large AMOUNTS.
Large
parts on the other hand--meaning identifiable pieces and structures of welded together components that serve an identifiable function--that is a different matter.
They do have pictures of wheel hubs, landing struts, tire chunks, engine components, the odd piece of passenger seating--mostly the harder parts of the plane that typically survive highspeed impacts and are not only hard and dense but also unique enough to be easily identified. See pictures of Pentagon crash 757 parts
here.
Unidentified twisted shattered pieces of structural aluminum and scraps of confetti like aircraft skin--they got truckloads of that, but there's not much to learn from it since it's so destroyed and scattered by the sheer violence of the impact and explosion.
There's more aluminum skin visible on the Pentagon lawn in well publicized photographs taken while the fires are still burning,
just on the lawn not even counting all the debris inside, than would be required to skin 3 global hawk drones. And I doubt the Global Hawk even has a metal skin.
Welcome to DU don't let the moonbats get you down.