When picking possible diversion airports along the route, does there need to be ground \ ramp \ firies crew trained for your particular aircraft type at the airport for it to be considered a viable alternative? eg, say the A380 did SYD-PER frequently, but for example there was no A380 trained ground crew at ADL, could you still consider ADL an alternate airport for an emergency diversion if you flew across in an A380?
The company gives us a listing/maps of airports that are categorised as mains, alternates, and emergency.
A main is one that we might be scheduled to fly to...in your example, Adelaide is actually a main. It basically has all of the facilities needed for normal operations, and we carry all of the charts, etc, needed to go there. There won't necessarily be any 380 trained ground crew there, but as long as the refuelling man can connect the hose, we can take care of the rest (assuming there are no aircraft issues).
An alternate is one that we can use if needed for weather diversions and planning. We'll have all of the charts, but it may not necessarily have all that is needed for day to day ops. Going there might entail fairly long delays, but it's certainly quite safe to do so. Battam, about 25 nm from Singapore fits that bill.
A main for a 330 or 767 could well be an emergency or alternate for us...and their emergencies may be unusable to us.
The third category, emergency, is something that we might elect to go to when the poo has really hit the fan. We may not have charts for it, but the runway is adequate. We may not be able to get off the runway after landing on it, but that's not a consideration.