Purdue gjorde simuleringar och skriver:
""At that speed, the plane itself is like a sausage skin," Sozen said. "It doesn't have much strength and virtually crumbles on impact."
But the combined mass of everything inside the plane – particularly the large amount of fuel onboard – can be likened to a huge river crashing into the building.
(...)
Because the structural skeleton of the Pentagon had a high level of toughness, it was able to absorb much of the kinetic energy from the impact," said Christoph M. Hoffmann, a professor in the Department of Computer Sciences and at Purdue's Computing Research Institute."
http://news.uns.purdue.edu/html4ever/020910.Sozen.Pentagon.html
Deras simuleringar finns här:
http://www.cs.purdue.edu/homes/cmh/simulation/