Emerging UAM Design Trends

This has been a huge year for flying cars. With the Bell Nexus recently revealed at CES, and the Boeing PAV making its first flight in this last month alone, the time of urban aviation is nearing.

Over the last few years, a few designs have emerged as the most common. These are illustrated by the EHANG 184, the Boeing PAV, and the Bell Nexus.

Type 1:  “Passenger Drones”

While most air vehicles will eventually have full autonomy, there is a category of eVTOL that stands out as looking particularly like large versions of recreational consumer drones. These are what many people think of at the phrase “Passenger Drones”: 

TheEHANG 184 (left) and Workhorse SureFly (right) and are examples of the ‘Passenger Drone’ design. Both have eight rotors; four on each stem.

These eVTOLs are recognizable by their lack of a fixed wing. Generally, as well, they tend to have lower top speeds and ranges than other more complex designs. However, they are extremely favorable because of their compact size and ability to be fully electric. Other similar designs include the Vertical Aerospace eVTOL and Volocopter 2X, which is set to begin testing in Singapore this year.

 

Type 2: Tilt-Wing/Rotor

These eVTOLs feature a wing as in traditional airplanes. These wings give them extra-lift during flight in order to increase range and efficiency. In many eVTOL designs, the propellers are built onto the wing itself, which tilts to face vertically for take-off and then tilts to a traditional horizontal wing position for cruising flight. Or Alternatively, the wing will stay fixed while only the rotors tilt, as seen in the Bell Nexus.

The Bell Nexus (left) and the MOBi-ONE (right) are examples of Tilt-Wing and Tilt-Rotor eVTOLs

Other tilt wing/rotor designs include Transcend Air Vy400, Dufour Aerospace’s aEro2, the Joby S4, the JETCopter, and the Lilium Jet (these last two feature jets rather than rotors).

 

Type 3: Multi-Position Fixed Rotor

This type first surfaced with the Larry Page backed Kittyhawk Cora. Then earlier this week, Boeing completed a successful Test flight of its Passenger Air Vehicle, which features the same design.

The design is fairly simple: Two parallel bars on which there are multiple vertical-facing rotors, along with one larger rotor at the back for horizontal flight. This design allows vertical and horizontal flight on a fixed wing without any tilting of wings or rotors necessary.

Boeing Passenger Air Vehicle (left) and Kittyhawk Cora (right) both feature a horizontal propulsion rotor at their rears.

One other aircraft that features the multi-position fixed rotor design comes from UberAir. Although this aircraft is only a concept with no prototyping plans, Uber Elevate is working closely with both Bell and Uber on UberAir.

Why it’s important: All the existing eVTOL designs have benefits and drawbacks and are likely to be used in different capacities, areas, and industries. Over time and with testing, it will likely become more and more clear which eVTOL designs should be used where.