After the AIRACS now has become payware, very cheap, but still payware, I wondered do I have to have the latest Airac to get the FMC's to work in PSS Airbus, PMDG 737 etc? If I never fly online and don't care if I have ecxact flightplans for my AI traffic and can live with the fact that there may be a SID/Star for a certain airport which is newer and more accurate, then why do I need (or do I?)the latest AIracs?Falcon

You really wouldn't. :)I use an old 2005 AIRAC set for all my flying, because I have the "complete" set from that period for all my airplanes - SID/STAR & Waypoint/NAV Radio. While realism is important to me, EXACTING REAL WORLD realism isn't so much. Considering online ATC pilots as "professionals", then I am simply an interest enthusiast - I don't need new AIRACs every cycle, but they are fun to use. (Like using old Sectionals you got at the local FBO for peanuts in the sim - they just work!)-Greg

Well, for example a new airport VTBS (Suvarnabhumi Bangkok Intl) opened last month. Assuming you install the new scenery for it, if you want to program your FMS to fly into/from there, possibly including using SIDs or STAR, you either need a new AIRAC or you need to hand edit the new airport and waypoints into your existing navdata. Of course, if you don't install any new or modified field configuration AFCADs, then you won't need any updates.scott s..