Sam Spade wrote:

So far as I know, although a lot of them used (and still do with the
older birds) DME/DME updating, none of them used VOR/DME updating...well
unless that was all that the system could see...and often it would just
stay with IRU position rather than use a bad solution.


Yes, airline FMSs are capable of VOR/DME and DME/DME updating, but you are correct that these
modes don't get used much with GPS equipage.

Mike