There was a FOI request for the tapes. It's on the web somewhere (I don't have the URL handy).

There were were something like 68 'tapes' confiscated. Of those, only two showed the actual aircraft approaching the Pentagon.

They were being withheld because they were evidence in an investigation.

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"For ignorance to reign, all it takes is for knowledgable people to say nothing"

Lonewulf