Good, now tell us why the results of the Iranian crash were somewhat different than PSA 1771 and 592. This is something you should have figured out by now.
HINT:
tmd, I understand the differences very well. The point you should have gotten is that not all crashes leave significant parts. Slower velocities will have less kinetic energy and the trauma will from a relative standpoint be less. Then you have examples like 592 and 1771 which were steep angled, extremely high velocity crashes that involved exponentially higher kinetic energy than the Iranian crash, and fragments no larger than a human ear were found.
The crashes into the WTC were 450-500 mph crashes. Then they were subjected to 500,000+ tons of force when the buildings collapsed. I'm not surprised by this; why are you?