The Des Moines Airport Authority will take public comments on a study of two potential sites for a new airport terminal from 5:30 to 7 p.m. Sept. 13 at the Des Moines Central Library downtown. Consultants will outline the sites, one near the present terminal and the other on the southern part of the airport grounds. The airport board’s discussion has leaned toward building just northwest of the present terminal. Airport officials will make a final decision after collecting comments from the public.