don't they make transponders in a plane which cannot be switched off by the pilot. and he said that is a debate that is still very much alive in aviation circles because there are good security safety reasons as to why those transponders should be allowed to be switched off by the pilot. but that debate is still going on zain. >> andrew stevens live for us in hong kong with what you could say is a bit of a silver lining of better track planes. >> thanks andrew. south korea's president has made a surprise visit to u.s. ambassador mark lippert in the hospital. lib pert is recovering from surgery to put 80 stitches in his face. a hospital spokesperson says he will be released on tuesday. >> now authorities say a man opposed to joint u.s.-south korean military drills slashed lippert's face and arm with a nice on thursday. you see his reaction, just in shock. now officials from the international atomic energy