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Comment by userbinator | Hacker News Reader

Planes have been flying for decades before GPS even existed, yet the article seems to make it sound like they wouldn't be able to without GPS. Unfortunately no mention of https://en.wikipedia.org/wiki/Inertial_navigation_system at all.

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After the invention of GPS, aviation increased its capabilities due to the advantages GPS provides. Many modern flights depend on those capabilities to be economically viable, and are thus dependent on GPS.

Simply because it’s possible to fly without GPS doesn’t mean it’s commercially viable. Remember, before GPS, direct transatlantic flight weren’t generally possible because there’s no radar or radio coverage out there to help with flight navigation. Also for a long time, plane navigated by flying low and literally following giant arrows on the ground[1]. I doubt anyone is particularly keen to return to that kind of navigation.

[1] https://www.dreamsmithphotos.com/arrow/

We'd definitely need new hardware and/or infrastructure to work without GPS.

> before GPS, direct transatlantic flight weren’t generally possible

I'm not sure what you mean by this. Commercial transatlantic flight picked up after WW2 in the 50s. By the 1970s it was fairly common. A lot of that came from rocketry research and INS.

Not to mention removal of the alternatives in favor of GPS, e.g. shutting down VOR beacons (see e.g. https://www.flightaware.com/squawks/view/1/24_hours/popular/...)

It is interesting to consider how many old mysteries in flying came down to "pilot didn't know where they actually were." This isn't much different from hikers getting stranded, even when they are within a mile of a marked trail.

Nonsense. There were decades of commercial transatlantic flights before the widespread adoption of GPS. No one painted giant arrows on the ocean. Airliners navigated using a mix of dead reckoning, ground signals, and sometimes even celestial observations.

https://www.smithsonianmag.com/air-space-magazine/707-flight...

GPS (and other GNSS) make civil aviation slightly safer and more efficient but it's hardly necessary for routine flight operations.

INS accumulates error though. It comes in handy in the absence of any other navigation system, but generally an INS is supplemented by some sort of radio navigation aid such as VOR, LORAN, or GPS to correct it.

Except guess what! Many of the VOR stations in the USA have been shut down, due to the high availability of GPS!

Note those INS systems depend on some sort of navigational system to verify against due to drift and such, and those systems are GPS or VOR.. and VORs are being shut down or decommissioned as they fail (except for the ones declared required for national security).

In the case of planes celestial navigation is a realistic alternative as they fly most of the time above the cloud cover...

Well, it's just bad journalism, cause what they are referring to is a quantum inertial navigation system, not a clock – it's just thousands of time more precise. The plan happen to also have an atomic clock (which is used to properly integrate inertia through time), without having to rely on external GPS (which is a clock).

You just have to get closer to the source and find better information: https://www.gpsworld.com/uk-government-tests-quantum-inertia...

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