When I fly GA aircraft with GPS, I'm able to find the various radio frequencies for ATIS, ILS etc...with no problem. Yet when flying heavies, even the good payware addons, there isn't any way to get these frequencies within the FMC. Am I missing something?Curt

Well, you're required to have all the appropriate charts and plates on your person in a heavy, and since your route is scheduled, you pretty much know beforehand what airport data you need. I have all the paper charts myself, but that cost me a lot of money. Prior to buying them all, I would plan my route, then write down all the ATIS and ILS data for my arrival airport so I was prepared. Also, some add-on heavies that include a realistic FMC will give you the ILS frequency and sometimes the runway heading on your REF INIT page once you select the runway you're given for landing by using the DEP/APP page. It will show on the page where you enter your flap/speed info (REF INIT) or on a NAV/RAD page.

It depends upon the way the addon aircraft FMC is built - but no - most of them do not read the airport data in FS2004 - only displaying data from their own external database.Those data pages are part of the native FS2004 programming of the GPS gauge. So if the addon doesn't have a way for you to bring up the default GPS - you can't get that data in that format.