First off, I'm not discouraging you. Inquisitiveness is the first step to becoming good at this stuff. And it does seem like a really neat wing configuration (especially if you watched a little too much Star Wars) [img]i/expressions/face-icon-small-smile.gif[/img] . BUT:

Such an aircraft would be EXTREMELY aerodynamically and structurally inefficient.

Just look at the top half of the X for now. Viewing the aircraft from the front or the back, you see one right and one left wing, just as on a standard aircraft, but with a 45 degree angle between each wing and the horizontal. This angle is called dihedral. Most manufacturers of light aircraft include some degree of dihedral, but it's usually on the order of 3 or 4 degrees. Visualize the lift pointing out the bottom of each wing (really simplifying the matter, but that's the point). Each wing will generally develop the same amount of lift, which can be mentally split between a horizontal and vertical component.

If the aircraft is banked, the low wing approaches horizontal, and the high wing gets further from it. Keeping it simple, the low wing's lift now points more vertically, which causes that wing to rise, making the plane return to straight and level flight. Thus, the manufacturer is accepting a little loss of lift (because in straight and level flight, there's still some horizontal component of lift from each wing) to gain stability. Generally, since lift is lost, dihedral is added only until the aircraft's stability goals are met.

If the wings of the aircraft angle down below the horizon (as on an F-104), that's called anhedral, and has the opposite effect (if you visualize the lift again, you'll see why). That's done on fighters to enhance maneuverability. But it also involves some loss of lift. However, the benefits outweigh the problems for that particular application.

What you're suggesting puts the lift from each wing equally up and to the side. The dihedral of the top half of the wing assembly is effectively canceled by the anhedral of the bottom half, so you gain neither the stability of dihedral nor the maneuverability of anhedral, and lose an IMMENSE amount of lift.

In order to reclaim that lift at a particular speed, you can either increase the total wing area (which increases drag), change to a higher-lift wing section (which increases drag), or fly the aircraft more nose-high (which increases drag).

Finally, the wings still need to lift the airplane. But only about 70% or so of the total lift generated by the wings goes to lifting the airplane (that's trig on the 45 degrees). So the TOTAL force generated by the wings has to be 41% greater than with a conventional design. The wings correspondingly have to be built strongly enough to resist ALL of the force that they generate. And strength = weight. And weight = bad.

Keep thinking, keep dreaming, and keep brainstorming. You might even still feel like making this thing, just for the sake of making it and having something completely different. But it has little practical application.