Following Nuttys mention of heights, I experienced the 'need to pee' feeling when sitting on the floor of the Varsity, feet dangling in space, looking through the bomb aimers windows at the ground 4,000 feet below.
Similar sort of view if you were waiting to parachute. OTOH getting into the belly and lying down was no problem.
On fear of flying, either ignorance or overconfidence but not fear. OTOH certainly anxiety. I still recall one anxiety nightmare. The setting was a limited procedure radar bomb run using LP3A on a southerly heading and confusing left and right.