back to article GPS interference now a major flight safety concern for airline industry

Europe's aviation safety body is working with the airline industry to counter a danger posed by interference with GPS signals - now seen as a growing threat to the safety of air travel. The European Union Aviation Safety Agency (EASA) and the International Air Transport Association (IATA) held a recent workshop on incidents …

  1. KittenHuffer Silver badge
    Coat

    Any mention of GPS spoofing .....

    ..... is Fake news!

    Mine's the one with the OS maps in the pocket!

    1. IGotOut Silver badge

      Re: Any mention of GPS spoofing .....

      I see multiple people can't grasp the concept of a joke.

      1. gandalfcn Silver badge

        Re: Any mention of GPS spoofing .....

        No, it sh1te.

      2. KittenHuffer Silver badge

        Re: Any mention of GPS spoofing .....

        I think there might be a number of Commentards that auto-down-vote any mention of 'Fake News'.

        I did consider "Any mention of GPS spoofing is just news of Fake" but felt it didn't have the same punch, and was pretty much like explaining the joke.

        If it 'Whooshed!' a few people and they down voted me then I just have to accept that not everyone has my sense of humour ..... Thank <diety>!

        1. Sceptic Tank Silver badge
          FAIL

          Re: Any mention of GPS spoofing .....

          Downvoted for mentioning "Fake News"

    2. Doctor Syntax Silver badge

      Re: Any mention of GPS spoofing .....

      But how do you know they're genuine OS maps?

      1. KittenHuffer Silver badge

        Re: Any mention of GPS spoofing .....

        But Shirley, PB would never return results for Fake OS maps?!? I'm shocked that such a thing could happen!

  2. alain williams Silver badge

    Is it naive to suggest ...

    that aircraft GPS receivers should only look upwards as that is where the GPS satellites are ? Yes: I know that there are not a vast number of the satellites and so that some might, at times, appear close to the horizon ...

    Different for GPS receivers in cars/ships/... which are not high up.

    1. Jim Mitchell

      Re: Is it naive to suggest ...

      But then you lose GPS when doing a 5G inverted dive with a MIG.

    2. Corin

      Re: Is it naive to suggest ...

      I'm here to literally ask the same thing. On the assumption that the jamming is originating from the ground, and the desired signal is originating from the sky, is it possible to solve for that?

      I suppose the challenges are likely to be to do with any additional weight, certifying the newly redesigned receiver as sufficiently accurate and reliable, and the risk of your adversary emitting a jamming signal from another aircraft.

      1. Paul Crawford Silver badge

        Re: Is it naive to suggest ...

        Part of the issue is the cost of a system that can reliably detect the incoming angle of a signal to help mitigate ground-based spoofing, but jamming just needs a strong signal and it can be hard to stop something ground based from tens of km away that is a million times stronger then that wanted satellite signal that is ~10,000 km away.

        1. cyberdemon Silver badge

          Re: Is it naive to suggest ...

          Presumably a ground-based signal could also reflect off the ionosphere. Don't know if that applies to GPS signals (~1GHz?) though?

          1. IvyKing

            Re: Is it naive to suggest ...

            The highest frequencies that can be refracted (not reflected) by the ionosphere is a bit north of 200MHz when there is heavy ionization in the E-layer. This known as sporadic E-skip and appears to be caused very large thunderstorms sending charge up to the ionosphere (sprites, jets, etc). The worst that happens at 1+ GHz is that the ionosphere causes the velocity of propagation to slow down a bit and shifting apparent location.

            Using a directional antenna to verify that the signal supposedly coming from a particular satellite really is coming from that satellite should be able to detect spoofing and may be able to null out the interfering signal.

      2. jmch Silver badge

        Re: Is it naive to suggest ...

        "...the risk of your adversary emitting a jamming signal from another aircraft."

        Especially if dealing with nation-state actors there's a fairly high possibility of this. I guess one way would be to update the GPS satellites to send some kind of encrypted hash that receivers could authenticate with a public key but attackers couldn't replicate. Not sure if that would be at all possible simply by a software update or if it would require a whole new generation of satellites. (and there's always the possibility of the original encryption keys leaking or being exfiltrated by malicious actors)

        1. Lurko

          Re: Is it naive to suggest ...

          As it's mostly nation-states, I'd have thought that the simple trick would (if not already the case) be to use a dedicated satellite to interfere with the legit satellite transmissions. Then the "directional defence" of upward antennae falls apart.

          1. jdiebdhidbsusbvwbsidnsoskebid Silver badge

            Re: Is it naive to suggest ...

