His most brilliant insight wasn’t some advanced breakthrough in the science of flight. It was simply that focusing on the elegance and sophistication of the aircraft was actually an impediment to progress. An ugly aircraft that could be crashed, repaired, and redesigned fast would make it much easier to make progress on what really mattered: building a plane that could, as MacCready put it, “turn left, turn right, go up high enough [at] the beginning and the end of the flight.”