Even setting aside the GPS/tablet/etc. question, I think you'd probably be astonished to learn how simple and how old the technology of automatic/instrument lan

Even setting aside the GPS/tablet/etc. question, I think you'd probably be astonished to learn how simple and how old the technology of automatic/instrument landing is. Instrument landing systems date to the 1920s, a time when flying at night, or above cloud tops, was incredibly dangerous. Imagine setting up a couple of directional radio antennas at the end of the runway. One broadcasts short beeps with long pauses (beep-----beep-----beep), the other broadcasts long beeps with short pauses (--beeeep--beeeep--). Set up the antennas so that if you're lined up horizontally with the center of the runway, the signals merge into a continuous tone (beeeeeeeeeeeeeeeeeep). That's more or less how instrument landing systems still work today. Modern ones have more antennas and coordinate you both vertically (on the correct slope to touch down at the start of the runway) and horizontally, but the whole thing is still based on directional radio signals that you pick up from your plane, and a published set of information for each airport (the "approach plate") telling you what frequencies to listen for depending on the runway you want. Airliners can be programmed to "autoland" based on this information, but it requires some setup and also requires the pilots to be ready to take over at a moment's notice (if, for example, controllers at the airport decide to have the plane land on a different runway).