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>In just a couple of years the DARPA challenge yielded cars that can drive themselves in complex urban environments. I imagine with sufficient smart people wor

>In just a couple of years the DARPA challenge yielded cars that can drive themselves in complex urban environments. I imagine with sufficient smart people working on it, flying airplanes in relatively uncluttered sky would yield results faster. As I mentioned, many of the tasks of flying airplanes have been successfully automated. However, there are significant complexities that pilots must deal with that don't apply to cars, and most of those still require human intervention, especially in-flight emergencies. If your car engine quits, you pull over to the shoulder, turn on your hazard lights, and call AAA. If your aircraft engine quits, the response is much more complex. If the power steering on your car quits, you do pretty much the same thing as described above. If your flight controls malfunction in an airplane, the response is much more complex. If your car catches on fire, you do the same as above, plus get out. If your airplane catches on fire, you've got a much bigger problem. I could go on, but I think that gets the idea across. Also, the sky is not "relatively uncluttered." There are a lot of airplanes flying at any given moment, and most of them are concentrated onto airways. It gets even worse in the terminal area: lots and lots of planes coming and going to and from many different directions, all in a very small piece of sky. >As for see-and-avoid, perhaps it works for obstacles on the ground, but other aircraft are moving so fast, is it really feasile to eyeball them before they are on you? Perhaps in pursuit, but at any significant angle they flash past at hundreds of miles an hour. Only radar etc has a chance of identifying/avoiding at those speeds. I am alive today because, on countless occasions, I and my fellow aviators have looked outside, seen another aircraft, and maneuvered to avoid a potential collision. I think that you really don't have an accurate mental image of how this works, so I'll try to explain a little bit: Consider two airliners cruising at 424 kts each, one heading due West, the other due North. The rate of closure is 600 kts. Depending on the atmospheric conditions, they will be visible to each other at about 10 nautical miles, which gives them an entire minute to spot each other and maneuver to avoid a collision. Even if it's two sueprsonic fighters flying right at each other at 600 kts each, they still have thirty seconds to spot each other. A much more realistic scenario would involve two aircraft in the terminal area, where they would be moving much more slowly, giving them much more time to see each other and respond. I think the most dangerous situations are where two aircraft are on headings that are different by less than forty-five degrees: they are basically next to each other, closing from each other's sides where they are less likely to be spotted. The rate of closure is probably very low, but that's more than made up for by the awkward situation in regards to field of view from many cockpits.

yread 15y ago
> If your airplane catches on fire I think that unmanned plane has actually a much better chance of surviving fire, it could have an inert atmosphere, or it could be unpressurized so fires would be much less frequent. Also fires happen mostly on freight planes (lately UPS and Asiana) and freight planes would be probably easier to certify for unmanned flying than passenger planes. > I am alive today because, on countless occasions, I and my fellow aviators have looked outside, seen another aircraft, and maneuvered to avoid a potential collision. Isn't this what Traffic collision avoidance system (TCAS) is for? The pilots already have to do as they are told by TCAS (after the collision over Switzerland). Surely managing traffic of obedient agents with known limits of performance isn't that hard - if all the planes were unmanned there wouldn't be problems However, the points that you mentioned about other emergencies and passenger traffic still stand.
- lucasjung 15y ago
  >it could have an inert atmosphere This would be very costly to implement, and probably very heavy. That being said, inert gases are used in places where arcing is likely (e.g. radar waveguides). >or it could be unpressurized so fires would be much less frequent I really don't think this would have a significant impact on the frequency of fires. Plus, a lot of avionics need particular environmental conditions, in some cases including pressurization. >Also fires happen mostly on freight planes High-power electronics, such as military radars, also pose an increased risk of fire. >freight planes would be probably easier to certify for unmanned flying than passenger planes. If you only cared about the contents of the plane, this would be true. But what happens when a flaming ball of wreckage that used to be an unmanned freight plane plows into a suburban neighborhood, a school, or a downtown skyscraper? >Isn't this what Traffic collision avoidance system (TCAS) is for? The pilots already have to do as they are told by TCAS (after the collision over Switzerland). TCAS isn't all it's cracked up to be. First of all, it only works if the other plane has a transponder (there are still plenty of light civil aircraft out there with no transponders). Second, there are different versions out there with different levels of accuracy. The older kind are not very accurate at all, and basically serve only to give the pilot a general idea of where to look in order to spot the traffic and avoid the collision the old-fashioned way. The more accurate kind only works if both aircraft involved have the necessary equipment. As for the collision over Switzerland, the reason for that rule is that the collision happened in part because TCAS and ATC gave conflicting instructions: one told plane A to go up and plane B to go down, the other told plane A to go down and plane B to go up. One crew did what TCAS said, the other did what ATC said, and they both ended up descending. So the reason for this rule isn't that TCAS is a magical panacea for midairs, but rather a way to consistently resolve any future such conflicts between TCAS and ATC. >Surely managing traffic of obedient agents with known limits of performance isn't that hard - if all the planes were unmanned there wouldn't be problems If all the planes were unmanned, then managing traffic would be much easier, but that still leaves other issues, like where a plane ends up when it malfunctions and crashes. It would also require a wholesale changeover that simply isn't plausible.

