Great question - XNA to UIO just means Fayetteville Northwest Arkansas Airport to Quito Mariscal Sucr Airport. Now you’ll know what these unique codes when you look for flights! This flight route has multiple associated airports, so we think it might be helpful to learn the name and codes of them as well. They are Guayaquil Jose Joaquin de Olmedo Airport (GYE), Cuenca Airport (CUE), Baltra Airport (GPS), Manta Airport (MEC), San Cristobal Airport (SCY).