The Case For The Round Wing

The ZEVA ZERO is clearly a unique vehicle. The media has even differentiated ZEVA from the rest of the eVTOL crowd by referring to it as a UFO or a flying saucer. Wondering why we chose the round wing design for our aircraft?

When Team ZEVA set out to design the ZERO, we knew we needed to solve two big problems:

1. generating enough lift to give the aircraft a 50 mile range while staying compact enough to land anywhere
2. maintaining stability while transitioning from hover to cruise.

While researching many possible configurations, the round wing became the clear choice. While this compact shape looks quite different from other eVTOL in the industry, we found data from early aerospace pioneers that explored the benefits of this design.

In 1934, the Nemeth Parasol was created.

Then in 1941, the Vought V173 or “Flying Flapjack” was built and flown.

These aircraft proved that a round wing was a viable option. The Flapjack also proved that the wing-tip-vortices, or the rotating air around the wing as it generates lift, could be partially nulled by using counter rotating propellers at the front of the wing. Importantly, these early innovators learned that the round wing has a very high angle-of-attack stall angle of about 30 degrees. When applied to ZERO, this aerodynamic characteristic provides a wide flight envelope and facilitates transition between hover and cruise modes.

In 2017, we began building ZERO based on the requirements of the Boeing sponsored GoFly Prize. The rules of this program required the vehicle to fit within a maximum extent of 8.5 feet in the largest configuration. The team wanted to maximize the amount of lift in that volume, and thus, selected the round wing for this purpose.

The round wing supports the design goal of a compact flying machine that can easily coexist with current infrastructure off-airport. And this is why it was selected for ZERO.

Learn more about ZEVA ZERO and how you can invest in the future of personal flight here.