A previous bad experience
Some people can develop a phobia of flying due to going through a bad flying experience in the past.
You are claustrophobic
People who are claustrophobic (have a fear of closed places) might feel uneasy when they board a plane due its being tight and small.
You experience panic attacks
Some people who have a fear of flying get panic attacks when they get on a plane, which makes the experience even worse for them.
Hearing about bad events
People who hear about bad events in the media such as plane crashes and airplanes going missing generates fear in them and makes them not want to get on an airplane again.
Due to September 11
Some people began to fear flying after the September 11 terrorist attack that involved a plane crashing into a building.
You like being in control
Some people fear flying as they no longer have control over their lives when they are in the air.
Events unrelated to flying
In some cases, people develop a fear of flying when they board a plane right after going through a bad experience than is unrelated to flying such as losing a job or being assaulted. In this case, their fear of flying is induced by external factors.
Fear of heights
Some people develop a fear of flying as they originally have a fear of heights (acrophobia). (See Why Am I Afraid of Heights? Are you Acrophobic?)
Fear of motion sickness
Some people dislike experiencing motion sickness and having to vomit on the plane, which makes for an unpleasant situation.
Fear of hijacking
Some people are afraid of flying as they have a fear of the plane being hijacked and being subjected to danger.
Losing someone close in a plane crash
If a person previously lost a close person or family member in a plane crash, they may develop a fear of flying as a result.
Due to the depiction of plane crashes in movies
Hollywood has been producing movies about plane crashes for a long time, which can make a person develop a fear of flying. (See What a plane crash feels like?)
Fear of losing control
People who fear to lose control might develop the fear of flying. In such a case the person not be able to unconsciously accept the idea that someone else is driving the plane they are on.
Why am I afraid of flying?
Flying phobia? Why you shouldn’t be scared of flying? This is why you’re afraid of flying—and how to get over it