[sp332]

The goal is just to narrow down the search area after a crash. Even at 700 MPH you can only cover 175 miles in 15 minutes. That's a pretty tractable area to search for a blackbox ping. And that's if they have no other info about the crash.

[greedo]

100K square miles is a pretty big area to search. Actually more than that since a plane cruising at 30K feet could glide quite far if it maintained some airframe integrity.

[sp332]

Yeah the search area would be about the size of New Mexico. But a larger area than that was searched in one day, Wednesday March 19 2014. http://www.nationsonline.org/oneworld/map/malaysia-MH370-sea...

[gsnedders]

By way of counterexample, note we knew pretty well where AF447 crashed and it still took almost two years to locate the wreckage on the sea floor.