Originally Posted by
DanTravels
Better tell that to IATA, 'cos they sure think there is. Along with other metropolitan area codes that don't correspond to specific airports. Like, oh, say, NYC, CHI, WAS, LON, PAR, BER, ROM, MOW, TYO...

Before I posted I checked ExpertFlyer and none was listed.
Ok .. aa.com allows RIO for all of the two airports there, but since AA only serves one it is kinda a mute point.