[IliaLitviak]

We are building a hybrid aircraft to connect cities with high speed door-to-door transportation, without train/airport infrastructure.

It’s a powered 55-seater auto gyro - an electric helicopter during take-off and landing and a conventional turboprop regional “plane” during flight. We are at a “works on paper, let’s start prototyping” phase: basic assumptions are verified by people from industry, a development plan is in place.

My co-founder is an experienced high-power electric propulsion engineer and he’s currently developing our power train. I am in charge of the business/operations/relationships side. We are currently looking for a third co-founder to lead aircraft design.

[withinboredom]

> an electric helicopter during take-off and landing

Surely this would make it significantly heavier? Wouldn't traditional fuel do better in terms of weight (and reliability)?

> high speed door-to-door transportation, without train/airport infrastructure.

Is this meant for rural transport? Looking around my urban landscape, there isn't really a place to land something like this.

[IliaLitviak]

When thinking about take-off/landing you have to take into account the powertrain, fuel, noise, power-to-weight ratio e.t.c. With modern electric motors, batteries, BMS’ e.t.c. we are at a point where system weight is comparable (the battery is relatively small, motors are quite light and powerful), but all the other things - noise, efficiency, time between overhauls e.t.c. is much-much better.

Long-term vision is to build-out a network connecting large metropolitan centers to smaller places, unlocking swaths of real estate. You can live in Albany and fly to Manhattan/Boston/Syracuse in 30 minutes whenever you need to report to office/go to a concert/visit a non-emergency doctor’s appointment. Vertiport can be located on a floating pier, on the roof of an existing transportation hub, on a plot adjacent to a bus/tram terminal e.t.c.

[withinboredom]

I've spent many hours under helicopter blades and can assure you that most of the sound comes from the blades, not the engines, when landing, hovering, and taking off. Also, there is going to be a point where you have to transition from an electric powertrain to a fuel powertrain and that handoff has to be absolutely perfect while hundreds of meters in the air. (Think grinding gears in a manual transmission car.) You could do something like a liquid clutch or something, but that is one more thing to fail and introduces inefficiencies. It is honestly probably better to go with traditional jet engine technology, at least at first, to verify the business model. Then, spend some time innovating.

I'm willing to bet that innovation in blade design will get you much further than innovation on the power train itself.

[IliaLitviak]

The beautiful part is that our powertrains are completely separate. You fly up/down using rotor. You fly forward using turboprop. The only transition that occurs is change in pitch of rotor blades to go from “powered” state into “passive autogyro” state. No complex clutches, no rotating mounts (like on Osprey). Completely separate independent systems. It also provides some measure of redundancy.

You are right that most of the noise comes from blades. And yes, there is some awesome blade design progress, especially for auto-gyros. Also there are a lot of specific things like low rotational speed, lack of tilt and other stuff that plays well into less noise in our specific application. But no, we won’t be as quiet as multicopters, especially those with ducted fans. That’s ok, this is a reasonable trade-off - manageable noise levels, a lot less complexity, lots of lift.

[withinboredom]

Sounds interesting! Do you have a blog or website to follow progress?

[IliaLitviak]

Not yet, we are a bit too early for that! But I sure hope that we’ll be able to start actually building soon, and then we’ll be very much doing that in public. It’s companies like Astranis, Boom and Hill Helicopters who inspired us and we’d love to follow their lead!

[lpfeifer]

Great concept. Where can I find more info?

And out of curiosity, how did you decide on 55 seats?

[IliaLitviak]

We are far from public yet, but you DM me on LinkedIn, I’m always open for a chat!

It’s a sweet spot. Large enough to be useful, small enough to have reasonable refuelling times.

[lpfeifer]

Thanks, I will look out for more updates here on HN.

This kind of vehicle has fascinated me for years. Seems like they'll be the transportation mode of the future, and that fully self-driving commuter aircraft will come before their ground-based counterparts, since the sky is a much simpler realm than the ground. The main challenge seems to be safety / reliability. Turbulence dampening, emergency landing in a variety of terrain, automatic ground-obstacle avoidance and communication with other aircraft (and that requires near-perfect cybersecurity).

Exciting times.

[IliaLitviak]

We are obviously thinking about that. VTOL capability makes our aircraft a bit more safe - it can literally land anywhere but water. And there’s probably a way to make it float two. But! Air is not an easier environment, it’s just different. With lot’s of limitation, both natural and regulation. My good friend is developing an automation suite for small aircraft and he’s dampened my optimism significantly! But still, It is the way to go, it’s just not as easy as it might seem.