Jabberwalker Jabberwalker:
The old collision avoidance system worked but only just. with a closing speed of 1200MPH, it has to react immediately. If both crews climb, or if they both dive at the same time, it's game over for both of them.
Old? The Traffic Alert and Collision Avoidance System is the last line of defense in avoiding a collision. The air traffic controllers cleared each of them for altitude and course which put them in that position. They are allowed a buffer of five miles laterally and 1,000 feet vertically. Someone either put one of them at the wrong altitude or one was set at the wrong altitude. Usually opposing flight directions are given either odd or even flight altitudes to give them the minimum 1,000'.