According to Rotor and Wing, Jaunt Air Mobility has bought into the Carter Copter concept and are looking into its feasibility as an Uber air taxi.
In April 2017, Carter Aviation partnered with Mooney International Corporation to develop an eVTOL.
Carter use’s it’s Slowed-Rotor/Compound (SR/C
In own words.
It couples the speed, range and efficiency of an with the vertical takeoff and landing capability of a helicopter along with the unparalleled safety of a high inertia rotor. Whether incorporated into a jump takeoff configuration or a powered rotor variant with continuous hover capability, SR/C technology offers extraordinary cruise efficiencies and quiet operation. Slowing the rotor in flight is the key to this game-changing technology. Operating at 1/3 the usual rpm reduces rotor drag by over a factor of 5. This translates to overall fuel efficiencies that have been validated through flight testing that are 2.5 – 3 times better than today’s worldwide rotorcraft fleet.
Not much to see on the Jaunt website.