3 ms·

> There's a lot more space in the air than on land. But that's mitigated by the fact that the failure modes and much, much worse. I can drive safely at highwa

> There's a lot more space in the air than on land. But that's mitigated by the fact that the failure modes and much, much worse. I can drive safely at highway speeds with a couple hundred feet of separation between cars. FAA rules on safe separation between planes laterally is about 3 miles, or about 50 times the distance, or 2500 times the surface area. Plus planes compete with one another for access to airports, so you haven't actually solved any congestion issues -- the bottleneck is still near the ground.

paulddraper 10y ago
A 3 mile horizontal radius has little to do with flying and a lot to do with speed. At ordinary commercial airline speeds, it's the equivalent of a "20-second rule" (i.e. it's the distance covered in 20 seconds by a 500-600mph vehicle).
- cmurf 10y ago
  There is a 250KIAS speed limit below 10000'MSL that applies to everyone flying VFR including airlines. They're quickly climbing out above that and end up being a non-factor. The real issue is all the other general aviation aircraft.
- Dove 10y ago
  Just the same, cars can be driven almost bumper to bumper, at arbitrarily low speeds, in ten foot wide lanes. The realities of wind and minimum forward speed and prop wash dictate that aircraft will need a lot more clearance than a car does. I'm sure it will depend on the particular air vehicle and the rules of traffic in the sky, but I for one would have to be convinced that aircraft can give better throughput than a road can. On the face of things, I'm not sure that's the case.
cmurf 10y ago
That's for visual flight rules. There's no way this works with VFR. For one, the examples are all major cities where there's Class B airspace, requiring positive separation. So it's basically "clear of clouds", however that assumes you're cleared into Class B. There's no possible way this works with the existing ATC system. Flying cars won't use the same airspace as turbine powered airline planes, so a new airspace designation could exist just for cars. And drones. Because drones and flying cars will be competing for the same airspace so all of them will need to use the same system. Added: Flying cars (and to some degree drones) do compete with the same airspace as existing general aviation flights. And that's a big problem. The legacy aircraft would have to avoid the new airspace, most won't ever get an upgrade to fly autonomously; alternatively, the flying cars will have to be programmed such that they can always yield right of way to legacy aircraft.

paulddraper 10y ago

A 3 mile horizontal radius has little to do with flying and a lot to do with speed. At ordinary commercial airline speeds, it's the equivalent of a "20-second rule" (i.e. it's the distance covered in 20 seconds by a 500-600mph vehicle).

cmurf 10y ago
There is a 250KIAS speed limit below 10000'MSL that applies to everyone flying VFR including airlines. They're quickly climbing out above that and end up being a non-factor. The real issue is all the other general aviation aircraft.
Dove 10y ago
Just the same, cars can be driven almost bumper to bumper, at arbitrarily low speeds, in ten foot wide lanes. The realities of wind and minimum forward speed and prop wash dictate that aircraft will need a lot more clearance than a car does. I'm sure it will depend on the particular air vehicle and the rules of traffic in the sky, but I for one would have to be convinced that aircraft can give better throughput than a road can. On the face of things, I'm not sure that's the case.

cmurf 10y ago

That's for visual flight rules. There's no way this works with VFR. For one, the examples are all major cities where there's Class B airspace, requiring positive separation. So it's basically "clear of clouds", however that assumes you're cleared into Class B. There's no possible way this works with the existing ATC system. Flying cars won't use the same airspace as turbine powered airline planes, so a new airspace designation could exist just for cars. And drones. Because drones and flying cars will be competing for the same airspace so all of them will need to use the same system. Added: Flying cars (and to some degree drones) do compete with the same airspace as existing general aviation flights. And that's a big problem. The legacy aircraft would have to avoid the new airspace, most won't ever get an upgrade to fly autonomously; alternatively, the flying cars will have to be programmed such that they can always yield right of way to legacy aircraft.