CNN The Situation Room April 7, 2014 21:20:00
>> do you think it's possible that the batteries may have run out during those 24 hours because we know they usually last for about 30 days and we're now in day 31. >> yeah, that's certainly a big factor, the race against the clock. so a couple big challenges. one, like you said, the batteries at any point could die down and the second thing is, the effectiveness of our towed pinger locator really is only as good as the strength of the signal coming out of the pinger. so as the battery dies down or if we're just not in range of about a mile, which is not a long distance at all, then the tpl is...