yread 15y ago

> If your airplane catches on fire I think that unmanned plane has actually a much better chance of surviving fire, it could have an inert atmosphere, or it could be unpressurized so fires would be much less frequent. Also fires happen mostly on freight planes (lately UPS and Asiana) and freight planes would be probably easier to certify for unmanned flying than passenger planes. > I am alive today because, on countless occasions, I and my fellow aviators have looked outside, seen another aircraft, and maneuvered to avoid a potential collision. Isn't this what Traffic collision avoidance system (TCAS) is for? The pilots already have to do as they are told by TCAS (after the collision over Switzerland). Surely managing traffic of obedient agents with known limits of performance isn't that hard - if all the planes were unmanned there wouldn't be problems However, the points that you mentioned about other emergencies and passenger traffic still stand.

lucasjung 15y ago
>it could have an inert atmosphere This would be very costly to implement, and probably very heavy. That being said, inert gases are used in places where arcing is likely (e.g. radar waveguides). >or it could be unpressurized so fires would be much less frequent I really don't think this would have a significant impact on the frequency of fires. Plus, a lot of avionics need particular environmental conditions, in some cases including pressurization. >Also fires happen mostly on freight planes High-power electronics, such as military radars, also pose an increased risk of fire. >freight planes would be probably easier to certify for unmanned flying than passenger planes. If you only cared about the contents of the plane, this would be true. But what happens when a flaming ball of wreckage that used to be an unmanned freight plane plows into a suburban neighborhood, a school, or a downtown skyscraper? >Isn't this what Traffic collision avoidance system (TCAS) is for? The pilots already have to do as they are told by TCAS (after the collision over Switzerland). TCAS isn't all it's cracked up to be. First of all, it only works if the other plane has a transponder (there are still plenty of light civil aircraft out there with no transponders). Second, there are different versions out there with different levels of accuracy. The older kind are not very accurate at all, and basically serve only to give the pilot a general idea of where to look in order to spot the traffic and avoid the collision the old-fashioned way. The more accurate kind only works if both aircraft involved have the necessary equipment. As for the collision over Switzerland, the reason for that rule is that the collision happened in part because TCAS and ATC gave conflicting instructions: one told plane A to go up and plane B to go down, the other told plane A to go down and plane B to go up. One crew did what TCAS said, the other did what ATC said, and they both ended up descending. So the reason for this rule isn't that TCAS is a magical panacea for midairs, but rather a way to consistently resolve any future such conflicts between TCAS and ATC. >Surely managing traffic of obedient agents with known limits of performance isn't that hard - if all the planes were unmanned there wouldn't be problems If all the planes were unmanned, then managing traffic would be much easier, but that still leaves other issues, like where a plane ends up when it malfunctions and crashes. It would also require a wholesale changeover that simply isn't plausible.