Well DXG, DXI, DXN are all available as is XNI and AXI.
Or if you want to get all Canadian, YDX is available. A handful of “Y” airports are in China with the overwhelming majority being Canadian airports of course.
Speaking personally, I’d rather Daxing took DAX as its IATA code best of all —— fine sound, good correspondence with the spelling, easily recognizable
Of course, a survey of current IATA airport codes beginning with D on wiki List of airports by IATA code: D
shows DAX is already occupied by another Chinese airport named Dazhou Heshi Airport in the city of Dazhou
A further look shows Dazhou itself is having under construction a new airport called Baijie Airport, due for completion by the end of 2018 to replace the current one
Presumably, the current IATA code for Dazhou Heshi would get transferred to Baijie once the new airport starts operations, which means it’s unrealistic to put the code DAX and the airport Daxing into what appears to me the aptest match
If we insist on the DA_ code to distinguish Daxing, the outlook for a good match doesn’t improve much either, as almost all nice codes in this category have got allocated, leaving only a very few options available, ie, DAE, DAI, DAJ, DAQ, DAW. None of them looks quite right. Maybe DAW has the best chance of them all if a choice is to be made in this tight category
Then if we check it out on a different set of DX_ codes, the choices are wide and many, as only B, D, E, R are used already (with DXB being the most known), quite the reverse of DA_ codes. Available codes include: DXA, DXC, DXI, DXJ, DXN, DXG, DXP, and so on, among which DXG easily stands out.
Stand-alone, DXG is excellent, but my slight beef with DXG is this: the lineup of airports with G-ended codes looks strong and overcrowded enough: internationally, we got well known HKG, PVG, CDG; domestically in China and lesser known to the outside world, there’s NKG, CKG, KMG
Maybe it’s worth having a bit of variety in coding with Daxing?
Anyway, now that Daxing is the official name, which didn’t come as much of a surprise to the general public, it’ll be interesting to see how close our guesswork here is to Daxing’s official code released by IATA. We’ll find out soon