Comment by jillesvangurp | Hacker News Reader

Comment by jillesvangurp | Hacker News Reader

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Rotor size matters a lot for noise and how far it carries. Compared to a helicopter these things are going to be a lot less noisy. Also there's a difference between landing/taking off and cruise. Several of these designs have wings and a vtol configuration. There's no shortage of roof tops, open areas, etc. that could be converted to land on. As soon as viable products hit the market they'll be very popular. Finally, cities are noisy places and it will be hard to hear them over the background noise.

The reason this will take off (physically and economically) is cost. If you can travel 40-50m quickly for about the energy cost of a cup of coffee, it's going to be a game changer in big cities. I can take an Uber across town in Berlin but it will cost me around 20-30 euros and take 50 minutes (worse in rush hour) and is not that competitive with public transport. The same journey with a flying taxi could be done in 5-10 minutes (just like with a helicopter) the difference will be vastly lower cost. The main cost will be the pilot who can now do multiple journeys per hour and at least short term still charge a premium.

Even if this will be economically viable, the regulations around it could be so harsh that the idea could not take off.

There have to be rules where those taxis can start, land, in what direction, time frames and over which places in a city. You need some kind of air control and "traffic rules". Drivers need regulated training in simulators and there need to be emergency procedures.

I believe that in the first few years such things won't be allowed near towns and cities. There will be similar rules like flying drones [1], but a lot stricter.

And the time saved by such travel will probably decrease when the sky starts looking like in the 5th Element [2].

[1] https://uavcoach.com/drone-laws-in-switzerland/ [2] https://media.giphy.com/media/Bs2pZhpxf2168/giphy.gif

Initially yes. But the way this starts snowballing is some cities showing they are cooler than others by allowing these things and demonstrating it is fine. Then envy will force the issue and regulation will catch up in most places. IMHO autonomous flight will be the drive this. By the time regulation catches up, having a pilot on board is not going to be a thing any more. Also practically speaking, training that many pilots is just not going to happen in time for that to matter. E.g. deploying 10K of these things would require as many pilots (at least) and they simply don't exist right now. Going from a few hundred to a few thousand will happen relatively quickly but from there to e.g. a few hundred K won't happen until autonomous flight is ready to scale. IMHO we're looking at 15-30 years here for this to happen. With autonomous prototypes flying today, that's a conservative estimate. IMHO the biggest bottleneck will indeed be legal & regulations.

Short term, these things will mean helicopters that currently service rooftops in many cities will be replaced by slightly more of these things flown by professional pilots that will have increasingly less to do as these things start flying themselves. I also expect an increase in heliports. E.g. Manhattan only has a few right now.

I don't see anything fundamentally different than when automobile travel was new. Yes, there will be rules and training, etc. That does not preclude the possibility of having cheap and efficient air travel.

How would this differ from existing regulations for helicopters?

> travel 40-50m quickly for about the energy cost of a cup of coffee

By "energy cost" do you mean something like "the price of a cup of coffee spent on electricity"? That seems surprisingly efficient but maybe here (Europe) the coffee is cheaper and the electricity dearer - what's the figure in kWh?

Around 20-40 kwh or so for a single journey assuming a maximum capacity of 100-150kwh and assuming it would be rare to use more than 20-30% of it on a single journey or fly the maximum range. At 5-10 cents per kwh (i.e. 20-40kwh/$) we're not even talking some fancy barista doing their thing. Grid prices can be higher of course but I'm assuming a bulk consumer of energy would invest in turning this in a fixed cost by e.g. installing solar panels & batteries to lower the cost.

By the time these things start flying at scale, the coffee will be way more expensive than the energy cost. That's why most of these companies are investing in autonomous flight as well because short term that is going to be the cost bottleneck (that and training the army of pilots that they'd need).

So around 0.4 kWh/passenger-km? - seems it compares pretty favourably to long-haul aviation (e.g. wiuth very crude maths 600 people on A380 at max range/fuel works out as 0.36). Naively I had been assuming that the battery mass and small scale would be more punishing than that.

I think you’re going to need to make an actual argument about why the cost would be lower.

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