positively linked to the aircraft, then you can run a retro navigation exercise which will take you back upstream, upwind. a mix of oceanography, mathematics and a little bit of art. >> how long will that generally take? a matter of hours or days or weeks? >> weeks. you can do a rough calculation in a couple of days. in order to keep refining that search area down, the more time, the more analysis you put into it, the better it gets. if you look back to air france, the aircraft was located a couple years after the pinger batteries were exhausted. using these retro navigation techniques to get to a point of impact, what you'll see in the next few days assuming that some dbris is found is a timing shift from this urgency to find debris as fast as possible, you'll see a shift to wanting to not be so fast but very, very