On the contrary, it was one of the busiest days in the history of American aviation, a dense forest of live fly exercises, drills, simulations, fake radar injects and utter confusion. And that was before the attacks even began. This is the story of 9/11 that you didn't watch unfold on your TV that fateful day in 2001. This is the story of the 9/11 War Games.

TRANSCRIPT

When we remember the events of 9/11, we are often invited to reflect on how the attack came out of the clear, blue sky. Until the terror began to unfold in real time on everyone's television screen, it was just another beautiful, blue sky day, a perfect day for aviation.