investigation? does it change the investigation? >> well, theoretically it would shift the probability but can't determine anything for sure because of the problems of reliable, because there's different reasons why you might not hear it. we can't say, well, it deaf t it inially didn't. for instance, when captain s sullenberger land it in the hudson it didn't set off because it was a fairly gradual, gentle -- >> miracle on the hudson. >> right. >> inside this. this is operated by a lithium battery, correct? >> okay. >> and these have been known to -- lithium batteries have been a fire hazard. >> right. you might have heard about the 787 dreamliner that there was some smoke and fire in a plane and that caused some hull damage actually to a plane that was on the ground in england. and that was a different configuration from the 777. >> these are all things that investigators and searchers are looking into. >> yeah. >> every possibility. no stone is being left unturned. >> at this point we've got so