Hi, neighbor! (Work in Elgin, live in Algonquin!) :D I've taken knitting needles on Southwest out of Midway and never had any trouble, and Amy (Website Goddess) came out here with a bag full of needles and knitting and had no trouble - FWIW. Both times on Southwest, but I think it's the airport, not the airlines, that decide it. I might be wrong...
Best wishes to your father and your family!