The amount of energy required to keep something in the air instead of using the ground is also astronomically bigger
Comment on Amazon's drone delivery program is the joke it always sounded like.
SlopppyEngineer@discuss.tchncs.de 7 months agoThat’s not the only reason why flying cars haven’t arrived. Getting a license to fly is about the price of a new car. Bad weather is no flying. Air Traffic Control can’t handle thousands of commuters. Flying cars are pretty big so parking is going to be even more of an issue.
Honytawk@lemmy.zip 7 months ago
merc@sh.itjust.works 7 months ago
Not really. Many planes can get about 20 miles per gallon traveling at about 180 miles per hour. That’s slightly more than a family car, but not astronomically more.
The big differences are that there’s effectively no “traffic” in the air, so once you dial in a cruise speed you stay at that speed for the entire flight. In a car you can get stuck in stop-and-go traffic. There’s also the lack of “rolling resistance” in the air. Even if you’re going a steady speed on a highway your tires are a source of drag. On the other hand, taxing and taking off can burn gallons of fuel, so unless you’re going for a fairly long flight that’s a significant part of the fuel burn. Also, planes go in a straight line, whereas cars have to follow highways. But, the total fuel cost of the trip really includes the trip to/from the airports.
But, fundamentally, the fuel economy of cars and airplanes is pretty similar.
Dicska@lemmy.world 7 months ago
Also, imagine drunk flyers in bad weather.
Ground traffic collisions can also cause collateral damage, but more often than not those are constrained to the roads or their immediate vicinity where not many people live. An aerial collision may happen above residential areas, and even slight fender benders may mean a double crash (…on little Timmy mowing the lawn).
Also, there’s no air bag in the world that can save you in a crash.
Road traffic is easy to direct and regulate with road signs, lanes, lights, painted lines. Good luck herding cats a hundred (hundreds of) yards above ground. It’s not a huge problem with planes because there are not as many of them and they fly at vastly different altitudes. Not the case with personal flying cars.
With ground traffic, you only need two blinkers (or two sets). Some drivers even struggle with using that two properly. Good luck for getting them to use more.
And that’s just the top of my head, I’m sure there are like 2634 other reasons.
merc@sh.itjust.works 7 months ago
I can’t imagine an “open to the general public” flying car system that didn’t involve huge amounts of automation, basically self-flying planes. A modern jet liner is effectively self-flying already. And, even though the pilots are rarely required to take direct control over the jets the alcohol limit is 0% and they’re not even allowed to drink within 8 hours of a flight. So, to have a scenario with “drunk flyers in bad weather” you’d need a system with looser rules than current aviation, and less automation that current aviation.
No, but there are parachutes.
Besides, most fiction involving flying cars also involves automated flying cars. Sure, often the “hero” takes direct control of the car and does some crazy maneuvers with it, but in the futures where flying cars exist, autopilots are extremely advanced, and most commuters just hit the button and relax. In addition, if an autopilot did exist, it could become “driver assist” if the human decides to take “direct control”. So, even in a future with frustrated aerial commuters who get “sky rage” and decide to take over flying from the autopilot, a “pilot assist” program could still interpret what they want and limit the danger they pose to themselves or other craft.
The F-16 is almost 50 years old now, and for those 50 years it has been impossible for pilots to fly it with “assists off”. The plane was designed from the start to be dynamically unstable. A pilot simply couldn’t control it without computer assistance. The pilot uses a fly-by-wire system where their inputs are interpreted by computers that do the right thing while still maintaining stability and so-on. A future flying car would pretty obviously be designed the same way.
Dicska@lemmy.world 7 months ago
Yeah, as I was writing that, I was thinking about '80s flying car lanes. It’s like a flow of cars with constant speed. But the ‘drunk flyers’ bit meant that we are humans. You’re also not allowed to drive drunk on the roads. That doesn’t prevent people from still doing that.
Good that you’ve mentioned the F-16, I’m just watching a video on them by Real Engineering on YouTube. I can only recommend the channel, and I’m not even an engineering nerd. Well, not yet.
merc@sh.itjust.works 7 months ago
I haven’t watched a video on the F-16 for ages. I am just an aviation fan and have heard many stories of the F-16 over the years.
I don’t know if it’s mentioned in that video, but the early days of the F-16 were really interesting. It was the first ever fly-by-wire fighter, so there were lots of design issues to work out. The very first versions of the F-16 (maybe still the YF-16 at that stage) used a side-stick that didn’t move at all, it was designed to be pressure-sensitive so pilots could pull lightly to put a little bit of elevator pressure on, or pull hard to go to the elevators’ max deflection. The problem was that pilots never knew when they had reached the limits, so they pushed as hard as they could on the stick. Observers said that you could actually see a twitch in the control surfaces when pilots were at the max, and the twitch was due to being able to see the pulse of the pilot.
After a short time, General Dynamics switched to a side stick that had some range of motion, so that pilots knew when they were at the limits of the controls and didn’t keep pushing.
SlopppyEngineer@discuss.tchncs.de 7 months ago
They’re working on next generation air traffic control, that is automated and also can handle drones whizzing around next to flying cars, but developing that isn’t fast or cheap or deploy and will need extra equipment on the ground and in the cockpit.
Dicska@lemmy.world 7 months ago
…and that’s still just for the drones.