Asking for A320 NWS system
 

hello! i am training on A320 CFM engine.
A320 NWS(nose wheel steering) system make me confused.
refer to A320 CBT and some tech books mention NWS is powered by Green on 320,
but powered by Yellow on 318.
however, refer to FCOM and QRH, All 320 family is powered by Yellow.
and 320 system questionary has both answers (1 Q with G and 1 Q with Y).
have asked some friends who flyin 320 already...
some said on G above priority valve, others said on Y below priority valve.
is there anyone can explain this.

Originally the NWS was on the G system and that will be reflected in the CBT course. At a later date, Airbus used the Y system for NWS.

The easiest way to find which you have, is to use the QRH for your MSN and look at Ops Data, HYD Architecture.

so old system was on G but new is on Y as my FCOM and QRH.
Thank you.

Till MSN 1938 NWS was on Green hydraulic. From MSN 1939 it is on Yellow system.

The change in Hyd systems from G to Y allows the NWS to remain fully functional if Gravity GeAr Extension is used. On older a/ c the NWS hydraulics are routed through the NW gear door circuit .:ok:

We still have the NWS on green system at MSN 2000+.