Here is from a friend of mine who works in the field`
"First off there is footage of the commercial airliner hitting the building.
I've seen it you can prob find it on the internet quite easily.
The pentagon was made to take violent impacts sort of like how a kevlar vest works. It lets some in and absorbs the impact bit by bit.
The streetlights going away from the pentagon.
Concussion waves. Any large explosion has them; hell you can even feel them when a military fighter takes off in burner.
Why weren’t there parts?
Like it was said above aircraft are made to be light but strong.
A.K.A. they use a lot of magnesium, beryllium, aluminum, with some titanium for structural support.
Every metal except for the last listed melts fairly easily.
Jet fuel from an engine fire can melt titanium easily though.
I saw this from an F-15 aircraft 73-110 which had an engine fire and when it landed the titanium engine panels were running off the jet like syrup.
Why wasn’t more debris found?
This depends on the impact and how much fuel load the aircraft has left in it. Meeting the pentagons reinforced walls was one hell of an impact and it was heavily loaded down with fuel.
For example I was on a team that had to locate and investigate a crashed F-16 in New Mexico.
The entire aircraft was in a 6 foot diameter hole about 5 feet deep.
What was left of that aircraft could easily fit in the trunk of my mustang.
Engine parts.
Engines are not made of massive parts but of a whole crap load of small parts and very flimsy fan blades that spin at insane rpm's and disintegrate at the drop of a hat.
Which is why in the military we do a F.O.D. Foreign object damage walk every morning to pick up any rocks and such we can find on the flight line.
Just one large screw on the runway during takeoff roll can cripple an engine and cause the aircraft to crash.
Boeing, Prat Whitney, Northrop, and GE make most of today’s military and commercial engines.
If a Boeing or GE engine takes a hit its toast because the operation specifications are extremely close.
It gives them more thrust and better operating ability but if anything odd occurs watch out.
From a GE rep I was talking to GE engines are more fun but a Prat Whitney engine will get you home.
My squadron uses Prat Whitneys. 100's were upgrading to 220's soon wo hoo.
But what Do I know I’ve just been working on Military aircraft for the past ten years"
Also from another friend of mine
"Aluminum- Melt point 1220°F (source: periodic table of elements)
Titanium- Melt point 3034°F (source: periodic table of elements)
Jp4- Freeburn temperature 9752°F (source: Volume 1, The Dynamics and Thermodynamics of Compressible Fluid Flow)
Now. (And this will be the hard part for some of you)
9752F is what Jp4 "freeburns" at. Freeburn is a Pyro term for "lay it on the ground and burn it" No wind, nothing else feeding the flame, just the material in a lab setting generating heat.
1220F and 3034F is what those materials used in the majority of construction of an aircraft MELT at. (I am sure we all know what melt means)
Now that’s a good 6718F left unaccounted for on the Titanium alone, not to mention the 8532F on the aluminum. And just for the sake of argument we wont even get into ambient heat generated by all the other stuff involved raising the temp even more.
Ok, I am no metallurgist, but I am however a chemist and a pyrotech. The possibility of those two metals *not* "ashing" in that kind of heat is down right silly. Especially when we have all done the "throw a coke can" in the camp fire bit, and seen it melt and ash with our own eyes. You telling me a camp fire burns at OVER 10,000F?? That’s a hellava camp fire! (That’s also called practical real world evaluation, fancy term for we know its true, and can prove it over and over)
Believe what ya want, watch some flash vid telling you what you want to hear, or would like to hear. But the plain (no pun intended) fact of the matter is, an aircraft hit that building, Jp4 spilled out from ruptured wings and then burned/ashed what was left of the small bits that were left solid and didn’t disintegrate on impact. I could go one to punch holes in the video especially with the pic of the "motor" bits seen by the fire fighters, but why bother if this will not get some folks to see facts nothing will.
A flash animation on the net showing pictures that have been edited to a point that the local village idiot would Believe it means nothing to me. The numbers, the facts of the materials involved, sitting there in black and white.. that’s what matters. "