By Isabel Goyer If you’ve been flying for a long time, you know that even the best airplanes involve significant compromise. And designing an aircraft that has all the necessary qualities of a good family transportation platform…well, that’s a tall order. Why? It’s all because of that pesky slice of reality known as physics. In order to build a plane big enough to haul a bunch of people, it has to be roomy, which means big, which means more structure, which means more weight, which necessitates more power (i.e., a bigger engine), which means more weight and more gas, which equals more weight. …