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Comment by rtkwe | Hacker News Reader

TCAS on a wide variety of Airbus chassis can actually automatically fly the collision avoidance directives.

https://skybrary.aero/articles/autopilotflight-director-apfd...

Granted it's muuuuch easier in planes because 1) they're already being routed to avoid each other by humans when the route is setup, 2) they continually announce their position with a high degree of accuracy, 3) generally speaking only two planes will be that close to each other at a time in the air so deconflicting doesn't cause huge ripple effects and 4) the sky is really big but also gives them a 3d dimension to play with where streets are 2 dimensional.

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I was a little bit imprecise. Because the article was talking about a stationary obstacle, literally a wall, I was still talking about stationary objects when I said that airplanes don't avoid obstacles. The autopilot of an airplane will not avoid any kind of stationary obstacle, not even a mountain. It can certainly be done; several militaries use terrain–following guidance in both airplanes and missiles. But there’s nothing about the word “autopilot” that should cause people to think that the car will avoid stationary obstacles. An autopilot follows a route and that’s it.

Some aircraft can avoid other aircraft under some circumstances but those aren’t stationary obstacles and unlike random walls that people build, or mountains, they are all tagged with transponders.

Except terrain following radar also exists for military aircraft. Civilian planes don't have it because it's not something they want or need to do not be cause the capability doesn't exist.

If the plane is anywhere near terrain on autopilot things have gone horribly wrong and a person should be flying anyways.

https://en.m.wikipedia.org/wiki/Terrain-following_radar

Yea, I did say that. There’s no reason for the average person to expect their car’s autopilot to do that. Autopilots follow routes.

> The autopilot of an airplane will not avoid any kind of stationary obstacle, not even a mountain

Well a core part of the flight is colliding with the ground at the end.

But also the hazard of a stationary object doesn’t exist - crew receive an IFR clearance and fly that route; that route won’t have stationary obstacles.

Aviation’s autopilots aren’t “eyes-off” in VFR so that’s a meaningless comparison.

Sure, there’s a good argument that we should limit self–driving cars to predictable environments. For example, we could dig a bunch of tunnels under our cities and have self–driving cars in them. It’s a controlled environment. If the tunnels connect to buildings underground, then the cars would not need to be used on surface roads.

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