>> thank you. >> a few things we should wade through here. first off, the search coordinator angus houston discounting radar equipment that indicated these altitude dips, something we talked about right here on cnn. the plane went up. it went down. you have said from the beginning, if i go back through my mental hard drive, had you said from the beginning that the altitude data was an assumption. is that primary radar even reliable for determining altitude? >> not for altitude, no, not for altitude, mike clampt it's really designed to tell you where the aircraft is, what direction it's going and what speed it's going. it has to be very carefully calibrated and looking for altitude. in addition to that it needs a secondary primary radar to give them verifying radar as well to be very accurate about altitude so i'm really surprised and a little disappoint that had they actually used that in their calculations to determine the fuel consumption. it's really surprising to me. >> help me understand that.