Safe and agile Electric VTOL concept for mass transit and military use

I created this concept to fix the **huge** design problems in many "E-VTOL" concepts in the "Uber Elevate" Summit. Many of the concepts have high rotor disc loading operating at low Reynolds Number which could severely compromise safety (Aviation experts, pls read below).

High disc loading + Low Reynolds Number would make the rotor blade operate much closer to stall angle.

Operating close to stall angle is **NOT** a safe way to fly as there are many things that can cause the rotors to reach and exceed stall angle such as approaching fast, meeting updrafts or getting out of downdrafts, turbulence, etc. And there are plenty of these in cities, around buildings and obstacles in windy conditions.

Grounding the whole fleet because of some wind in the city? Operators and customers won't be happy. Or a fatal crash due to unexpected gust of wind? It could kill the entire program!

High disc loading also requires **A LOT** more power to hover than low disc loading. Even worse, the closer-to-stall operation, and low Reynolds # further deteriorates propulsive efficiency. They would eat up a lot of energy from the battery during vertical and low speed flight.

The consequences of all these is that landing approaches must be done very slowly to avoid stalling the blades. So if there are multiple such vehicles approaching -very slowly- at the same Landing Zone (LZ), some of the vehicles would likely run out of battery before even reaching LZ....OR....Traffic control would delay subsequent flights until one LZ is cleared which somehow defeats the purpose of this program which is to speed up transit.

The solution is to achieve a low disc loading design that uses variable pitch control to afford a large safety margin before stall conditions are approached. All helicopters use this design practice which makes them highly successful among VTOLs.

The design practice also allows many helicopters to operate safely even in adverse weather conditions.

"Auto-rotation" approaches can also be executed which doesn't use any power at all and would allow fast landing approach that could prevent congestion in LZs.

I've used the X-Plane 10.51 flight simulator which is often used in flight research to highlight the huge advantages of designing low disc loading together with variable pitch rotor controls.

Keeping costs low can only be done up to a point until safety is compromised. Compromising safety is always a terrible design practice. Terrible, terrible!

Some could argue if it keeps flying within the flight envelope, such risks are avoided.... But the much smaller flight envelope of high disc loading designs leaves a much smaller margin for error as well. They will be grounded in weather conditions were low disc loading, variable pitch designs (like helicopters) can still fly safely.

Music used in the video: Faster Than Light by Extan.

Видео Safe and agile Electric VTOL concept for mass transit and military use канала Supersafe Aerodynamics