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When I recently asked some air traffic controllers what would happen if GPS became unavailable, it was grumpy sounds all around. I understand a scramble to vec

When I recently asked some air traffic controllers what would happen if GPS became unavailable, it was grumpy sounds all around. I understand a scramble to vector everything to land everything would result in a very busy day for them, because suddenly most planes would be unable to safely navigate, and thus effectively grounded. Cutting the budget for ground based navaids is nuts, in my opinion.

Rygian 2y ago
I was under the impression that GPS was a non-critical asset for aviation, ie. any plane can safely stop using it at any given time and keep flying with VOR and other navigational aids. This article [1] introduces some of the scenarios where pilots rely on GPS only: * GPS-based waypoints to optimize routing based on favorable winds and more direct routes even in the absence of VORs. * RNAV departures and arrivals that rely "solely on GPS rather than radio-based [...] aids" with more precise spacing and hence higher capacity. * GPS used as a substitute of ILS for some approaches e.g. in mountainous areas. [1] https://simpleflying.com/gps-in-aviation-pilots-guide/ https://simpleflying.com/gps-in-aviation-pilots-guide/
- xavxav 2y ago
  I would assume its not 'safety critical' but 'business critical', disabling GPS would mean slowing down departures / arrivals which means the airport losing money. I recall there being a similar issue with Lufthansa and SFO causing planes to get rerouted to oakland.
  - m3047 2y ago
    There's a meme driver with safety vs business critical and software types seem to think they're special (a different meme) but I'm starting to understand it's everywhere, which is why nobody notices the software issue creeping into their physical systems thinking. A "business critical" issue is defined by the appetite for risk. Most businesses aren't planning for total economic collapse: losing their accounts receivable is what that would look like. What they are concerned about is losing business to competitors or liability for not fulfilling contracts. Software seems to solve the latter problem with shrinkwrap agreements "not responsible for failure of software". That solves their liability problem; everybody else they'll sue. On the other hand "safety critical" concerns the loss of life or property: the things insurers are traditionally concerned with. So if the plane can land, engine out or GPS out what's the difference? Businesses absolutely care about safety, that's why they buy insurance! Safety programs reduce the need and cost for such insurance. Businesses aren't lying when they say they care about safety. However people swim in the ocean of systems without necessarily being systems thinkers: plugging a leak is plugging a leak. But a leaky roof is not the same as a leaky hull. All the people in cybersecurity warning of the dire consequences of breaches are proven wrong time and again by the market: look at the stock prices of Equifax, Solarwinds, United Health Care. It's not simply marketing, a lot of these people really Want To Believe (tm). In the end business is never safe, it's taking risks all the time. Mostly it doesn't see a need to share those risks with customers (or competitors).
- hugh-avherald 2y ago
  It's not safety-critical for a plane, in the sense that if a plane's GPS fails it can still get by safely. It's safety-critical for aviation, because if all GPS fails, then the additional workload across the system means that a crash is likely.
wkat4242 2y ago
They do have other ways to navigate. Like land-based beacons (VORs). Unfortunately these are being used less and less and even deprecated in favour of GPS waypoints. Even when they are still around the pilots have less experience with them because they no longer use them every day.
- nonrandomstring 2y ago
  > Unfortunately these are being used less and less and even deprecated Fortune may have something to do with it. Like copper land communications that cost billions to establish over almost 100 years, are extremely resilient and can be repaired by anyone with a ladder and pair of pliers. They're being ripped out across Europe and the US because the private companies they were sold to want to shrug maintenance to squeeze out a little more profit. It's just not your fortune.
  - pixl97 2y ago
    Copper land lines cost a fortune to maintain, and with everyone having moved to cellphones years ago, don't generate income to pay for their upkeep. People pay far more for an internet line that dumps out a gig of traffic, while very few pay for a hard line that is hard to cut and only carries a few kb of traffic.
    - nonrandomstring 2y ago
      > everyone having moved to cellphones years ago That is untrue. The news is full of stories of people who are right now being forced-off hard line connections that they want and will pay for. The choice is being removed, which is not a fair market. But, telling any group of people that "they are the only ones" is gas-lighting. Systematic lies to marginalise people was central to the Purdue Pharma opioid scandal and to the British Post Office scandal - telling people "You're the only one" when a problem is evidently extensive should be a very serious fraud. > don't generate income to pay for their upkeep When many private companies took on telecommunications properties they did so under obligations to maintenance of infrastructure, availability and reliability standards. If it turns out their choices of technology don't meet those standards of affordable resilience then that's their financial miscalculation and their problem now. Or are you saying that markets are incompatible with national security?
distances 2y ago
GPS is now often unavailable in eastern/northern parts of Europe due to Russian jamming. Some smaller airfields already had to update their systems not to rely only on GPS.
- tambre 2y ago
  Finnair at the end of last month suspended service between Helsinki and Tartu due to Russia's GPS jamming [0]. DME is being added next week and they'll resume service next month [1]. [0]: https://news.err.ee/1609328058/finnair-suspends-flights-to-tartu-for-1-month-to-seek-gps-jamming-solution https://news.err.ee/1609328058/finnair-suspends-flights-to-t... [1]: https://news.err.ee/1609343694/finnair-restarts-tartu-flights-after-alternative-to-gps-approach-systems-found https://news.err.ee/1609343694/finnair-restarts-tartu-flight...
  - toomuchtodo 2y ago
    Would it be accurate to say that DME is the equivalent of the deprecated US LORAN nav system? https://en.wikipedia.org/wiki/LORAN https://en.wikipedia.org/wiki/LORAN
    - lsh123 2y ago
      DME (distance measuring equipment) is much simpler than LORAN. However, navigation computers can use multiple VOR / DME signals to compute position similar to LORAN or GPS. The problem is that DME / VOR are typically limited to 50-200nm (and even lower at lower altitudes) which requires extensive network to make it comparable to GPS / LORAN.
      - toomuchtodo 2y ago
        I appreciate the reply. Are there any canonical reference sources you would recommend to learn more about this implementation? Edit: sources provided are helpful, thank you lsh123 and Animats!
        2y ago
fulafel 2y ago
GPS is only one of three currently deployed satellite positioning systems, why aren't planes using the others?
- mikewarot 2y ago
  All of them share the same reciever and generally the same frequency bands. Jamming one, jams them all.
  - fulafel 2y ago
    Wikipedia has this, is it wrong? > An anonymous EU official claimed that the US officials implied that they might consider shooting down Galileo satellites in the event of a major conflict in which Galileo was used in attacks against American forces.[34] The EU's stance is that Galileo is a neutral technology, available to all countries and everyone. At first, EU officials did not want to change their original plans for Galileo, but they have since reached the compromise that Galileo is to use different frequencies. > This allows the blocking or jamming of either GNSS without affecting the other.[35]

