Originally Posted by gridlockd
So it was emitting an energy up until it hit the ground? So if they know where it went down, just concentrate your search in that area. Would it take even 5 years if you know where to look? Just seems like they want it both ways, Stark has all this crazy cutting-edge technology but oh, we don't have the technology to find this giant ship in the snow. I'm not saying it ruins the movie but again, the filmmakers themselves obviously saw that this way an issue or they wouldn't have added that pre-emptive expository dialouge.
You misunderstood the movie. The plane never emitted an energy signature. It was the cube. "But the energy signature stop's here." The cube was emitting an energy signature, the plane never did. They didn't actually know where the plane hit the ground. Hence why it was basically impossible to locate.