Surely with Radar and transponders you would know relatively where every other plane was in the sky? Also you would have much greater collision warning than 0.1-5 seconds typical of driving.
But surely sir, the sheer volume of space above is more than compensating the increased spacing? Even spacing 500feet apart you can have three levels of traffic up to 2000 feet assuming the floor was 1000 feet in the air for most traffic.
With Radar and/or a ground based transponder position system you would know the precise location of all other traffic in the sky. Surely if a 747 can be autopiloted on a few very ancient computers a modern personal airplane could fly itself on modern technology? You would only need to train people to use their judgement in landing at the right spot especially if the computer can land whereever its told to!
Condensing a bit as too many quote boxes can be disorientating.
Radar isn't particularly precise when you get down to say feet and inches, at least those currently used for air traffic control. And the more precise systems you start using and the more complex control systems, the higher the cost is going to be.
Take a look at the cost of avionics for a modern jet. You'll need something far more complex than that featured in even the F-22 or F-35 if you want to deal with auto-pilot and avoiding collisions in 3 dimensions with vehicles just a few meters apart. Costs are going to rapidly escalate for a system capable of dealing with those situations quickly enough to avoid and accident.
And you will have to spend those costs, as an accident on the road isn't going to have nearly the same consequences as an accident in the air. Especially if you are near any population centers. Additionally the higher you are, the more force you will carry into any impact when you hit the ground, again, increasing the potential for something really bad to happen.
And if you are going to need say a 500 ft bubble around each car, you're not going to be able to have the traffic density of a roadway where you only need a meter or two between cars side to side, and a variable amount front to back depending on speed. You're always going to need a large buffer all the way around a flying vehicle, as there isn't much to prevent the vehicle from going in any direction at any given time depending on circumstances out of the operators controls.
By comparison. Is it cheaper to build a massive new road network or to make sure everyone can get around in flying transportation? If there was a new city being built tomorrow would it not be cheaper to install the guidance systems etc than it is to build a huge and inefficient roading network?
It seems to me that its as much a city/country planning problem as it is a mechanical problem. If cities are building suburbs 50+ miles away from where people want to work, could it be cheaper if people in those suburbs flew into town than building ultra wide highways more than 8 lanes in each direction?
A massive road network will always be cheaper. There are much less safeguards required. Potential high risk danger area's are much more predictable and thus it'll always be easier for say emergency services to arrive at the scene of an accident and hopefully save as many lives as possible. A flying vehicle crashing into the side of an apartment building 8 or 9 stories up is going to be a lot more disasterous than a car crashing into the side of the same building on the ground floor.
When designing for mass commuter traffic, taking into account potential risks and hazards is something you must do. It's one reason why airports are generally located miles away from any population centers generally. Unfortunately, cities have a way of then growing around the airports.
Regards!
Grin...
If the discharge of hydrogen from a fuel cell car isn't considered a problem, why would it be a problem for a plane? Hydrogen is a gas which disperses rapidly and theres no reason to expect it would approach the concentration required of ignition. In addition, a discharge of hydrogen would also cool any hot spots the stream came in contact with, wouldn't it?
The forces involved in a crash of a flying vehicle are going to be far more than a ground vehicle. If you are say 100 meters up in the air prior to crashing, you're going to be carrying a lot of potential energy. Will that be enough to rupture the hydrogen tank, expell it quickly enough to get a good oxygen-hydrogen mix and then contact an exposed flame or spark and ignite? Possibly. And if it does you've just exploded a fuel-air bomb in the middle of a population center.
Ground vehicles are going to have fairly predictable crash and damage scenario's and the forces involved are generally going to be less. Protecting the hydrogen cell is going to be a lot easier (not to say it's going to be easy).
Thats why man invented autopilot! No need to worry about drunk flying if the pilots a computer who doesn't drink!
Well, assuming we make an autopilot orders of magnitude better than what is currently used, that may help to some extent. But even the best autopilot can only deal with situations it's been programmed to understand and react to. That's not such a big problem when there's usually a kilometer or more between planes. Start cramming flying vehicles closer and closer together and you're going to have to deal with any situation mother nature can throw at you.
And that's not even going into the potential of hacking/system failure/etc.
Not saying any of this is unsolveable. But there's a cost associated with everything. And costs associated with mass consumer flight is going to be huge.
As the example the only reason ultra lights (those dinky one many flyers) don't face very stringent rules and regulations is that there are so few of them that the chances of mid-air collision and collateral damage from the fallout is very very small.
Regards,
SB
