miles on the west coast of malaysia and half covering the same area on the east coast. so they're not moving all their assets into where this plane was last seen, because they still don't know the identity of the plane. that's where we are at the moment with that. what you're talking about, the pilots, the pilots -- the chief pilot, 53-year-old, police did visit his home. he was an aviation nut. he has been described as he had a simulator and flying simulator in his house. police have been there. they say it's part of the routine investigation, leaving no stone unturned, chris. >> okay, good. so that's just about them checking, as opposed to them having any cause for speculation involving the crew. it's good to at least rule that out for now. one follow-up question for you, andrew. is -- help us understand, if they're trying to figure out if this was the plane, why is that difficult, other than the unsophisticated nature of this primary radar? doesn't give you altitude or flight speed, and a lot of the data, more so physician rated radar does. could it be another flight, were there other planes in the area? what are the variables involved?