mm43,
Using the back of an envelope, and after checking a few different announcements, it seems the search has been narrowed down to about 900 square miles (give or take a few), which is roughly a square of 30x30 miles, which would mean the actual impact point has been narrowed down to 3° 22'N 30° 45.5'W plus or minus 15 miles.
Statute or nautical miles? Not a huge difference anyway...
It still seems a pretty limited area, in view of all the incertainties about the debris field on the surface, and the local currents and winds at the time.
And 600 mph is 60 miles per minute, so again they think they've pinned down the time of impact to within a minute and a half?
It's only just the back of my envelope.... and yes, I truly wish them success, and luck... they'll probably need it!
CJ