            Putting something into space is never simple. Far simpler to leave it on the ground and crack the gain up. If it's taken out by enemy forces, just pop another one in its place.

            If you really must have your jammer off the ground, just pop it on a drone.

            1. Doctor Syntax Silver badge

              Re: Is it naive to suggest ...

              Navigating the dronw could get tricky.

            2. I ain't Spartacus Gold badge

              Re: Is it naive to suggest ...

              Drones aren't great for electronic warfare yet. Listening to signals isn't all that power intensive. But jamming requires power, both to over-power the source and to travel long distances. And drones tend to have small engines.

              This is the problem the Royal Navy are looking at. There are persistent drones we could use for radar surveillance, but none with the electrical power required to operate a massive air search radar with a range of a couple of hundred miles. Hence we run our carrier-based radars off a big, fat 3-engined helicopter.

      3. jdiebdhidbsusbvwbsidnsoskebid Silver badge

        Re: Is it naive to suggest ...

        Not naive at all, such antennas do exist. Some provide attenuation to low elevation signals that are more likely to be ground based, others provide a bearing to ground based signals allowing you to actively form a null in the antenna pattern in that direction. Not foolproof though, just providing some resilience against jammers rather than complete resistance.

    3. Lusty

      Re: Is it naive to suggest ...

      Occams razor would suggest it might be easier to just use celestial navigation which is pretty simple alongside modern compute devices with built in tables.

      ICBMs have been doing it this way for decades

      1. gandalfcn Silver badge

        Re: Is it naive to suggest ...

        Indeed, with a sextant and a watch.

    4. veti Silver badge

      Re: Is it naive to suggest ...

      Not just "upwards". There are only 32 currently operational GPS satellites. It shouldn't be impossible to model their orbits and anticipate where in the sky to look for them, within a few degrees.

      1. Anonymous Coward
        Anonymous Coward

        Re: Is it naive to suggest ...

        But you wouldn't know where to look unless you knew your position....

        1. DS999 Silver badge

          Re: Is it naive to suggest ...

          You know your position is pretty close to the position it was a few seconds ago, so unless you are starting from scratch with zero idea of where you are "looking where the GPS satellites should be" a quite reasonable thing.

          The problem with "only looking up" or looking where the GPS satellites are is that's only a solution for new aircraft. Existing ones have GPS antennas where they have them, and retrofitting them with a fancier one that's capable of electronically aiming (or remains omnidirectional but is on top of the aircraft where the fuselage shields it from ground based interference) would not be cheap.

  3. elsergiovolador Silver badge

    Options

    The pilots can always:

    1) Fly above the clouds and look at the visible stars to approximate where they are

    2) Fly below the clouds, open the planes window and shout "Excuse me what country is this?" and "Where is the nearest airport?". To be fair these questions are available for nearly all language dialogue pocket books. They may turn off the engine so they can hear the answer if someone shouts back.

    If above doesn't help, just land and see if you can find a pub or convenience store and ask for directions then continue the flight.

    It's not rocket science.

    Sometimes I think GPS was invented for people with social anxiety, so they don't have to interact with other people when they get lost.

    Also pilots, just like cabbies, should have an exam from the flight routes. If I tell them I want to fly to Acapulco from London, they should easily have the exact route pop in their heads.

    1. Anonymous Coward
      Anonymous Coward

      Re: Options

      point 2 is wrong: As the majority of pilots are men, the chances of them asking for directions is slim

      1. elsergiovolador Silver badge

        Re: Options

        You're right, most likely a stewardess who has had enough of flying in circles would have opened the side door and asked...

        1. Anonymous Coward
          Anonymous Coward

          Open the door to ask.....

          Didn't that happen with a Boeing just last week?

      2. Edward Ashford

        Re: Options

        What they actually do is fly low enough to read the road signs.

    2. Munehaus

      Re: Options

      That could work, at least in Seattle:

      "A helicopter with a pilot and a single passenger was flying around above Seattle when a malfunction disabled all of the aircraft's navigation and communications equipment.

      Due to the darkness and haze, the pilot could not determine the helicopter's position and course to get back to the airport.

      The pilot saw a tall building with lights on and flew toward it, the pilot had the passenger draw a handwritten sign reading, "WHERE AM I?", and hold it up for the building's occupants to see.

      People in the building quickly responded to the aircraft, drew a large sign, and held it in a building window.

      Their sign said, "YOU ARE IN A HELICOPTER."

