The Scientific Approach
Here's a Truther who decided to test what happens when a 767 flies into a 110-story building. Of course, he didn't have a 767 or a 110-story building, so he improvised:
I set up an experiment testing how a plane might break up upon impacting arrayed steel columns like the WTC wall. The plane and the columns were both constructed of similar pieces of wood (which here favors the plane, since in real life, aluminum is weaker than steel). The dimensions of the models were not perfect, but they were a rough match for the WTC and a 767. I did not put floors into the model, so this also favors the plane.
I pushed the plane forcefully into the "wall", and while the fuselage penetrated the wall after reasonably strong force was applied, the wings broke off at the root where the wings met the plane. The wings actually bent backwards and slid into the hole alongside the fuselage. The wood of the wings actually broke. A few "columns" broke where the fuselage went in, and a couple broke on either side of the fuselage hole, where the wings broke off-- but basically the array of columns were much stronger than the long wings.
Well, I mean, that proves it. But our intrepid researcher was not satisfied and so he decided to try even stronger wings:
The wings did not break, but I COULD NOT RAM THE PLANE THROUGH THE WALL of columns, even using all my strength. Only after repeated ramming attempts was I able to get the plane inside, and even then it went in sort of sideways, without the wings breaking any extra columns.
Sadly, the experimenter did not include photos of his efforts. But this gentleman has proven beyond a shadow of a doubt that the holes in the World Trade Center were not made by an airplane.
Hat Tip: Instapinch
Update: Be sure to read of Chad's own attempt to replicate 9-11 in the comments. Great comment!