Rygian 2y ago

I was under the impression that GPS was a non-critical asset for aviation, ie. any plane can safely stop using it at any given time and keep flying with VOR and other navigational aids. This article [1] introduces some of the scenarios where pilots rely on GPS only: * GPS-based waypoints to optimize routing based on favorable winds and more direct routes even in the absence of VORs. * RNAV departures and arrivals that rely "solely on GPS rather than radio-based [...] aids" with more precise spacing and hence higher capacity. * GPS used as a substitute of ILS for some approaches e.g. in mountainous areas. [1] https://simpleflying.com/gps-in-aviation-pilots-guide/ https://simpleflying.com/gps-in-aviation-pilots-guide/

xavxav 2y ago
I would assume its not 'safety critical' but 'business critical', disabling GPS would mean slowing down departures / arrivals which means the airport losing money. I recall there being a similar issue with Lufthansa and SFO causing planes to get rerouted to oakland.
- m3047 2y ago
  There's a meme driver with safety vs business critical and software types seem to think they're special (a different meme) but I'm starting to understand it's everywhere, which is why nobody notices the software issue creeping into their physical systems thinking. A "business critical" issue is defined by the appetite for risk. Most businesses aren't planning for total economic collapse: losing their accounts receivable is what that would look like. What they are concerned about is losing business to competitors or liability for not fulfilling contracts. Software seems to solve the latter problem with shrinkwrap agreements "not responsible for failure of software". That solves their liability problem; everybody else they'll sue. On the other hand "safety critical" concerns the loss of life or property: the things insurers are traditionally concerned with. So if the plane can land, engine out or GPS out what's the difference? Businesses absolutely care about safety, that's why they buy insurance! Safety programs reduce the need and cost for such insurance. Businesses aren't lying when they say they care about safety. However people swim in the ocean of systems without necessarily being systems thinkers: plugging a leak is plugging a leak. But a leaky roof is not the same as a leaky hull. All the people in cybersecurity warning of the dire consequences of breaches are proven wrong time and again by the market: look at the stock prices of Equifax, Solarwinds, United Health Care. It's not simply marketing, a lot of these people really Want To Believe (tm). In the end business is never safe, it's taking risks all the time. Mostly it doesn't see a need to share those risks with customers (or competitors).
hugh-avherald 2y ago
It's not safety-critical for a plane, in the sense that if a plane's GPS fails it can still get by safely. It's safety-critical for aviation, because if all GPS fails, then the additional workload across the system means that a crash is likely.

