I have no problems flying (in) an airplane, looking outside from tall buildings, etc.
I'm quite uneasy when standing next to low balcony barrier, or on the edge of a cliff.
I'm even more uneasy if I can see my feet without any support underneath, such as if I'm strapped into paraglide or swing carousel. I'll hold on really tight even though I know I'm securely strapped in and can't fall out.
Strangely I don't have any problems with glass floors.
I haven't tried parachuting yet, so I'm not sure how would I react
I rode in a hot air balloon once and I was fine - the basket was tall enough