If by IFR you mean commercial flights then the next largest airport in Alaska is in Fairbanks (international airport with one of the runways almost 12,000 ft), there's also airports in Juneau (longest runway is about 8500 ft) and Kodiak (longest runway is about 7500 ft) that can handle commercial traffic. Obviously none of these have AES and to the best of my knowledge there are no payware offerings for the major airports of Alaska (FS9) which is a shame because it's one of the most beautifull places I've flown in the sim.