wkat4242 2y ago

They do have other ways to navigate. Like land-based beacons (VORs). Unfortunately these are being used less and less and even deprecated in favour of GPS waypoints. Even when they are still around the pilots have less experience with them because they no longer use them every day.

nonrandomstring 2y ago
> Unfortunately these are being used less and less and even deprecated Fortune may have something to do with it. Like copper land communications that cost billions to establish over almost 100 years, are extremely resilient and can be repaired by anyone with a ladder and pair of pliers. They're being ripped out across Europe and the US because the private companies they were sold to want to shrug maintenance to squeeze out a little more profit. It's just not your fortune.
- pixl97 2y ago
  Copper land lines cost a fortune to maintain, and with everyone having moved to cellphones years ago, don't generate income to pay for their upkeep. People pay far more for an internet line that dumps out a gig of traffic, while very few pay for a hard line that is hard to cut and only carries a few kb of traffic.
  - nonrandomstring 2y ago
    > everyone having moved to cellphones years ago That is untrue. The news is full of stories of people who are right now being forced-off hard line connections that they want and will pay for. The choice is being removed, which is not a fair market. But, telling any group of people that "they are the only ones" is gas-lighting. Systematic lies to marginalise people was central to the Purdue Pharma opioid scandal and to the British Post Office scandal - telling people "You're the only one" when a problem is evidently extensive should be a very serious fraud. > don't generate income to pay for their upkeep When many private companies took on telecommunications properties they did so under obligations to maintenance of infrastructure, availability and reliability standards. If it turns out their choices of technology don't meet those standards of affordable resilience then that's their financial miscalculation and their problem now. Or are you saying that markets are incompatible with national security?

distances 2y ago

GPS is now often unavailable in eastern/northern parts of Europe due to Russian jamming. Some smaller airfields already had to update their systems not to rely only on GPS.

tambre 2y ago
Finnair at the end of last month suspended service between Helsinki and Tartu due to Russia's GPS jamming [0]. DME is being added next week and they'll resume service next month [1]. [0]: https://news.err.ee/1609328058/finnair-suspends-flights-to-tartu-for-1-month-to-seek-gps-jamming-solution https://news.err.ee/1609328058/finnair-suspends-flights-to-t... [1]: https://news.err.ee/1609343694/finnair-restarts-tartu-flights-after-alternative-to-gps-approach-systems-found https://news.err.ee/1609343694/finnair-restarts-tartu-flight...
- toomuchtodo 2y ago
  Would it be accurate to say that DME is the equivalent of the deprecated US LORAN nav system? https://en.wikipedia.org/wiki/LORAN https://en.wikipedia.org/wiki/LORAN
  - lsh123 2y ago
    DME (distance measuring equipment) is much simpler than LORAN. However, navigation computers can use multiple VOR / DME signals to compute position similar to LORAN or GPS. The problem is that DME / VOR are typically limited to 50-200nm (and even lower at lower altitudes) which requires extensive network to make it comparable to GPS / LORAN.
    - toomuchtodo 2y ago
      I appreciate the reply. Are there any canonical reference sources you would recommend to learn more about this implementation? Edit: sources provided are helpful, thank you lsh123 and Animats!
      - 2y ago

fulafel 2y ago

GPS is only one of three currently deployed satellite positioning systems, why aren't planes using the others?

mikewarot 2y ago
All of them share the same reciever and generally the same frequency bands. Jamming one, jams them all.
- fulafel 2y ago
  Wikipedia has this, is it wrong? > An anonymous EU official claimed that the US officials implied that they might consider shooting down Galileo satellites in the event of a major conflict in which Galileo was used in attacks against American forces.[34] The EU's stance is that Galileo is a neutral technology, available to all countries and everyone. At first, EU officials did not want to change their original plans for Galileo, but they have since reached the compromise that Galileo is to use different frequencies. > This allows the blocking or jamming of either GNSS without affecting the other.[35]