In previous posts is has been mentioned that they are transferable to the heir named in the will of the deceased. You should call AAdvantage Customer Service for instructions. Sorry for your loss.
US or Canada
AAdvantage Customer Service
1-800-421-0600
7:30am - 9:00pm CT, Mon - Fri
7:30am - 7:00pm CT, Sat.
10:30am - 7:00pm CT, Sun
1-817-963-7882 (Fax)