Insider's Taylor Rains sits aboard Archer Aviation's upcoming Midnight eVTOL.Taylor Rains/Insider Electric planemaker Archer Aviation is one of the most promising eVTOL startups in the US. Overseeing safety is the former acting head of the Federal Aviation Administration, Billy Nolen. His appointment comes ahead of Archer's upcoming Midnight eVTOL, which United plans to fly. One of the highest authorities on aircraft safety in the US just placed his bets on startup electric planemaker Archer Aviation, representing how close the world could be to this new era of air travel.In June, former acting head of the Federal Aviation Administration, Billy Nolen, stepped away from the regulator to become Archer's chief safety officer.