then if the Pinger is activated every 30 minutes, they must KNOW the location of the aircraft plus or minus 250 nm?
Yep, I'm sure they do. But you're looking for a 200' x 209' aircraft in a 250NM search square - and it's in pieces, and 90% of it has sunk after 7 days. Good luck with that.
http://cdn.lowyat.net/wp-content/upl...r200_300lr.gif