I will tell you right now that Boeing 737, 757 and 767s are mostly Aluminum and air... the wings are extremely delicate and full of moving parts.
There is noooooo way that an Aluminum plane would disappear into a Steel building like a knife through butter. Planes that have no crash ratings like commercial airliners crash against buildings, not into them.
A Boeing 767 has a maximum cruise speed of 568 miles per hour at 35,000 feet (cruise altitude).
MIT had clocked Flight 175 as going around 580 miles per hour at SEA LEVEL... the Boeing 767s ABSOLUTELY CANNOT GO THIS FAST AT SEA LEVEL.
Cruise missiles travel at around 580 miles per hour at sea level.
Oh yeah, I am getting over a sinus infection and haven't smoked anything in days. I am very clear headed on this.
You are entirely wrong.
The claimed airspeed for that plane is its DESIGNED speed... that is the top speed it was designed to fly safely at.
In a dive at full throttle the plane CAN exceed the speed of sound... but doing so will cause it to break up.
You don't know anything about building, and less about airplanes.
In 1947 a B-25 hit the Empire State building.
The Empire State building is built FAR more robustly than the WTC, with a forest of internal columns and MASONRY walls...
The B-25 was a FAR lighter aircraft traveling at a far lower speed than the 757s that hit WTC.
Nevertheless, the plane disappeared INTO the building.
One of its two engines penetrated to a central elevator shaft and fell down the shaft to hit the elevator car.
The other engine penetrated the ENTIRE building, to come out the far side, and plummet down to crash thru the roof of a Sculptor's studio across the street.
So... history proves that smaller, lighter planes hitting harder structures at slower speeds CAN penetrate.
IN fact, the WTC was little more than a series of columns that the planes hit like an Egg hitting an egg slicer. ( steel columns built to hold that building up versus aluminum structures built for light weight.)
Just to give you an accurate idea of what happened when the planes hit the bulilding, A finite element analysis was done, with an accurate physics simulation model of the plane hitting an accurate physics simulation of the building... and computed on a super computer the way Auto makers simulate crashes in the design phase for a car.
Watch this
http://www.youtube.com/watch?v=cddIgb1nGJ8
It should give you a very vivid idea of what happens when an aluminum airplane hits a 500,000 ton steel cheesegrater.