[michael_miller]

To me, this is really cool, since presumably it means the materials have gotten light enough for an electric helicopter to become a reality (beyond the crappy Firefly project). Imagine what it would be like if you could commute from the suburbs of NY to the downtown heliport without paying for fuel or expensive maintenance. It could transform the way people commute to work, eliminating traffic and the effect of accidents.

[pavel_lishin]

> It could transform the way people commute to work, eliminating traffic and the effect of accidents.

Hopefully, the same people who are causing the accidents in cars won't be able to directly control the helicopter.

A car wreck slowing traffic down to 10% on a freeway is preferable to death looming from the sky because someone really needs to check twitter right now.

[glhaynes]

I'd wager that on the evolutionary path to personal aircraft, the development of self-driving cars is as necessary a step as the development of manually-driven cars and manually-piloted aircraft. Or to say it a different way: there'll never be widespread manually-piloted consumer aircraft.

[ChuckMcM]

This is the ultimate reason for not having flying vehicles. You lose one and it's injury and death all the way down.

That said, gyro-copters have excellent fail safe properties (then can autorotate/glide to a landing without power) when controlled by someone, or something, committed to operating them safely.

[starpilot]

The FAA requires that all helicopters be capable of autorotation. We actually design and test for this extensively, by adding mass to the blade tips to store inertia, pilots regularly practicing power-off flight etc.

Autogyros fly in constant autorotation (hence the name), the main rotor being unpowered.

[lmm]

It's a lot easier to avoid hitting anything in the air, because there's a lot more space up there, and a lot more directions in which to dodge. During the war we sent teenagers with <20 hours of training to fly in combat (and while many of them died it wasn't because they were crashing into each other or the ground).

[nknighthb]

It's not so simple. A worst-case scenario for a flying car might be nose-down terminal velocity into a crowded building. Or even faster, if the driver were deliberately accelerating into the building, trying to use the car as a kinetic weapon.

Scheduled commercial airline flights are quite safe, which makes people think "flying is safe", but general aviation, which lacks many of the strong controls that scheduled airlines have, is much worse[1]. I would expect flying cars under manual control of typical drivers over a crowded city to be much, much worse still.

[1] http://www.ntsb.gov/news/2012/120427.html

[pavel_lishin]

While that's true, there weren't a lot of cars on the road to hit during that time, either.

Imagine the commuting public of the New York City region, all in the air above Manhattan.

[msandford]

Low power only works with incredibly large wings/blades. So large as to be highly impractical. The smaller your blades get the worse your efficiency. That means you need more batteries. But that adds more weight and means you need a bigger motor, which requires bigger batteries and so on.

I don't think we'll be seeing electric helicopters with any practicality until battery tech gets much, much better. I can't really even think about possibilities unless it gets at least 5x better with 10x being more interesting.

[marvin]

Things get a lot better when you do a ducted fan approach, preferably with variable geometry and/or counter-rotating rotors. Electrical engines also have the advantage of being more maneuverable, which means that creating an Osprey-like design with both VTOL and flight with wings will be mechanically much simpler. You need wings to have efficient forward flight, and I think a design like this will not be practical until we use a purely electrical design.

[markvdb]

e-volo.com

[CodeMage]

I don't know much about cars or helicopters, so I have an honest question: why would the maintenance for an electric helicopter be less expensive than the maintenance for an electric car?

[msandford]

The big money saver would be the engines. Most big helicopters run on turbines and they are not cheap. And they have a limited lifetime before you're legally required to overhaul or replace them. For the engines on business jets that a friend of mine used to charter pilot, that number was between $500 and $1500 per hour.

If you built electric motors for a chopper you could theoretically design so that it had 8 motor any one or two or three of which could fail and still fly. Make several different independent battery packs and you enjoy more robustness. If you engineered it right you could make the case to the FAA that the helicopter doesn't need any expensive preventative maintenance on the motors or batteries, just on the drivetrain. Which would save a lot of money.

EDIT: "most helicopters" to "most big helicopters"

[michael_miller]

Sorry, I should have been more clear - I meant the maintinence would be inexpensive compared to a gasoline piston helicopter. Given the requirement for safety in aviation, piston engines have to be inspected (and rebuilt, at a cost of ~$50k) every ~2000 hours the aircraft is flown. This cost essentially goes away with an electric engine, partially because they last 10x as long, and partially because they cost significantly less than a piston engine.

[jlgreco]

My inclination is more expensive. You'd probably have to deal with more vibration causing more mechanical wear, and tolerances would have to be might tighter since the stakes would be higher. On the plus side you'd have less road-wear related issues, but many (probably most) car owners are able to neglect those things for years.

Nobody literally goes over a pre-drive checklist before driving down to the grocery store.

[vmarsy]

Where would you get the electricity from ?

Batteries are pretty heavy, Solar panels might be too.

[ramchip]

What about parking? How could the heliport handle massive traffic while in the middle of a huge city?