Ed Felt's Phone Call from Flight 93, Revisited

This phone call is typically completely ignored by the official 9/11 conspiracy theory, as it is so odd.

Summary (from ):here

1) at 9:58am, Felt calls 911 on his cell phone from the bathroom of flight 93
2) the call connects to a local 911 dispatcher, who takes the call, and also calls his supervisor to listen in
3) the call only lasts 78 seconds
4) Felt is very distraught, says the plane is going down, talks of an explosion and smoke
5) this part of the call that mentions an explosion and smoke is removed from a NYTimes article on the call, though the explosion and smoke is clearly in initial reports of the call

The oddest part here is that Felt seems oblivious to the passenger attack against the hijackers, which was well-organized by this point and was just starting to take place. Why was Felt locked in the bathroom when the passenger attack just starting?

And ironically enough, though officially the plane had been descending rapidly for many minutes, at 9:58am, the plane leveled off then climbed!

So little about Felt's call adds up, and certainly the fact that the 911 operator/supervisor who took the call was gagged by the FBI is odd. At minimum, we can conclude that there is some sort of cover-up here. AT worst, it suggests a different level of legend was created for flight 93, and this was discarded when the passenger heroic story became popular.

But what was this explosion and smoke, and why has this been ignored?