Do we actually want flying cars? They are probably less efficient because you have to overcome gravity, they are probably going to be pretty noisy, falling out of the sky and smashing into the ground is a new failure mode, ... Flying cars are certainly a nice gadget, but do we really need or want them? I can only think of two good arguments for flying cars, entering the third dimension if we run out of space on the s…
Let's build a bot to participate in HN discussions. Then we can all save some time and get back to work. My first two suggestions: Q: Someone is building flying cars. A: Do we really need them? Q: Someone is investing money into extending human life. A: Let's talk about the social implications of immortality.
Larry Page is pouring millions into flying cars
151–160 of 242 posts
Re: Larry Page is pouring millions into flying cars
#152Earlier quoted context omitted.
Biofuels. Otherwise, you're waiting another 20 years.
to do a small combustion engine VTOL vehicle its even harder I have only seen it work with several two stroke engines. Another optin is turbine like the AirMule, but will be hard to use it for civilian operations the hourly cost is brutal and noise and heat is really annoying for nearby people and even passengers. https://en.m.wikipedia.org/wiki/Urban_Aeronautics_AirMule
http://www.dailymail.co.uk/news/article-2123200/The-ultimate...
Re: Larry Page is pouring millions into flying cars
#153Re: Larry Page is pouring millions into flying cars
#154Interesting title considering the article's as much about Uber and battery efficiency a la Tesla as it is Larry Page. I'm still curious about how highways for these types of aircraft will be implemented. I imagine the goal is ubiquity and at some point, with thousands of these things flying around, flight paths will be the bottleneck.
could be VTOL http://moller.com/ - this project seems dead =( hopefully either I'm wrong or something more interesting takes its place
Re: Larry Page is pouring millions into flying cars
#155Earlier quoted context omitted.
I have been working on a flying car project for years and can guarantee you that one/two seat Electrical VTOL is at least 30 years away, battery density must triple and then you have regulations. Current solutions can be airborne at maximum 15 minutes considering that FAA and other agencies require 20 minutes reserve you do the math. The Zee.aero patent design as been abandoned because they couldn't scale it to fit a…
If by "flying car" Larry really means "Toyota Camry that can fly with middle class people inside" then that's obviously preposterous to anyone with the slightest shred of general aviation experience. If he means "VTOL Cessna with really good avionics" it's still a tall order but perhaps within the realm of "eventually possible given great determination and unlimited money" instead of "laugh him out of town."
As a proxy you have Icon A5 it was target at a price point of $130k in 2008 currently it's priced around $240k and only a handful have been delivered.
Re: Larry Page is pouring millions into flying cars
#156Earlier quoted context omitted.
I have been working on a flying car project for years and can guarantee you that one/two seat Electrical VTOL is at least 30 years away, battery density must triple and then you have regulations. Current solutions can be airborne at maximum 15 minutes considering that FAA and other agencies require 20 minutes reserve you do the math. The Zee.aero patent design as been abandoned because they couldn't scale it to fit a…
what about the joby s2? Is that also impossible? It looks feasible and there are a bunch of people working on it... Thoughts?
Re: Larry Page is pouring millions into flying cars
#157Do we actually want flying cars? They are probably less efficient because you have to overcome gravity, they are probably going to be pretty noisy, falling out of the sky and smashing into the ground is a new failure mode, ... Flying cars are certainly a nice gadget, but do we really need or want them? I can only think of two good arguments for flying cars, entering the third dimension if we run out of space on the s…
The rolling resistance of a typical car is 0.01 to 0.015 [1], so the effective lift/drag ratio of a car's suspension is about 70 to 100, for just the wheels themselves. Missing from this number are the parasitic losses of all other unsprung mass, aerodynamic drag, and the costs incurred by traveling along roads which are neither level nor straight routes between your start and your end.
Small aircraft have L/D of 10-20 [2], and electric craft will probably fare slightly better if anything because of packaging advantages vs big ICEs.
I might do a more in depth analysis later and write up a Medium post, but my point is: Even just looking at the rolling resistance of the car and the whole L/D of aircraft, the difference is only an order of magnitude. Rolling resistance is one of the smallest contributions to drag in a car, so all up electric cars are probably only 3-6x more efficient than electric aircraft, and combustion cars are probably have a far smaller advantage.
[1]: https://en.wikipedia.org/wiki/Rolling_resistance#Rolling_res...
[2]: https://en.wikipedia.org/wiki/Lift-to-drag_ratio#Examples
Re: Larry Page is pouring millions into flying cars
#158Earlier quoted context omitted.
what about the joby s2? Is that also impossible? It looks feasible and there are a bunch of people working on it... Thoughts?
For electrical VTOL the Joby is probably the best bet, one big question mark is, the 16 motors how much will weight even at a very low weight of 15kg each you get 240kg/52lb in motors a similar complete two person glider weights around 300kg/661lb.
Batteries are the heavy bit, and in my opinion, the future there is to have batteries capable of 2 minutes of flying, and a gasoline engine as a hybrid generator.
Re: Larry Page is pouring millions into flying cars
#159Earlier quoted context omitted.
> The views! Obviously, these will be blocked by swarms of flying cars.
Long after they're blocked by swarms of delivery drones.
Re: Larry Page is pouring millions into flying cars
#160Earlier quoted context omitted.
Self flying aircraft are much easier than cars. Fewer variables and years of experience in military contexts. My parents live in a rural area 16 mikes from our city center. Due to terrain and roads, it's a 30 mile/60 minute trip. With a flying car/shuttle, its no more than 20 minutes.
I'm going to infer you're talking about drones. There is a quantum leap difference between self flying military robots, and ones that carry humans around safely during rush hour crowds.
What would the average person say about a self-driving cab that is currently being piloted by Uber at that time?
I'm honestly surprised about the downvoting and snark here. There are Air Force officers sitting in trailers in Nevada right now controlling swarms of semi-autonomous drones, performance surveillance and blowing stuff up. Why is a simple air taxi beyond the imagination?