Temperatures are dropping, the leaves are falling, and the countdown is on to the busiest time of year for air travel around the nation. The industry association Airlines for America predicts 24.6 million passengers will take off to visit friends and family during the upcoming Thanksgiving holiday weekend, up 1.5 percent from 2013. Sunday, Nov. 30, will be the busiest day of the year at U.S. airports. Even if you won’t be taking to the sky anytime soon, it’s a good bet something you're using today– your cell phone, flat-screen TV – or the holiday gifts you're buying online arrived as part of the billions of tons of cargo shipped on airplanes every year in the U.S. The holidays reinforce how much we rely on aviation. And thanks to advancements in aeronautics developed by NASA, today’s aviation industry is better equipped than ever to safely and efficiently transport all those passengers and packages to their destinations. Streamlined aircraft bodies, quieter jet engines, techniques f...