Im thinking here of a wikispeed personal aircraft...
What principles are used at Wikispeed that would help manufacture aircraft better than what we're doing now?
The hardest part of designing an aircraft isn't designing it, 90% of it is passing all the damn tests to get it certified and getting certification on every damn little thing you want to do. Sadly, a major part of what makes an airplane design "great" is how long it's been flown without any problems, as safety is on more people's minds than features.
Here's where you start:
http://www.faa.gov/licenses_certificates/aircraft_certification/airworthiness_certification/
Sure, it would take capital to do the paperwork, but you can crowdsource the tests to people who are building prototypes along with you. You each specialize in one area and send parts around. That's how.
So the Wikispeed secret is to find qualified unpaid volunteers willing to risk their lives as test pilots all begging to be the first to climb into some untested contraption and hit the throttle? I could see how this might work for space travel (moon or bust!) but not for a new personal aircraft paradigm.