Related Clues:
- Moving arm up and down
- Up and down, round and round it goes
- It's essential to a helicopter going up and down
- It spins or turns to right
- Reversible mechanical component
- Revolving part of turbine
- Part of engine that revolves
- Revolving blade
- Revolving blade (as on helicopter)
- Revolving arm
- It goes round
- Revolving arm in machine
- Turning blade
- Revolving mechanism
- Revolving part of machinery