Pictures are dated, not timed (not that I could see).
All I know about the archives is that once the order has been made, it can't be changed. So if it was ordered that the JFK files (only some of them apparently) were to be sealed for 75 years, then that's what's going to happen.
From these links:
http://www.defenselink.mil/news/Sep2...200109153.html
http://www.defenselink.mil/news/Sep2...200109146.html
You can find out a little bit more about how the building was reinforced. You have to admit, the Kevlar on E ring is not exactly a common type of protection.
It seems clear though that the plane did go through the E, D and C rings, and stopped outside of B ring.
From this one:
http://www.defenselink.mil/news/Sep2...109139f_hr.jpg
It's clear that the fuel spread quite a distance behind the point of impact. It was obviously worse past the point of impact.
Here's some testimony, from an insider point of view:
http://www.defenselink.mil/news/Sep2...200109132.html
The black boxes were recovered 3 days later:
http://www.defenselink.mil/news/Sep2...200109142.html
Civilians (family of victims) visited the crash site, only 5 days after impact:
http://www.defenselink.mil/news/Sep2...200109165.html
I'm no "plane crash reconstruction" engineer, so I'm not going to even try to measure the flameball, but I'll point this out: The 757 can carry many times more fuel than any "small airplane".
Titanium doesn't melt indeed, but a running engine coming to a sudden stop will come apart, and given the fan speed, will come apart quite explosively, fuel not withstanding. I wouldn't be surprised if they found more engine parts imbedded in the building, 20 years from now.
A 757 strangely enough can look like a small plane. With 2 engines under the wings, it is unique from small planes, which usually have 2 engines on the tail. It certainly cannot be compared to a 747 though, as it has 4 engines under the wings, and would, by far, have created much, much more damage.
Having seen planes close up (Embraer RJ140 class, CL-65, DC-9, A319, A320, A330, A340, B767, B747), I can tell you that the bigger airliners are actually much bigger than they appear. The height of the tail fin on the 747 is particularly impressive. The jet blast from those bigger airliners is much more poweful than what a measly 8-10 plane can do: A 757 engine will sit about 4 feet off the ground, and has a rated power at least four times that of a small jet. A small jet's engines sit at about 8 feet above ground.
AA jets are not painted (metallic) grey, they are polished to a mirror.
So if the plane did penetrate three rings, what caused the entry hole to be so small, is what the question should be.
It seems that the reinforcement worked, in that the plane got crammed in a hole smaller than its original size. If it hadn't, it would have flown right through all 5 rings, and hit the backside of the Pentagon building. The exterior skin and supporting structure excluded, the plane is just a heavy platform, narrower than the exterior body. If the plane got squished to the base platform, it would explain the collateral damage that comes with an entry points of a heavy structure. In other words, the base platform (which is about the size of the hole) entered the building, causing the hole to be the size that it is. The skin exterior was not a factor in creating the hole.
I don't believe that a small plane (engines included) could be made to crash through 3 rings.
Well, that's my "devil's advocate" bit for the day...