      The pilot smiled, waved, looked at his map, determined the course to steer to SEATAC airport, and landed safely.

      After they were on the ground, the passenger asked the pilot how the "YOU ARE IN A HELICOPTER" sign helped determine their position.

      The pilot responded, "I knew that had to be the Microsoft support building, they gave me a technically correct but entirely useless answer."

      1. xyz Silver badge

        Re: Options

        Ah the old jokes are the best. I was scanning the comments just hoping to find it.

  4. Fazal Majid

    Iran

    The Iranians used GPS spoofing to capture a US RQ-170 Sentinerl drone in 2011, so they would be a natural suspect for the attacks over Iraq-Iran.

  5. steviebuk Silver badge

    All the more reason

    to not have pilotless planes.

    1. John Brown (no body) Silver badge

      Re: All the more reason

      S'ok, they'll just install ChatGPT on board.

  6. claimed Silver badge

    Alt

    Surely the plane systems can track throttle, start point, maneuvers and measured wind speed etc to approximate a position, and alert when it diverges too much from GPS position, or be used as a backup when GPS is unavailable?

    I know there are a lot of factors, but aside from not being able to measure wind speed (which you should be able to get an update on from a weather beacon at home over another comma channel), what else is the blocker?

    Take the black box data from all the routes that have been flown in the last 10 years (or ongoing from now), and the GPS data, and feed it into an AI model, and see how close we get?

    1. Catkin Silver badge

      Re: Alt

      That's dead reckoning but most planes have very accurate gyros and accelerometers that allow for inertial navigation. It will drift over time but there really should be a system to detect if the GPS suddenly drastically disagrees from inertial.

      1. Lurko

        Re: Alt

        System would then handback control to the crew, raising the question whether modern crews would all cope? AF442 handed control back to the pilots when systems encountered an error condition, and that didn't go so well. Much depends on the training, but also whether trained skills are tested operationally.

        1. Lurko

          Re: Alt

          Correction, AF447.

          1. MiguelC Silver badge

            Re: Alt

            Totally different situation, init?

            1. Lurko

              Re: Alt

              Is it that different? The AF447 crash came about because the crew were unable to fly the aircraft when control was handed back because the systems detected an error. In the case of navigation, so long as pilots ****routinely*** use other systems then we might avoid that. But the evidence from other fields is that humans become overly dependent upon technology that works very well, and then struggle when that technology stops working. There's more than a few other aviation examples or aircraft that crashed because technology failed even though the aircraft was actually flyable.

          2. Catkin Silver badge

            Re: Alt

            I think that differs from a navigation error. It's not so much 'handing back control' as it is highlighting that the navigation is out of whack. There would be plenty of time to follow a procedure to fix location (e.g. entering the control area of a ground-based radar) as opposed to suddenly having to deal with readings that make staying in the air challenging.

            Think back to Korean Air Lines 007, which prompted Reagan to make GPS available to public aviation. Putting aside the shoot-first attitude of the Soviets, there would have been plenty of opportunity to avoid Soviet airspace if they'd been alerted to their loss of heading.

      2. Anonymous Cowpilot

        Re: Alt

        We already get alerts when GPS conflicts with inertial nav systems. It happens a few times on a normal flight so is pretty common. Navigation without GPS is common and pretty easy. However, drones often rely exclusively on GPS and some of this is aimed at the growing use of drones in aviation. Also, recently more and more airports are using approach procedures such as RNAV that need a strong GPS fix. If you don't have a good fix you still know where you are but the airport may not let you join the approach (because it means they have to switch from RNAV to ILS or another approach type that requires much bigger separation between aircraft, which makes the airport less money).

        1. claimed Silver badge

          Re: Alt

          Ah, thanks for the answer, that makes sense! It also makes sense that it comes back to money and not technical feasibility!

      3. swm

        Re: Alt

        I once asked the pilot of a 747 how accurate their inertial guidance system was (They had three systems). He said that on a trip over the Atlantic ocean it would be accurate to within a mile. Enough to find the airport but not enough to land. That was decades ago.

  7. Gene Cash Silver badge

    WTF did people do before GPS?

    I'm actually old enough to remember life before GPS (and the internet too, but that's another topic)

    They seemed to get along fine then. They no longer have backup navigation methods? Was getting rid of the inertial navigation system part of the cost-cutting?

    1. WonkoTheSane Silver badge
      Headmaster

      Re: WTF did people do before GPS?

      Before GPS, pilots were taught to follow the line of roads, rivers & railway lines.

