Ask HN: What are you working on (August 2024)?

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.

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.

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.

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

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!

I highly recommend a youtube channel (think hacksmith industries style) and showing how you are experimenting!

That’s what I was thinking of, yes. S3 was a huge source of inspiration for me. And Hill Helicopters with their updates and AMAs.