To the answer above, I would like to add that many fear of flying is caused by the fact that when traveling by other means of transport, an imaginary feeling of control of the situation is created, while in flight you are in the womb of a metal bird controlled by 2 pilots at an altitude of 10 thousand meters and absolutely nothing you can do. Although air transport is statistically the safest of all modes of transport.
Most likely, the fear in this case was provoked by the descriptions of plane crashes replicated in the mass media. The information received comes from the senses into the amygdala (this is a nerve center inside the brain), where the information is given a negative coloration. Then the resulting emotion is fixed with the help of newly formed interneuronal connections and some biologically active substances, which makes fear stable.
More information about the structure of the fear system can be found here: https://www.fleming.pro/2016/08/bolezn-nikanora/