This sounds like an html question! I haven't tried this, frankly, but seeing how most of the options that goes under helper class methods seem to be html options themselves, you might try this:
<%= select_tag 'airlineinfo', 'smoking', [['Non-Smoking'], ['Smoking'] ], :selected=>'Smoking' %>
Or even better:
<%= select_tag 'airlineinfo', 'smoking', [['Non-Smoking'], ['Smoking'] ], :selected=>airlineinfo.smoking.to_s %>