I lost two friends when I was a student, many years ago - one in a rock climbing accident, another in a freak incident involving a gas leak.
Two relatives died at a young age of different types of cancer.
When I was on holiday, a chap dived into a lake and hit the bottom - he was lucky, he survived with nothing but very bad bruising.
On a proposed camel trek (it was abandoned due to poor organisation) two people fell off and were seriously injured.
Several friends have been injured in car accidents.
And yes, I do have two acquaintances who were killed in an aircraft accident too.
And I know several people who've died in their beds of natural causes.
One thing is certain - life is invariably fatal...eventually!!!! What's so special about flying? I ride horses too, and that's much more dangerous; ask any insurance company. But no-one seems to get upset about that, only the helicopter flying.
So no, I don't worry. But since I know I'm not immortal, I try to keep my will up to date and make provision for my nearest and dearest. Just like everyone else.