Archer Aviation (ACHR -5.18%) is developing electric vertical and takeoff landing aircraft (eVTOL), which could potentially transform urban transportation as we know it. These vehicles, also known as flying taxis, are possible because of modern battery technology and have attracted investments from companies like Boeing, United Airlines, and Stellantis. While this technology is exciting, there are some hurdles Archer Aviation must overcome to reach commercial operations. If you're considering investing in A ...