I can only speak about Asia.
We NEVER turn off the XPDR or the TCAS in our CX 777's ( unless the NNC requires it to TA only )
-The modes
S knows it's on the ground and wont trigger a TA/RA in another nearby A/C.
-now days we can NEVER see other A/C on the ground on our ND, even if they have their XPDR switched on. Since they modified the system I have NEVER seen another A/C TCAS target on the ground. ( We used to get the occasional TA from a parked A/C.)
-However you CAN see the airborne A/C coming and going.
They modified the system logic about 3 years or more ago, or was it when they introduced mode S? Not sure but it works fine.
