed condition, in forward flight, a helicopter experiences….

Answer 16

static and dynamic stability in the yawing plane.

Ref:

Question 17

Tail rotor drift is compensated for by….

Answer 17

tilting the mast to the left (for rotors spinning anit-clockwise) and to the right (for rotors spinning clockwise)

Question 18

The corrective actions for loss of tail rotor effectiveness (LTE) is to….

Answer 18

simultaneously lower your collective (if height permits), push forward on the cyclic and apply left peddle to counteract yaw.

Question 19

When a conventional helicopter experiences Effective Translational Lift the nose of the helicopter will…

Answer 19

yaw left.

Ref: Principales of Helicopter Flight, Chapter 12, pg.99

Question 20

During autorotation, if the cyclic is moved aft, rotor RPM will…

Answer 20

increase, then return back to its original RRPM

Question 21

Rotorcraft VNE is a term usually related to …

Answer 21

retreating blade stall, it is expressed as a IAS and it decreases with increased pressure altitude or increased ambient temperature

Question 22

Overpitching could be rectified by …

Answer 22

Lowering collective and opening throttle

Question 23

An autorotative flare before landing is desirable to …

Answer 23

decrease rate of descent and forward airspeed

Question 24

When the cyclic stick is moved forward in a helicopter with no advance angle you would expect the swash plate to …

Answer 24

tilt right

Question 25

A helicopter in forward flight is …

Answer 25

dynamically stable and statically stable in the yawing plane only

Question 26

The Centre of Pressure of an aerofoil is …

Answer 26

a point along the chord line of an aerofoil through which the resultant or total reaction of all aerodynamic forces is said to act

Question 27

In autorotation the rotor exerts friction on the transmission tending to …

Answer 27

yaw the aircraft left

Question 28

With a delta three hinge, the flapping hinge is set at an angle so that …

Answer 28

when the blade flaps the pitch angle is altered

Question 29

Over pitching is caused by …

Answer 29

increasing collective to the extent that engine power cannot overcome rotor drag

Question 30

An aerofoil produces lift by …

Answer 30

deflecting the airflow and causing an increase in velocity of the air flowing over the top surface