Thrust, Lift, Weight (Gravity), and Drag are the forces working on an aircraft.

The thrust isn't delivered through the wheels, so the belt won't increase drag (over the friction constant of the wheel bearings). Airspeed being independent of groundspeed:

I'll say "fly"

BTW, are we talking about an A380



Oh and by the way:

"Cold water does not boil faster than hot water. The rate of heating of a liquid depends on the magnitude of the temperature difference between the liquid and its surroundings (the flame on the stove, for instance). As a result, cold water will be absorbing heat faster while it is still cold; once it gets up to the temperature of hot water, the heating rate slows down and from there it takes just as long to bring it to a boil as the water that was hot to begin with. Because it takes cold water some time to reach the temperature of hot water, cold water clearly takes longer to boil than hot water does. There may be some psychological effect at play; cold water starts boiling sooner than one might expect because of the aforementioned greater heat absorption rate when water is colder.

Who cares about drag and thrust in this example? For that matter, who cares about wheel bearings, conveyor thickness, and every other variable, again in this example? The fact is, is there is zero air flow over the wings so there is no way it can take off. If we are going to disregard this little fact, then I guess what your saying is is that I can pull a red wagon on the belt and if I pull it fast enough, it eventually it will take off?!?! I am starting to feel like the butt of the joke. Im hoping so becasue it would be scarey to think people actually think the airplane would take off. By the way, if we want to rewrite the riddle and add all the assumptions stated above, then I will gladly agree that the airplane will take off... if there is enough lift involved.

You'll overspeed the wheels, but it'll fly.

After careful consideration, I would like to change my answer. My new answer is......There is no way to know if the airplane will take off because we do not have enough information in the original question to make a logical decision. I had to make certain assumptions to definitavely say the airplane would not fly, just as all the folks who said the airplane would fly, had to make certain assumptions. If the "it will fly" guys used my assumptions, they would say the airplane would not fly. And if I made the assumptions that the "it will fly" guys made, then I would say the airplane would fly. Therefore, I capitulate and retract my opinion that the airplane will not fly...BUT...I do not agree the airplane will fly, without getting more information.

no relative wind=no fly, nuff said

The thrust is acting on the surrounding air not through the wheels, the plane WILL move, the wheels will be spinning like of son-of-a-gun but it's going to fly.

I'm going to start asking this on interviews, you guys better find the answer

It could only fly if it was eastbound on a westbound conveyor in the southern hemisphere. Obvious laws of physics here folks.

Hmmm, good point

Only on leap years, when El Nino is in effect.

If your answer is the airplane will fly, you are right...and if you say the airplane will not fly, you are correct also! This question is too vague to answer with any degree of certainty. Need more information.