Uber has added a fifth electric vertical-takeoff-and-landing (eVTOL) vehicle developer to its Elevate aerial ridesharing program, announcing a partnership to develop Jaunt Air Mobility’s Reduced Rotor Operating Speed Aircraft (ROSA).

Jaunt joins existing vehicle partners Bell, Boeing subsidiary Aurora Flight Sciences, Karem Aircraft and Pipistrel. The startup acquired the rights to Carter Aviation Technologies’ slowed-rotor compound (SR/C) concept. Carter was part of a team led by Mooney that was selected by Uber in 2017 as one of its original Elevate vehicle partners but was later dropped.

The ROSA is based on the SR/C concept, which is essentially the combination of an autogyro and a compound helicopter. The rotor is spun up for vertical takeoff and landing, but is unpowered in forward flight, when lift is provided by a wing and propulsion by a pusher propeller. The rotor is slowed in flight to reduce drag while the wing increases efficiency. The lower tip speed reduces noise compared with a helicopter.

Jaunt has signed an MOU with Honeywell to define avionics, navigation, flight control, electric propulsion and connectivity systems for the ROSA. As part of the agreement, they will work together to develop the technical requirements, statement of work and definitive agreement to support Jaunt’s eVTOL demonstration by the fall of 2012.

Jaunt was named as a vehicle partner at the opening of the third Uber Elevate Summit, held in Washington, DC, June 11-12. Also at the summit, Slovenia’s Pipistrel revealed the configuration of its eVTOL aircraft, a five-seater with low-pressure electric fans housed in canoes shoulder-mounted on either side of the cabin and a pusher propeller on top of the tail for propulsion. Uber says the fans draw 50% less power in hover than traditional rotors.

EmbraerX unveiled the latest version of its eVTOL, which now has two rear-mounted ducted props for propulsion and eight rotors for lift. The rotors are mounted in fore-aft pairs on booms attached to the tips of a forward canard and rear wing. The rotors stop and align with the airflow to reduce drag in forward flight. Bell displayed the full-scale mockup of its Nexus tilting ducted-fan eVTOL.

Karem presented a refined design for its Butterfly Optimum Speed Tilt Rotor eVTOL, which has four proprotors mounted on the tips of the high wing and V tail. Boeing displayed a model of its two-seat Passenger Air Vehicle (PAV), which made its first hover flight at Aurora in January. The PAV has six lift rotors mounted on two rails below the fuselage, a wing and a pusher propeller for propulsion. A PAV prototype crashed during a flight test in early June.

Uber itself unveiled a full-scale mockup of its first air-taxi cabin design, developed with Safran Cabin’s ZEO Studio. The cabin, which seats four passengers in two rows, plus a pilot, is intended to act as common reference model for eVTOL vehicle developers.

“We had six full-scale mockups, with multiple iterations in each one, looking at the seats, liners and window positioning,” ZEO EVP Scott Savian said. Requirements include minimum weight and cost, but also safety and comfort. “So, while the cabin may be minimal in some ways, it’s absolutely purpose built to the mission,” he said.

In other agreements announced at the summit, Uber Elevate is to collaborate with AT&T to explore how 4G LTE and 5G connectivity can be used with eVTOL air taxis and cargo drones. And Elevate has selected real-estate developer Related Companies as its preferred partner for developing Skyports to support the rollout of its Uber Air network in the US.

Existing Uber Elevate property development partner Hillwood, meanwhile, has announced plans to establish the AllianceTexas Mobility Innovation Zone at Fort Worth Alliance Airport in Texas. The zone will be used to help develop standards for urban drones and air taxis. Alliance is close to Dallas, one of the launch cities where Uber Elevate plans to begin demonstrations in 2020 and commercial service in 2023.                                            

Graham Warwick, Graham.warwick@aviationweek.com