As a Pax, G/A due to "hot and high" apc
As a J/S, G/A due to "unsecure cabin"
As an ATCer "sudden squall" ...a/c in the flare
"lower than minimums"
"crosswind"
"departing a/c vortex"
"pax in the loo"
"no nose wheel"
[landed ok later]
I could go on, but I think you get the point. The reasons are as many and varied as th a/c types
watp.iktch