From an engineer's viewpoint, the holes in the Twin Towers appear to be more the work of manual labor and a touch of dynamite than plane impacts.
The best images on the holes can be seen at the German Engineers' website (their viewpoint, too). http://home.debitel.net/user/andreas.bunkahle/defaulte.htm
Most all columns are straight and undeformed. If an aircraft had struck the exterior, the weakest components would begin deforming and absorbing the kinetic energy. The expected progress would be from the plastic "radome" and then fuselage as it progresses forward. There would be an attrition of recessed Tower windows, but the plane had to contend with columns and spandrel plates to enter the building. The estimated speed varies for flight 175, from 300+ miles and hour to in excess of 500 miles per hour, close to the crafts maximum velocity (speed varies depending on which video calculations are made from (shouldn't it be the same?)). As the front compresses at x00mph, a shock wave would travel backwards the length of the craft at a rate many times greater. Wings, tail and fuselage sections might shear off/buckle well before their impact. The destruction would continue on the aircraft until such point, it present a stronger structure than the wall, this being when nose landing gear encounters the compressed wreckage in front of it. Depending on it's locaton to columns, windows, plates, it is conceivable, localized damage to the building may commence. As forces are applied to the walls from the craft, bending would occur in the "elastic" range. The next serious threats to the wall would be the massive jet engines, being the greatest concentrated masses on the airship. Landing gears in the wings would also impose some significant localized forces. The wings would spread out their load over 200 feet of wall; the localized damage to the structural wall would be negligible from wing structures.
The expected failure mechansim for the walls would be some bending of vertical columns, some buckling of the square cross section, and some stretching of bolted plates, possibly sheared bolts/ripped holes. Considering the columns were reinforced horizontally every 12 feet with an acre of concrete and steel floor, bending of columns would be limited, and the square cross section would buckle, flattening out with a marked increase in width. Some buckling of floors could occur, allowing bending of vertical columns in the plastic range, with permanent deflection. The net result of a jetliner impact should produce at most, a slight pocket similar to a baseball glove, with 3 dents.
What would explain the holes captured on film? One very plausible scenario is that a team of workers jackhammered/torched out sections of flooring; removed the nuts and bolts interlocking the 3 columns sections; torched numerous columns to the outline of plane fuselage & wings (with no rudder); introduced explosives at the outside of the columns (within the siding). The white explosions on the south, east and north walls (white explosions, not black jet fuel fires which show up frames later) launched aluminum siding panels hundreds of feet horizontally, with many still attached dangling down. The walls caved inwards revealing the handiwork of the demolition crew.
One estimate (overestimate?) is 2/3 of the columns are cut. If 1/3 are not severed, there should be airplane wings jammed onto the outside of the building or laying on the ground. There was no plane debris seen in the opening nor on the ground. There was also no damage to the building siding where the rudder should have struck.
Go read many of the articles posted by the German Engineers, on "pixel planes," zoomed out "explosive" oversized fireballs, video enhanced debris showers, Pentagon, Shanksville, World Trade Center 6 & 7, etc.
MIT, 30 pieces of silver is the price for corrupt reports these days?
If anyone cares to discuss the science and evidence of 911, I'll be happy to correspond via Personal Message.