water and then sunk why has there been no signal coming from the electronic transmitter? shouldn't that have sent out some kind of beacon? >> technically, john you're absolutely right. it should have. i don't have an explanation of why that appears to have failed. it may well have been destroyed in the, in when the airplane impacted the water. or, it just may have malfunctioned. it may be as simple and as tragic as that. >> one thing we're talking about is that these planes routinely try to fly around thunderstorms. they deal with this weather on a fairly regular basis. and when it comes to the a-320, it has sophisticated equipment when it comes to radar, but not the very latest equipment, but does it sometimes have problems with thunderstorms? ? well, look it's a very interesting point. with particularly in relation o to the radar.