      1. MiguelC Silver badge
        WTF?

        Re: WTF did people do before GPS?

        While crossing oceans?

        1. Catkin Silver badge

          Re: WTF did people do before GPS?

          Those were done based on inertial headings with VHF (VOR) assistance. It didn't always work out if it wasn't programmed correctly (also a problem with GPS but that's more closed loop and can be interrogated if an error is detected), for example, KAL007.

      2. Anonymous Cowpilot

        Re: WTF did people do before GPS?

        Helicopter pilots are told to do that. Plane pilots are told not to do that. We plot a course on a map and adjust for wind speed and compass error. Then we fly the course and check way points to see where we are.

        This is still the main approach to navigation for light aircraft and the only method allowed in an exam.

        1. I don't know, stop asking me.

          Re: WTF did people do before GPS?

          > This is still the main approach to navigation for light aircraft and the only method allowed in an exam.

          Yean, right up until you start your instrument training.

          the vast majority of commercial flight is under IFR.

    2. Munehaus

      Re: WTF did people do before GPS?

      Google Korean Airlines flight 007. It's one reason why GPS selective availability was removed.

  8. elsergiovolador Silver badge

    Net Zero

    To be fair, in fight for Net Zero airlines should be legally forced to ensure that the customer absolutely has to take the flight. They could for instance do the following:

    - Ask why they want to fly there and what happens if they don't go.

    - Ask if they could use Teams instead of going face to face and if meeting is sensitive, they could use Signal.

    - If it's about meeting a partner, give them premium account at triple x site for a month and ask to come back in a few days whether they still want to meet the partner

    - If they still want to meet their partner, ask them to spend few days on Tinder to find a partner with lower carbon footprint

    - If they want to see some landmarks or stay at the beach, redirect them to Argos to buy a fan, heater, lamp and beach coconut room scent and grab bottle of Rum at Sainsbury's. Throw in discount at local tanning shop. For landmarks send a link to some YouTuber reviewing the landmark.

    - If they want to taste food, link up with Deliveroo

    Alternative create a package that contains hypnosis session, used tickets, souvenirs, AI made photos and artificially induced STD.

    If after all this person still wants to fly, try to book them with 737 MAX.

    1. Anonymous Coward
      Anonymous Coward

      Re: Net Zero

      Those downvotes are from people who have to use Teams instead of Zoom.

    2. R Soul Silver badge

      Ask if they could use Teams instead of going face to face

      FFS!

      There must be many people like me who'd pick travel in a dodgy Boeing before they'd use Teams.

      1. JimboSmith Silver badge

        Re: Ask if they could use Teams instead of going face to face

        FFS!

        There must be many people like me who'd pick travel in a dodgy Boeing before they'd use Teams.

        After the problem I had today with the memory hog that is Teams buggering up my afternoon I’m not adverse to a horse and cart either.

    3. John Brown (no body) Silver badge

      Re: Net Zero

      "- If they want to see some landmarks or stay at the beach, redirect them to Argos to buy a fan, heater, lamp and beach coconut room scent and grab bottle of Rum at Sainsbury's. Throw in discount at local tanning shop. For landmarks send a link to some YouTuber reviewing the landmark."

      I was thinking along similar lines, but hadn't got to the Youtuber idea. My idea was for personalised local tour guides with VR cameras live streaming to your shiney new VR headset :-)

      Advancing towards net zero and giving the holiday spot locals alternative employment to serving drinks or waiting tables.

  9. Andre Carneiro

    Galileo to the rescue?

    I was under the impression that the Galileo system had some sort of encrypted broadcast as well as the “peasant signal” exactly to prevent spoofing?

    Not sure if that one was for military-only or for civilian use (for a fee), but I think the technology already exists and is deployed.

    1. jdiebdhidbsusbvwbsidnsoskebid Silver badge

      Re: Galileo to the rescue?

      Yes Galileo is more resistant then NAVSTAR because the satellite signals are higher power and have better encoding for processing gain. But that just raises the bar, it doesn't guarantee resilience.

    2. Anonymous Coward
      Anonymous Coward

      Re: Galileo to the rescue?

      All the encryption in the world isn't going to help when your GNSS receiver(s) can't hear the signal.

      1. Anonymous Coward
        Anonymous Coward

        Re: Galileo to the rescue?

        That's half the battle - not being tricked into following a false signal.

      2. KarMann Silver badge
        Stop

        Re: Galileo to the rescue?

        Andre was explicitly addressing spoofing, not jamming. You're only addressing jamming.

