Milestone coming up for Vahana prototype

By Tom Risen|June 28, 2018

Transitioning from vertical to full speed horizontal flight has snagged past aircraft designs.

AIAA AVIATION Forum, Atlanta — August won’t be a sleepy month for A3, the Silicon Valley arm of Airbus that plans to build a fleet of single-passenger, automated aircraft called Vahanas.

If all goes as planned, the company will for the first time transition a full-scale prototype of the aircraft from vertical to horizontal flight. The prototype, called Alpha One, will do this by tilting its wings, which have electrically driven propellers distributed across them.

A3 (pronounced A cubed) is among at least a dozen companies vying to create eVTOL (electric vertical takeoff and landing) aircraft as a new way to get around a city or from downtown to the suburbs or vice versa.

The company started flight tests with Alpha One in January at the company’s site in Pendleton, Oregon. So far, the company has flown a subscale model through the transition.

A3 envisions Vahanas being available to fly passengers around a city or from downtown to the suburbs as early as 2022, but the exact timing depends on flight testing and certification for safety, the company’s CEO Rodin Lyasoff told me.

Accelerating Alpha One to full speed after the transition will test the aircraft’s safety and efficiency, he said.

A3 is confident in the transition because of distributed electric propulsion and because of the subscale flights. Lyasoff said the subscale version “was very stable and well behaved throughout the transition.”

The prototype will attempt to transition from vertical flight by tilting its wings forward, which Lyasoff told me is a design chosen to give the aircraft “relatively simple aerodynamics and ease of handling.”

EVTOLs rely on wires and have relatively few moving parts, noted Greg Bowles, who manages the Electric Propulsion Innovation Committee at the General Aviation Manufacturers Association.

“I think we are seeing a lot of vehicles having success doing transitions, it has definitely been a learning curve for a while,” said Bowles, who previously worked as a certification engineer at Keystone Helicopter, which is now part of Lockheed Martin-owned Sikorsky Aircraft. “The question is no longer can I transition, which was historically the question, but instead can I transition in a way that is energy efficient and quiet, or in a way that can withstand the failure of a propeller and still land safely.”

The A3 photo shows a Vahana at the company’s test flight site in Pendleton, Oregon, where test flights began in January.