5 years ago, the skies over America were silent – no commercial flights, no private planes, and nothing flying other than birds and the occasional jet fighter on patrol over major cities like Chicago. I will never forget the leaden feeling of dread and grief that I carried around with me those first few days and weeks. During the nation-wide “flight hold,” it was hard to sleep at night, because the familiar roar of jets overhead on their way into and out of O’Hare was absent. The lack of something that I had previously found mildly annoying made for long,…