I've read the aerospace web "theory".
Everythnig on that page is estimation and approximation. Therefore it means nothing to me...
Every air disaster matches up parts with the airframe serial number. Aircraft have maintainence (mx) logs for this purpose. The logs show every directive, every service bulletin... and every part swapped out due to AD's. Just because engines are modified since original from the factory (most engines are.. aviation is a trial and error industry).. its still documented in the MX logs and must be looked into. The govt can easily match these parts to squash anyone who thinks it was other than a 757. But they dont offer anything but speculations, theory and stone walls.
The NTSB is in charge of investigation into any air disaster... even if it has criminal implications... (edit: let me clarify... they will hand over power to the FBI in criminal cases, but they still conduct the investigation.. since they are aviation experts. In the case of Sept 11, they had their hands tied)
Here are some of the major investigations...
http://www.ntsb.gov/ntsb/major.asp
You will notice in depth analysis of every disaster.. except Sept 11.
NTSB report for AA77 (Pentagon)
The terrorist attacks of September 11, 2001 are under the jurisdiction of the Federal Bureau of Investigation. The Safety Board provided requested technical assistance to the FBI, and any material generated by the NTSB is under the control of the FBI. The Safety Board does not plan to issue a report or open a public docket.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The Safety Board did not determine the probable cause and does not plan to issue a report or open a public docket. The terrorist attacks of September 11, 2001 are under the jurisdiction of the Federal Bureau of Investigation. The Safety Board provided requested technical assistance to the FBI, and any material generated by the NTSB is under the control of the FBI
http://www.ntsb.gov/ntsb/brief.asp?ev_i ... 0105&key=1
NTSB Report for UAL 175 (South Tower)
The terrorist attacks of September 11, 2001 are under the jurisdiction of the Federal Bureau of Investigation. The Safety Board provided requested technical assistance to the FBI, and any material generated by the NTSB is under the control of the FBI. The Safety Board does not plan to issue a report or open a public docket.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The Safety Board did not determine the probable cause and does not plan to issue a report or open a public docket. The terrorist attacks of September 11, 2001 are under the jurisdiction of the Federal Bureau of Investigation. The Safety Board provided requested technical assistance to the FBI, and any material generated by the NTSB is under the control of the FBI.
And the same report for AA11 and UAL 93 (conserving space)
I havent looked at every NTSB investigation and report (there are literally thousands)... but i think this is unprecedented.