Hetfield ,so if you are doing a cat3, how do you get the ILs dme up if the bus has decided not to show you on the pfd?With the Smiths fms you could cdu tune it to display it on the rmi,but this is not possible with the honeywell as it only allows vor's on the prog page to be remote tuned.
Also there are a few non-precision approaches that use the ils dme for step down fixes( Manchester springs to mind).Again what do you do if the dme does not display on the pfd.Do you store the dme as a new navaid and will it display it??