Complication: when the plane's "secondary radar" stopped (the transponders that report things like ID and altitude), both Malaysian and Vietnamese "primary radar" could still see it (the unassisted bounce back of the radar's radio waves). If they saw two biggish pips in the general vicinity they'd likely have said something by now, at least the Vietnamese, who've got to be getting annoyed by Malaysia's handling of this. E.g. per Wikipedia 'According to the Vietnamese deputy minister of transport, Pham Quy Tieu, "We informed Malaysia on the day we lost contact with the flight that we noticed the flight turned back west but Malaysia did not respond."'
Sorry, I wasn't clear enough, and thinking further, probably wrong on the main point:
You postulate two planes in the same area, that would look roughly the same on primary radar when their transponder was off (or maybe I misread you/assumed incorrectly about both looking big, see below). "Biggish" in that the 777 is a rather large aircraft with a presumably large radar cross section, "pip" as in a blob of light appearing on the radar's screen.
Going further, when they looked at the recordings of what their radar(s) saw, they'd see one "biggish pip" suddenly returning transponder information and another stop ... it's hard to imagine coordination to the split second, although it's possible.
Ah, I see one way in which I could be wrong: assuming the use of a small jet, it could be configured with a powerful enough transponder to simulate the 777's. So both pips would not necessarily be big, and if the location was carefully chosen maybe the small jet's wouldn't be seen by the radars. And that's more likely, after all, if they had a big jet to start with....
So what you're saying is I'm 100% correct and this is definitely what happened?
But back to being serious for a second. If mh370 really did keep on flying for five hours on the route that has been suggested, is there any other way it could go unnoticed? I'd like to think that it's impossible for something the size of a 777 to fly unhindered through the sky over several countries post 9/11. But then again, I had hoped someone couldn't make a plane vanish seemingly at the flick of a switch.
You seem to know your onions, is it possible to have two planes flying close enough together that they show up as one blip on radar? What's the pixel to kilometre ratio on those things?
Heh, I deduced a way it might be possible, assuming sufficient coordination.
I don't know specifics of radar, just the general principles. The major possibility here is that your suggested transfer of which transponder is saying "I'm MH123 at the same altitude" happened at a range where no radar would be giving a good enough return from the putative small jet assuming the role. Which upon review wasn't the scenario you were positing.
And if it was giving enough of a return to be seen, especially in retrospect as experts reviewed it, well, we'd have heard about it by now.
But if AB123 was big, we'd really have heard about it and it's near collision with MH370, or someone would be wondering why AB123 moved really quickly a noticeable distance at the same time MH370 went off the air. Or perhaps AB123's altitude was different, they were far enough the radars' couldn't tell that, and it's transponder was customized to lie about the altitude.... But people would still wonder, and would be questioning AB123's flight crew if they saw anything, etc. etc.
(I'm tired enough the above isn't entirely coherent, but it'll give you some things to chew on.)
Again, I would like to stress that I know all of this is unlikely, but there's is no reason why both planes would need to coordinate this down to the second. Mh370 goes offline, takes an hour to get into position with ab123. Then they make the switch.
Once mh370 goes missing, it stays missing. The trick is in making it look like ab123 is behaving normally. And while everyone is distracted by the search for mh370, I wonder how closely they would be looking at irregularities in other flights that aren't missing and aren't reporting any problems.
