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Comment by phkahler | Hacker News Reader

Forget electric. That's just a gimmick that allows these companies to say "in five to ten years because batteries." Prove it. Make a gas powered one to prove your concept. The simplest flying machine is probably an autogyro. Automate that for point to point transport, show the automation, redundancy, and safety for urban use. Solve those real issues and then we can talk about fancy designs.

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Electric is a game changer for popular aviation. Why? Because aviation has (fortunately) very strict safety standards. So the aviation version of common car engines are vastly more expensive than their car counterparts. They also require expensive maintenance regularly. Electric engines are mostly maintenance-free, and the biggest point is, you can have any number of electrical engines on your aircraft - the common drone has 4 independent engines, and people-carrying crafts can have 10 or more, basically eliminating any reliability related safety concerns.

People put common car engines on aircraft all the time. The problem is that "certified" aircraft engines are expensive due to that designation (think regulatory capture). There are several cheap auto-engine options for homebuilts. Maintenance can be done by the builder for homebuilts too. The costs are almost completely due to the small market size.

I agree with you that electric motors are awesome (they're what I do) and you're right that you can easily put 2-4 of them on a fairly conventional aircraft for amazing redundancy.

The problem with the quad-rotor configuration is that the motors are doing all the work. With real wings you get a better lift to power ratio but you also lose VTOL capability.

Having said all that, I'd still like to see a small short field aircraft automated to the point that the general public could use it.

>You lose VTOL

Joby and Zee are using wings plus VTOL. They shut down the VTOL rotors for level flight.

That could actually be awesome. Use electric motors in a drone type configuration for VTOL and then just use a gas engine for cruising.

How is an autogyro simpler than a fixed wing aircraft? The both have a motor, and on one of them the wings have to move.

Lower stall speed

>> How is an autogyro simpler than a fixed wing aircraft?

https://www.youtube.com/watch?v=lhZJgOA-hyI

https://www.youtube.com/watch?v=ohGAQfseJzM

Sure looks simpler. You also get short field takeoff and vertical landing.

How about a roadable one: https://www.youtube.com/watch?v=CajAq6ndJYE

From the article:

"This kind of design wouldn’t work with conventional aircraft engines because 10 engines would be way too heavy. But electric motors can be made extremely small and light, allowing even a car-size vehicle to have 10 of them."

But batteries are a significant source of weight.

Look, you can't simply build a mini-plane with 10 combustion engines. It's a design you can't bootstrap powered with gas and migrate to electrical later.

You also can't put combustion engines in the end of small actuators, like it's on the article.

10 is overkill. You might try two: https://www.youtube.com/watch?v=knb3qNq-Uho

The benefit of electric is the ability to very quickly alter thrust for that quad-rotor type of control.

Gas requires fuel and exhaust pipes, and is only efficient at some engine sizes. Electric, you can hang anywhere on the airframe, at many sizes. It's quiet, requires for urban VTOL. Distributed propulsion also lets you run props out of phase for noise canceling.

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