Apple actually marketed their computers this way once… I don't think they meant it to be funny: https://www.youtube.com/watch?v=LQWjxAdSsHE

Also, on every laptop-like device I've used, there are four things that ever break (well not counting cosmetic damage and five if you count hard drives; I've been lucky with memory). Two of these are display hinges and the display cable. Three integrated displays sounds like asking for trouble. Seperate displays like you suggest might at least make it easier to replace the parts that break. Also you could then use them on a different laptop more easily too.

(The other two things that break for me are the power connection inside the laptop and the power cord where it bends just outside the laptop. I don't think I'm that rough on them...)

Heh, funny you mentioned the IBM laptop. I actually have been thinking of getting one of those (W700ds) and gutting them to be more modern. I like it cause it's IBM (so pretty strong), the second screen is small-ish and not that intrusive, it's easy to take in or out, and it wouldn't take up that much space on a train/plane/wherever.

But yeah, I'm with you that I'd like a mini display that's detachable instead. I think one exists, but horribly overpriced, ugly, and horrible resolution.

This isn't on an airplane but I think it's similar to what you're suggesting: https://youtu.be/6Vjb_LqYOMw