Spoofing/faking another flight
I'm sorry if this has been touched upon before, but a search in this thread for "fake flight plan " doesn't return any hits. So:
Could whoever piloted MH370 have filed a "fake" IFR flight plan for "Whatever flight XXX/Private XXX" in advance and then, when the aircraft had been disappeared over the ocean in an area without ATC and radar coverage, simply present himself as "Whatever flight XXX/Private XXX" in accordance with the filed flight plan to ATC when entering controlled airspace, set the ACs transponder to the designated squawk and then all of a sudden be a legit flight being able to travel in controlled airspace without anyone including military types noticing (for the time being at least)?
Or would ATC know in advance that "Whatever flight XXX/Private XXX" had in fact never taken off from it's filed origin and therefore flag it as trouble? Does - or rather must - the ATC handing the aircraft off into uncontrolled airspace advise the ATC in the other end that "Whatever flight XXX/Private XXX" is approaching in accordance with filed flight plan?
(With a Mode S XPDR I guess you really can't unless ATC doesn't couple the transponders ID with the ICAO database or doesn't notice the discrepancy, but can the pilot of a 777 toggle the transponders mode and run in ie mode A/C?)
((Asking because I'm trying to weed out a conspiracy that's pretty much off the top))