Hi, 'The Rage',
On a B747 Classic, where this body gear steering system was developed, the system is much more manual (thank goodness!).
The same input from the NLG steering tiller is used, but the Capt/FE can disable the system by a simple switch selection when required.
Just prior to starting the takeoff roll, the FE disables the Body Gear Steering when the acft is lined up, ready. If the BGS is not properly aligned, it will do so then, and remain there until the switch is again selected 'On' at the slower end of the landing roll, unless the Capt takes a high speed runway exit taxiway, at which time the FE turns it on when the acft is slowed to taxi speed.
Operating in icing conditions, when taxiways/runways are very slippery, the acft can start a slide when a turn is initiated by the Capt, so the BGS is usually left turned OFF during these times.
The acft can be despatched with the BGS inoperative, but larger radius taxi turns are required.
Another reason why the Classics are better!
(It's just a real pity they are getting old and unreliable these days)
Hope this helps,
Cheers
