CADH Practice Cards 8 Flashcards
Random questions/statements for exam preparation
Refer to vector diagram
The axis of rotation is represented by the letter …
L
In autorotation, increased density altitude will …
increase rate of descent, increase rotor RPM
To achieve constant lift along the span of a helicopter aerofoil, it may be constructed with …
twist, taper or both
The main function of the reduction drive in transmission of a helicopter is to …
convert high engine RPM to the low RPM required by the rotors
When the pedals are in the neutral position, the tail rotor will have …
a medium positive pitch
Refer to diagram
The vector labelled A is …
descent flow
The diagram is of the autorotative drive region
Neutral static stability is demonstrated when …
a disturbance results in the aircraft settling on a new path
Refer to diagram
The speed represented by the letter Bis the speed for …
best endurance, minimum power, maximum excess power, best rate of climb
In a typical helicopter installation, the main function of the rotor break is to …
stop the rotation of the blades when the engine is being shut down on the ground
The pedal controls on a helicopter …
gives the pilot yaw control
Refer to diagram
The vector labelled F is …
rotor thrust
The diagram is of the autorotative drive region
When a helicopter is in steady level flight at 60kt, the vertical component of TRT equals …
weight, and the horizontal component is TRT equals drag
Dissymmetry of Lift occurs during …
horizontal flight
In a stick fixed hover in still air, lateral dynamic stability is …
weak, but directional dynamic stability is strong
Refer to vector diagram
The plane of rotation is represented by the letter …
F
Flapping is …
angular movemnet about an axis parallel to the chord line
In a still air hover the forces acting on a helicopter are balanced as follows …
total rotor thrust equals weight, torque equals rotor drag
In powered horizontal flight the forces acsting on a helicopter are balanced as follows …
the vertical component of total rotor thrust equals weight, the horizontal component of total rotor thrust equals parasite drag
The blades of a helicopter rotor are usually symmetrical …
True or False?
True
Sweepback on the tips of a helicopter main rotor blade allows …
operation at higher rotor RPM and higher aircraft speeds
In the semi-ridg rotor system, hunting stresses are minimised by …
underslinging the hub
The correct action to recover from Vortex Ring State when height is critical is …
apply forward cyclic
Blade compressibility is likely to be encountered at …
high forward RPM
When flying at a steady speed, the pilot notices a 2-1 vibration, a tendency to pitch up and roll to the left. This would be most likelt to be caused by …
retreating blade stall
A heavy 2 engine helicopter with a TAZ of 150 kt at A100 has a certain turn radius at 20° angle of bank.
The turn radius of a light single engine helicopter at the same angle of bank, speed and altitude would be …
the same
Transveres flow (inflow roll) effect is most pronounced at …
10-20 kt
The conditions required for retreating blade stall are …
high forward speed, high angle of attack, low rotor RPM
The effect humidity has on density altitude is …
density altitude increases with increased humidity
When a 60° level, banked turn, the apparent weight of a helicopter will be …
twice as much as in level flight
Compared to a standard rate turn, a high rate turn would result in …
a higher disc loading and higher rotor thrust requirement
In the conventional helicopter compressibility is indicated by …
lateral vibration, nose pitch down, roll right
Refer to diagram
The speed represented by the letter C is the speed for …
best range
The height of the ground cushion is approximately …
one rotor radius
In a stabilised autorotation flight you notice that RRPM is high. You would also expect …
the rate of descent to be abnormally high
Refer to blade diagram
The position on the rotor blade which provides the greatest amount of autorotative force is …
C
When a helicopter is in sideways flight, the position where the angle of attack will be greatest is …
12 o’clock or forward of the aircraft
Exceeding forward airspeed limits in a helicopter can result in supersonic airflow first occurring …
at the tips of the advancing blade
The device which automatically disengages the engine from the rotor system in the event of engine failure is the …
freewheeling unit
