The ATC uses the Captain's selected ADC if the ATC is in "L" and the F/O's selected ADC if in "R". Look at the instrument source select switches outboard of the CRT's(or LCD's as applicable).
Our 767's can't be the same as your 767's. We use both Left and Right ADC's (with inputs from the instrument source switches as per the 744)
Last edited by NSEU; 31st Aug 2008 at 23:46.