I read that the probability of being killed on a major airline is about 1 in eight million flights.
If a passenger boarded a flight at random, once a day, everyday, it would be approximately 22,000 years before he or she would be killed.
source:
http://www.planecrashinfo.com/rates.htm
Personally, I'm going to stop flying when I reach my 21,999th birthday, so as not to push my odds