Decades ago, airliners were quite noisy and vibrated significantly in flight from the piston engines that powered them, and with the eventual introduction of jet propulsion and turbofans, flights became much smoother and quieter. It is about to happen again. The transition to electric flight propulsion will practically eliminate powerplant noise and, though propellers will still generate sound, electric power will provide the smoothest, quietest passenger experience yet.
The adoption of electric propulsion has begun with many manufacturers delivering certified aircraft and many more airplane manufacturers cued up for certification to open their own production lines in each of the next several years. This roundup is a representative sample of electric-powered general aviation (GENAV) aircraft that are established or soon coming to market. Electric motors are quieter and have a smaller operational carbon footprint, with zero emissions, compared to an equivalent internal combustion engine, and require less maintenance. Although wet fuel has far greater energy density than current batteries, electric propulsion systems are more efficient than combustion engines and have constant torque across all speeds, which simplifies the engineering of aircraft control systems.
Jet fuel has an energy density of about 12,000 watthours per kilogram (Wh/kg). Lithium-ion batteries have an energy density at the cell level of
