Maybe I missed the gist of your conversation about this, but was it about no evidence of a plane at the Pentagon?
If so, take a look at this photo.
Hull part?
Doesn't look like either airlines to me
Nor does it match this hull part of the plane at Pentagon
http://images.search.yahoo.com/search/images?p=american+airlines+hull+&ei=UTF-8&fr=FP-tab-img-t&fl=0&x=wrt
Look on the left red/white Atlas ICBM
Then the cruise missile