I was working on this recently but didn't get much interest from my clan-mates so I thought maybe it would fit better in empires http://www.youtube.com/watch?v=2aYpeBpqVPQ&feature=youtu.be
Pretty impressive for a mapping entity I'd say, but it probably runs like garbage when playing in multiplayer and not on your own local listen server. There are some maps on empires made by this one guy who used mapping entities to make aircraft that flew like helicopters but they really sucked to use. They also felt really dumb and made the whole experience suck. I'm still impressed though, it's just that mapping entities aren't the way to go to put aircraft in the game, know what I'm sayin.
Actually it ran exactly the same when I tested it on my clan's server probably because it uses very little physics I hear what you are saying about gameplay though (not that horrible gameplay ever stopped me making maps)
mcgyver you are starting to become the "disgruntled austrian" archetype. just a notice, no offense. also thats my role, gtfo :D