> Uhm, "traffic at terminal ends" suggests the real problem is that the correct path is not known in the beginning, or that autopilot might not be able to avoid collision on its own... which is quite a bit different from the plane being unable to locate itself accurately and follow the correct path even if it were known a priori. Are we even discussing the original issue at this point?
Your thesis of your statements is that it is ridiculous that there is no moving map for pilots to see on the airplane. You've been told directly by some commenters that there is (tuxer), and others, including me, have said that GPS is not the way to land a plane.
>I have no idea what that means. I'm not sure what gave you the impression that I know what that means either.
I mean this in a positive way, but you should look it up on wikipedia. There are many great articles about the systems in place for instrument approaches and landings, and you may learn something interesting for a quick 15 minute investment.
> My problem is whether GPS is accurate/reliable enough to lead the plane to the place where the next system can take over, which to me implies GPS is already certified to be accurate and reliable enough to get the plane near the correct runway. Read it again.
You call us out for dismissing your idea (And, as a computer scientist, what seems ridiculous to me is the idea that "Oh, but this system you just described won't work..."), which to mean seems to be some sort of GPS en-route to to landing automated system. This idea has been informed by your inaccurate reading of a CNBC article (So it seems clear in normal situations autopilot has plenty of positioning available to it, enough to find the runway and locate the plane on a display of some sort. That goes pretty clearly against what you said. Am I missing something?). The en-route exists but can often change from the time the plane leaves the ground to when it gets within 50-100 miles of the airport, at which time it might be disengaged and switched to VOR based navigation. The landing by GPS does not exist because it is a lot less accurate than the existing systems.
This branch of the thread is about auto landing, and you were talking about how it's absurd GPS is approved for automated flying. Given that GPS is used for en-route navigation and not landing, the assumption was that you were proposing GPS landing systems. That is what my comment is about. And yes, having autopilot disengage at 50 feet above the ground when the pilot is not expecting it can be fatal. I would say that for the landing stage it has to be all or nothing. And you've been suggesting cutting out the human component by proposing an system that goes from take off to landing without manual intervention! Even if there is still a pilot in the cockpit, it still takes a few seconds for the brain to spin up to take over a task from the computer.
It's awesome that as someone outside the aviation industry, you're curious about how it works. Your incredulous tone and sense of superiority (As a computer scientist, as if we should automatically and uncritically defer to your opinion, and I say that as a programmer) is a bit off-putting. If you had just done the basic amount of research you could have come back with a list of questions such as:
- Is GPS used to navigate planes from take off to landing? What else is used?
- Why was the pilot in this incident not using automation to land the plane? How often does this happen?
- What is the procedure for switching between different navigation technologies at different points of the flight? I know that take offs and landings can be manual, but when does autopilot kick in?
- Why is GPS not used to land planes?
- What equipment to pilots use in the cockpit? If they are not the latest and greatest, why?
We could then have had a proper discussion surrounding the need for backwards compatibility, the rolling out of ADS technology, how its absurd we still use voice over radio as a primary way of relaying commands, etc. Pilots and others in the aviation industry generally do believe that a lot of the technology guiding our largest planes is antiquated, but you trivialize it without understanding the full context.