Wings Break Off
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.
This actually makes sense in terms of physics. The fuselage had a concentrated impact force on a relatively small front area, and thus could break the columns inward. However, a wing has a much wider impact area, which dissipates the impact force, thus favoring the columns' strength. If I were an engineer, I'm sure I could find an equation that could describe this phenomenon. Basically, of course, it is the same principle why a pointed object has more penetrating power than a long straight edge-- even if both are equally sharp.
Note that in real-life, the aluminum wings should break off even more readily when they impact heavy steel columns than in this experiment.
This finding that the wings break off also fits with what is observed in other plane crashes: the wings break off.
This means of course, that no 767 hit either WTC tower.
The plane-shaped hole was merely a ruse, to trick people into thinking a large plane had impacted the WTC. Unfortunately this trick defied physics.
Further: in theory, wings could break through the columns if they had enough mass and momentum. The key point though is that on a plane, the wings are far from the center of mass, they cannot carry enough force to break through the columns and thus their response is to break and fold back. The analogy would be like having your arms stretched straight out and trying to knock down two strong wooden posts on either side of you with your fists. With your whole body behind your hands, you could knock down one post, but your body's force is too diffuse to knock down both posts when your arms are stretched out to the side.
And yes, Holmgren was right. If the wings and plane were strong to slice cleanly into the wall, the plane should have sliced all the way through the building!
This piece from Holmgren is worth a re-read.