pilot is asked to fly above a storm, to raise their altitude. how high does a plane need to go to avoid storms like this? >> in that region of the world, that particular plane cannot top a thunderstorm. those thunderstorms are going in excess of 55,000 feet with those temperatures and the upward lifting development, that plane isn't even certified to fly that high. the other thing is when the plane continues to climb, the performance envelope of the plane reduces. it's limited on bank angle. you just don't have the controllability at those altitudes that you would at lower altitudes. in addition if there's any turbulent air, that can put the plane into an upset condition or where a plane actually departs controlled flight. >> david, there was no way to top this storm, going as high as 50,000 feet. there were reports that there were other planes flying at higher altitude.