You're standing on top of the Sears Tower in Chicago. There's a swarm of cameras on the ground and in the air ready to capture your death-defying jump. And then, Michael Bay yells, "Action!" That's when J.T. Holmes, Julian Boulle and the rest of the "Birdmen" jump, soaring through the Chicago skyline, torquing their bodies to avoid crashing into buiildings. In a new featurette promoting Transformers: Dark of the Moon we get a behind-the-scenes look at the high-flying stunts. Check out the video below. Transformers storms into theaters June 29th.