    3. hallmark

      Re: Galileo to the rescue?

      I fly with a Foreflight Sentry portable backup receiver ($599). One of the features is that it will revert to Galileo if the US GPS system is compromised. Other than a Foreflight subscription, there are no other fees.

  10. Marty McFly Silver badge
    Meh

    Redundant

    Modern aircraft are full of redundant systems, and logic flow charts determine operational functionality & availability of systems. It should be trivial to detect whether a current GPS reading is trustworthy or not. For example...

    - Compass points north, thus it shows the general direction of the aircraft travel. Are GPS coordinates changing in a similar fashion?

    - Engines are at cruise speed, which means the aircraft should be moving along 400-600mph depending on head/tail winds. GPS should not show a speed less than 300 or more than 800.

    - Etc.

    If the GPS data is deemed to inaccurate, that would just mean the pilots need to do more work navigating the aircraft manually. Some automated systems would become unavailable. But hardly a 'major flight safety concern', at least as long as there are humans in both front seats.

    1. Anonymous Coward
      Anonymous Coward

      Re: Redundant

      It's like backup, unless it is tested regularly - both the system integrity and human knowledge of how to use it - it is more likely than not to fail when needed.

    2. gandalfcn Silver badge

      Re: Redundant

      "- Compass points north" Er, no, the magnets align with the local magnetic field.

    3. Fursty Ferret

      Re: Redundant

      What's happening is that the spoofed position is about 60 miles west of the true position. When the incorrect position is first calculated, it's rejected by the flight management computers (FMCs) as it differs significantly from that derived from inertial positioning. Plane continues trundling on the correct course. So far so good.

      Over time the FMCs start to take a closer look at the GNSS signal, and consider that it's been like that for a while. So they begin to give it a little more credence. What if it's right? So they start to bias their calculated position with an element of the (incorrect) GNSS location. You're still within the required navigation performance limits, but with some uncertainty. Various non-critical navigation systems have failed at this point, including position reporting and look-ahead ground proximity warnings.

      Finally, your FMC locks onto a basic navigation beacon on the ground. Aha! We only know the line-of-sight distance from the beacon, but that's enough to confirm position to within a mile. Except that what's happened is that the sneaky Iranians have built a radio beacon that broadcasts on the same frequency as the one that your FMC is looking for. The FMC discovers that the calculated radio position matches the spoofed GNSS location and thinks "shit, I'm off course".

      Remember how the spoofed position was 60 miles west of true? This means that to re-acquire the correct track you need to fly east by 60 miles, which is just enough to put you nicely inside Iranian airspace without permission. I think it's very unlikely that you'd be shot down, but a Western airliner forced to land at an Iranian military airfield is an enormous political bargaining chip. Would the Iraqis provide a warning that you were off track? Possibly. But given the Americans named the primary navigation waypoint in the country "Rag-head" and have vetoed attempts to change it for years, I doubt they'll be hugely interested in helping.

  11. short

    Well, yes

    This is one of the main reasons people have been banging on about eLORAN and the like for years, and wincing when usable LORAN-x transmitter towers got taken down.

    The physics of earth-bound transmission and high powers help substantially.

    1. gandalfcn Silver badge

      Re: Well, yes

      Decca Navigator?

  12. Doctor Syntax Silver badge

    Nobody suggested a few missiles locked onto the spoof/jammers?

  13. gandalfcn Silver badge

    Retaining traditional navigation aids. With a sextant,did you say?

  14. Evil Scot Bronze badge
    Gimp

    Just one problem.

    To accurately ascertain the position of the jammer one needs an accurate time record at the two or three ground nodes to calculate the time of flight.

    Trouble is the clock source used by these nodes, is being jammed.

    (Icon = Lead Dev's GIT account avatar)

  15. The Dark Side Of The Mind (TDSOTM)

    Old proven ways with modern approaches

    Smarter persons than me already mentioned inertial and celestial systems, as well as known ground references (optical and/or radio based). Adding signal analysis (polarization, power, timed variation and directionality) would be feasible with modern computational means.

    I remember that gravimetric maps were considered "strategic and restricted data" on grounds that they were used to at least help ICBMs (and other flying contraptions) to get a reasonable "fix" on the map/path*.

    With enough motivation, the industries will find solutions. Politics might interfere a while, for better or for the worse, but with proper incentives, education and training, it's achievable.

    I'm an old fart that remembers the time before Internet was available to mere mortals and GPS electronics was carried in a pick-up truck, so I might have an optimistic bias here.

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