Sorry pal but I read ALL of the info on the PASSUR web site. PASSUR uses the return information but is also fed info from the ASR. In the event that the ASR returns a signal (ghost or not) PASSUR thinks it has to assign a designation to it (I believe - computers doing what they think is correct). Clearly evident by clicking on the icon on the dual radar track from PASSUR - the FAA ATC tapes may not have designated the bogey as the AA flight. By your explanation the bogey return the same IFF codes as the AA flight at least as far as PASSUR was concerned. How could that be? TCAS is NOT implemented on ALL commercial aircraft. ONLY those with FAA oversight. Many foreign freighters and other aircraft do carry TCAS. Also, it is entirely possible that this was another aircraft that wandered into the airspace with it's IFF turned off. I can turn IFF off on my plane anytime I want. Is it also possible that there a drug runners who have IFF spoofing capability (unlikely a 13:00 in LA but if the money's right)? EA-6B's can do it with the flip of a switch and they can return the appropriate radar signature for any aircraft they want. Did the AA pilot report a TCAS warning? I have not heard that if he did then the whole thing is probably just one big snafu.
Do a little more research. The only data PASSUR receives from an ASR system is 1030 MHZ interrogation data (transponder data). If the target isn't transmitting an IFF code, it won't show up when it is interrogated by an ASR system and there is nothing to be sent to the PASSUR system.
"the FAA ATC tapes may not have designated the bogey as the AA flight."
Where have you seen those?
"TCAS is NOT implemented on ALL commercial aircraft. ONLY those with FAA oversight."
Again, you need to do more research. TCAS is currently required on all commercial aircraft (part 121) and all cargo aircraft with a max takeoff weight of more than 33,000. The same is true internationally.
"Also, it is entirely possible that this was another aircraft that wandered into the airspace with it's IFF turned off."
Then it would have been seen by ATC radars used to track raw returns (not transponder data) and would have been reported to AA 612.
"I can turn IFF off on my plane anytime I want."
Yeah. And do it in Class A airspace (where this event occurred) and then you really will see fireworks. I've been scrambled for similar events.
"Did the AA pilot report a TCAS warning?"
No, which is really all the proof you need that what shows up on the PASSUR display is a ghost image. If it were real, AA 612 would have been climbing and diving all over the sky to avoid a collision.