Thanks to u/passivecensus for turning me onto loopDloops posts on the now defunct "let's roll forums", about the Flight 11 phone calls on 9/11.

loopDloop chose this one aspect of 9/11, the Flight 11 phones calls, and did an exceptionally deep analysis based on new documents and transcripts that were released around 2012. The posts were published gradually over a couple of years, and in the end another user there produced a well formatted pdf of all loopDloop's research, including images and screenshots etc:

http://www.911conspiracy.tv/pdf/Fog_Fiction_and_Flight_11_Phone_Calls.pdf

It's like a 176 page monograph on the oddities, dubious content and provenance of the phone calls that were made from Flight 11 on 9/11. There are many insights here I was unaware of, and that no "mainstream" 9/11 researcher/truther has really picked up on. In truth, it's exhaustive to the point of being a little tedious or boring perhaps, but if you give it a chance, the little odd things and facts and changing transcripts and utterances from people, both then and during the passing years - they blow apart the idea that those calls were genuine.

Among the many fascinating insights made by loopDloop - it's proven pretty early on that the official recording of the Betty Ong call has been tampered with in various ways. It is even demonstrated that it was tampered with between September 11 and 12, 2001. This only became apparent in 2012 with the release of transcripts. loopDloops explanation? Ong, who was likely (or believed she was) participating in one of the many drills being enacted that day, didn't do a good enough job with the call, and it had to be quickly edited on the fly to guide the narrative and remove uncertainties.

Highly recommended.