>> ian, thank you. let's bring in cnn aviation analyst peter goels and michael wi wise, an author. peter, to you first. 99.9% certain is what one official says. what more do they need to become 100%? >> i think the only thing they need is for the egyptian government to acknowledge that this was a terrorist act. they have the information they need to make -- the voice recorder will have a sound at the end of it. it can be analyzed, it can be compared to previous terrorist acts. you know, you could look at the pan am 103 bombing over lockerbie and compare that sound to this sound. they can tell whether it is a high order explosive or not. now the egyptians have to bring forth the physical evidence that