the airliner take beforehand? martin savidge is in a flight simulator for us. martin, what were you able to figure out from the location of the reported pulse signals. >> well, there's a lot that we still don't know. i mean, we know where this pulse comes from. we have been charting a lot of this stuff out on maps and computers. what we are doing right now is flying 777, of course, laid out exactly the same as 370. we are over the straits of malacca headed in a southwesterly direction. this is after the significant turn that the aircraft made and following the route. we set the plane at 25,000 feet. that's the big thing we don't know what altitude did the aircraft fly after it disappeared off radar. so we basically figured out by looking at the maps and where this ping was heard it makes sense from what we knew about