http://edition.cnn.com/2016/07/05/aviation/clip-air-pod-airplane-concept/index.html
It's not strange to invent such a strange shape of the aircrafts. The first aircraft was invented just a hundred years ago. But just a hundred years later, (tens of?)thousands of aircrafts are flying everyday. And, more than a hundred types of aircrafts were developed.
But, I think that it's easier to develop one decker airplane than developing three deckers airplane which has the same capacity as the former one.
