Helicopter quiz: Winter 2023

For each item, choose the most appropriate response.

1. A teetering rotor system is characterised by:
   1. two blades joined to a hub which has a single pivot point on top of the mast
   2. blades that are joined to the fixed hub by individual hinges to allow flapping
   3. rigid blades that flex to allow flapping
   4. reliance on centrifugal force to keep them attached
2. An articulated or rigid rotor system is characterised by:
   1. two blades joined to a hub which has a single pivot point on top of the mast
   2. the rotor thrust generating a moment about the CoG to move the helicopter
   3. a moment generated at the hub to move the helicopter
   4. both b & c
3. Teetering rotor helicopters include:
   1. Robinson helicopters
   2. Bell JetRanger and Huey helicopters
   3. Bell 505 helicopters
   4. all of the above
4. The teetering rotor system controls the fuselage attitude by:
   1. tilting the lift vector which then sets up a moment around the CoG
   2. generating a moment at the rotor hub
   3. utilising tail rotor thrust
   4. both a and b
5. Articulated and rigid rotor systems control the fuselage behaviour by:
   1. tilting the lift vector which then sets up a moment around the CoG
   2. generating a moment at the rotor hub
   3. utilising tail rotor thrust
   4. both a and b
6. On a teetering rotor system at low, zero or negative G:
   1. there is increased control power and blade flap is reduced
   2. there is reduced control power and blade flap is increased
   3. there still exists a moment about the hub to control the helicopter
   4. nothing adverse occurs
7. On a teetering rotor system, how does the tail rotor affect fuselage behaviour at low G?
   1. rolls the fuselage, increasing the margin from mast bumping
   2. no effect
   3. rolls the fuselage, reducing the margin from mast bumping
   4. increases the G load, reducing the margin from mast bumping
8. When the teetering rotor flaps excessively and the blade hub strikes the mast, this is called:
   1. droop stop pounding
   2. mast bumping
   3. retreating blade stall
   4. vortex ring state
9. Recovery actions in a teetering helicopter at low G are:
   1. oppose roll with cyclic, then apply aft cyclic
   2. apply aft cyclic to restore G, then correct aircraft attitude once 1G is re-established
   3. push forward on cyclic to unload the rotor disc, then correct roll
   4. lower collective and enter autorotation
10. Mast bumping occurs on which type of rotor system?
    1. semirigid teetering
    2. fully articulated
    3. rigid
    4. all of the above