point. >> we always hear that if you're a pilot in a tough situation, the order of business is aviate, navigate, communicate. if we're talking about a six to eight-minute descent, is that a long time to not talk to ground control and say, hey, guys, there's something going on here? >> it is kind of a long time to not announce your intentions. normally even if you are on an oxygen mask in depressurized plane or plane filled with smoke, you're going to transmit on the radio and you can send transponder to the emergency code that air traffic control would pick up. and you would still be able to communicate with the outside world. if they are overcome in some fashion either pressurization increased to high or weren't able to get oxygen masks on or overcome by smoke, they may not have been able to respond. if the airplane was in a controlled descent and constant air speed, it seems like they