There is something not quite right about this.
The same flight has been considered an extreme threat for three days now.
I think it's a fair to assume that the flights were canceled because there was someone, or something, on board that was considered a terrorist threat.
Was this same threat present on all three flights?
If so, surely it would be easy to isolate and neutralize?
Conversely, if they don't know quite what they are looking for why are they being so specific about this particular flight?
Something just doesn't sit right.