If I might offer the perspective of another avoidant passenger I think sometimes it isn't even about being up in the air.
It's more the sheer scale of the modern airliners and the number of folks you're surrounded by, the procedures, the sort of hidden stuff behind the shiny surface and gleaming smiles - stuff you aren't party to as an SLF, because it might freak you out I suppose - but the feeling that other people are totally in control of the situation, and you're not (for obvious reasons) can maybe be a trigger for a lot of people's fear.
I think it's part of mine. I've only flown twice - once there, and once back because I had to. I spent the week obsessively watching the weather forecast. Don't get me wrong, I adore aeroplanes and find them incredible to watch, in fact I'd pay extra to live under a flight path.
But going in a large one again is something I'd never do. Maybe it is my way of feeling in control in a big world, but it's just the way I am and luckily I don't have to travel. You know, sometimes a smaller, more bumpy plane is easier than something that doesn't even feel like it's moving - like you're not quite in touch with your surroundings, somehow - I know I'd far rather go in a tiny little turbo prop than an A380.
As a slightly feckless motorcyclist for many years though I wonder if there's a parallel in the way a lot of folk hate going pillion, but are happy to ride the beast themselves. Control, again, I suppose.
There's also the claustrophobia aspect which must affect a lot of folk. The 'not being able to get off if I want to' thing. That is probably the strongest thing for me. You can get off a boat, usually, somehow.
Thinking about it...how do planes stay up anyway?
