You don't have to be an expert in the aircraft industry to know when something looks un-flyable (<< ?? Is that a word ?)
Any kid that threw a paper airplane has a gut feeling about things that can fly in air. A lot of spacecraft we see in scifi look like they would have little maneuverability and be very aerodynamically unstable yet scifi writers, production artists, directors INSIST on flying these things in Earth atmosphere etc


Here are my top 5 bellyflopper

5
"Thunderbolt Star Fury" based on the original Babylon-5 Starfury, JMS did great with the originals, they looked great and he kept them in space but for some reason he insisted on using the new in "Crusade" one to fly missions or leisurely trips on planets

4
"Battlestar Vipers" with tiny little wings I can't see how these things would fly. The new Cylon ships look like the would fall out of the sky also

3
UFO ships in "ID4" Independence Day, considering how vulnerable these things were to some windows bug I'm sure the flight control software was a disaster

2
Star Wars "X-wing", Boba Fett ship etc Most of these ships look like they would drop out of the sky. The Falcon still looks great though

1
A the winner is our "StarTrek Shuttlepods". Built like a brick I've never understood how these things fly, I suppose they have some tractor beam, anti-grav technobabble to overcome that stuff. Apparently it can fly at Mach 8 but it still looks like it would fall like a rock