My understanding is that planes don't fly directly upside down, and they angle the wing slightly to make a kinda-sorta-airfoil.
How helicopters can turn directly upside down, and fly that way[1], without reversing the direction of their props, that I don't get. (Thinking about it now, I think it turns from a helicopter to a hovercraft? Eg, this is a ground effect?)
Jesus H. Christ, that brings back memories. When I was (much) younger, probably somewhere between 9-13 or thereabouts, I had a brief phase when I really in to "weird stuff." I spent a lot of time reading books about UFO's, ghosts, the Bermuda Triangle, the Philadelphia Experiment, "ancient aliens", the "Oak Island money pit", blah, etc. etc. And the whole Flight 401 thing either figured very prominently in at least one book I read, or it kept re-appearing or both, because I just recalled a whole bunch of profound feelings associated with that story. I remember being really freaked out by it at the time. Enough so that I probably wouldn't have wanted to get on an airplane had I had any reason to fly back then (I didn't).
I'd like to say that even back then I mostly didn't really believe all that stuff, but I think maybe I kinda did, at least to a degree. Now I think it's all bollocks, and maybe that's one of the things I miss about being a kid... that sense of fascination with the mysterious and unknown and the sense of possibility that comes with allowing yourself to believe in the Bermuda Triangle, ghosts, yadda yadda.
I'm with you on the last one, and I sometimes wonder whether religious people still have that sense of fascination with the unknown, or with what is possible.
I would like to have that again, if only for a few moments.
Lost souls on Boeing planes isn't too far fetched. Lord Xenu flew in all those thetans on rocket powered DC-8's which were originally made by McDonnell Douglas who merged with Boeing. Basically Snakes on a Plane but with souls and Tom Cruise.
An accidental time traveler traveling slightly out of alignment with their timeline would likely manifest as something we would describe as a ghost, for a brief moment.