recording. both british and u.s. officials have said intelligence suggests a bomb may have brought it down. these revelations are sparking changes in security. how safe is it to fly? joining us, a former nas official joins us with the latest. first the obvious question, are you convinces of the likelihood this was a terrorist act? >> it sounds more likely than not. there's only a certain number of explanations for why a plane would blow up, obviously. and the investigators have to rule out all of the different options. and the more they find out, the forensics will help and obviously the intelligence that's being collected. it sounds more likely than not given what has been stated so far. >> we would assume/hope that security in the united states would respond to this in ways that we're not seeing. has it? >> there's a number of things