The Boeing 747-400 Before Taxi Procedure says (emphasis mine):
[...]
Flight controls .............................................. Check C
[...]
Hold the nose wheel tiller during rudder check to prevent undesired nose wheel movement.
Move the rudder pedals to full travel in both directions and verify:
- freedom of movement
- that the rudder pedals return to center
- correct flight control movement on the EICAS display
The FCOM (14.20.3 Landing Gear - System Description) further says:
Nose Wheel and Body Gear Steering
Nose wheel and body gear steering is powered by hydraulic system 1.
Primary low speed steering control is provided by a nose wheel steering tiller for each pilot. Limited steering control is available through the rudder pedals. The tillers can turn the nose wheels up to 70 degrees in either direction. A pointer on the tiller assembly shows the tiller position relative to the neutral settings. The rudder pedals can be used to turn the nose wheels up to 7 degrees in either direction. Tiller inputs override rudder pedal inputs.
I wonder how the rudder pedals and the tillers are connected. How can the tiller override the pedal input? I assume the tillers would move when the pedals are used, but do the pedals also move when the tiller is rotated?