The Airbus Vahana was an electric-powered eight-propeller VTOLpersonal air vehicleprototype financed by Acubed, by Airbus and Airbus Urban Mobility. The Vahana project started in 2016 as one of the first projects at Acubed, the advanced projects and partnerships outpost of Airbus Group in Silicon Valley. Airbus "envision Vahana being used by everyday commuters as a cost-comparable replacement for short-range urban transportation like cars or trains". It was planned to be a part of urban air mobility. The project was finished in December 2019.
Development
The convertible aircraft design, funded by the European aircraft manufacturer Airbus, called Vahana, started in 2016. It was being developed at Acubed, the expanded project and partnership outpost of Airbus in Silicon Valley. Airbus said "Our work on this demonstrator confirms our belief that fully autonomous vehicles will allow us to achieve the scale required of Urban Air Mobility."To test the Vahana concept, small models flew in Santa Clara, USA in 2017. Acubed Vahana was planned to become part of urban air mobility. In June 2017 at the Paris Air Show the prototype Vahana Alpha One was publicly presented for the first time. 31 January 2018 the first flight took place in Pendleton. The full-scale aircraft Alpha demonstrator reached a height of 5 meters within 53 seconds. By August 2018, more than 25 hover flights had been completed and the transition to forward flight had been tested. Airbus finished the Vahana project in December 2019 in favor of the CityAirbus. The last flight took place on 14 November 2019. 138 test flights with a total flight time of over 13 hours and a distance of 903 km were made. By January 2019, the second aircraft, Alpha 2, was completed, while the first was testing transitions to forward flight, but was not yet flown with the wings horizontal. On 3 May, it achieved its first full transitions to forward flight, reaching on its 58th flight. Airbus will not produce serial versions of the Vahana or the ducted-rotor CityAirbus demonstrators. The last of 138 test flights took place on 14 November 2019. The test flights had a total flight time of over 13 hours and a distance of 900 km flight.
Design
Cconfigurations include electric helicopter and eight fan tilt-wing. For both configurations the hover performance estimates were based on blade element momentum theory. Vahana found the electric helicopter configuration superior at low ranges, and the tilt-wing configuration superior at longer ranges. The designer has not finalized the Vahana project and hope that "the electric tilt-wing configuration provides a DOC advantage and many other advantages such as reduced noise and enhanced safety for urban mobility". For both vehicles a common payload weight will be 200 lb. A helicopter gearboxpower density is assumed to be 6.3 kW/kg. Both configuration will assume 15 kg for avionics components and 15 kg for a crash rated seat. electrical actuators will take 0.65 kg each. Additionally, the tilt-wing has two actuators. An additional 10% is for fittings and miscellaneous hardware. The cruise power of the tilt-wing is lower than the cruise power of an electric helicopter. The disk loading for both configurations is similar to those of many existing light helicopters. The electric helicopter hover power at short ranges is lower than those of the tilt-wing. One of the reasons why Acubed Vahana was being developed as a self-steering aircraft was because the developers expected the available human pilots would not be sufficient in number for the anticipated volume of flights. Another reason was the higher payload and saving on labour expenses. In contrast to autonomous driving, autonomous flying has to be navigated at a significantly higher speed and in three instead of two dimensions. This requires higher computing speed and faster sensors and actuators. Autonomous navigation is carried out with a Lidar system, together with cameras and radar.
