Once in the air, almost anyone who has a basic knowledge of the controls and
a couple gauges, can fly. I worked for a charter company as a ramp rat for a
few years, and got to grab the yoke of a King Air 100 and 200 during
post-maintenance check flights. Even in a smaller twin turboprop, keeping a
level flight isnt that hard. And by the way the planes hit the buildings
with course corrections right before impact, just shows theres a little
terrorist in all of us. And those who did the flying, had recently learned
the basics too.
The estimate was 1/3 of the fuel flashed on the outside, and the other 2/3
started the office materials burning. The impact plowed a lot of materials
out the other side, just not hardly enough to keep the fires down. Estimates
on the temps were around 1500 to 2000 degrees i believe.
As far as the "why", everyone has their own opinion on that, and i wont
waste anyones time on it.