Spinout of Karem Aircraft developing the Butterfly, a five-passenger tilt-rotor eVTOL using Optimum Speed Tilt Rotor technology for low-noise urban operations.
Overair is a Santa Ana, California eVTOL developer that spun out of Karem Aircraft in 2020. Its flagship aircraft is the Butterfly — a piloted, six-seat (1 pilot + 5 passengers) tilt-rotor eVTOL using Karem’s Optimum Speed Tilt Rotor (OSTR) technology, originally developed for the US Defense Advanced Research Projects Agency.
OSTR varies rotor RPM in flight to keep blade-tip speeds in the most efficient and quietest band, giving the Butterfly a target range and noise profile competitive with the best of the urban air taxi field.
UK-based developer of the VX4, a piloted four-passenger eVTOL targeting EASA and UK CAA certification with backing from American Airlines, Avolon and Virgin Atlantic.
California-based eVTOL operator developing the Midnight, a 4-passenger air taxi designed for back-to-back 20-mile city hops with minimal recharge between flights.
Canadian-American developer of Journey, a slowed-rotor compound (SRC) eVTOL that combines a helicopter-style rotor with a fixed wing for efficient cruise.