Hard to believe that such an aircraft could just disappear and fly somewhere to completely undetected...
However all sorts of scenarios could be in play from the US being completely focussed on the situation in the Ukraine to just the plot hatched to coincide with crew-change time/nap-time in the various installations and the plane flown at such an altitude and manner as to evade normal detection...
It could be that the pilots/hjackers cannot believe their luck to have so far evaded detection and are reformulating their plans to take advantage of the new collection of opportunities that have been handed to them with possession of a marketable plane and parts worth some $250million or so...
