Forgive me for being a naive ATCO but if TCAS did not exist, the accident at Lake Constance may not have happened! The Russian ac would have descended and the DHL ac would have maintained its level. Equally, the programme touched upon a very near miss near Japan that was put down to TCAS. Given these occurrences have any studies been made of the incidents caused by TCAS rather than those that have been resolved by it. Are we all looking at the Emperors new clothes?