Details:
Apparently there are at least two different things both named aircoin and both trading with the symbol AIR. coinmarketcap is tracking one and cryptocoinrank is tracking the other. One is effectively dead and the other apparently alive as of 12 July 2014. It is not clear which the investigation below describes, nor whether it includes features of both. launched 20 Feb 2014, Aircoin was launched by 'aircoin'