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Ep 37 – GPS Jamming and Spoofing

Podcast | September 6, 2024

Hello again. I have trying to record this podcast, however every time I set up to record, more information comes out to warn us about GPS spoofing and jamming. Welcome to the podcast.

This is something of great concern when it happens because you may not know that it’s happening at all. When GPS was new, I think we as pilots cross checked our position more often because it was new. Time has passed and the reliability of GPS and the GNSS constellation and all the other global constellations has been so incredibly reliable that we may have become too reliant or even complacent. This may have to change. Spoofing and jamming is happening in more and more places, and I’m not just talking about flying close to war zones or countries with regimes that indulge in cyber warfare. I’m talking about day-to-day operations. How does your aircraft determine its position? Does your aircraft use DME updating? Does it use VOR/DME or DME DME for position determination?  Where does the Ground Proximity Warning System receive its location information from?

 

What is GPS spoofing?

Ok what is GPS spoofing? The aircraft is sent erroneous data which can result in navigation errors, but the aircraft thinks it’s still in the correct position, therefore no alerts are generated. Your display is normal and portrays information that you believe to be true. In fact, you are not in that location.

 

What is GPS Jamming?

GPS Jamming on the other hand refers to the blocking of the signal altogether so GPS would not be functioning or be available. There may be variations on these definitions out there because this is very new so let me know.

You might be saying, ‘Well, that can’t be happening where I fly?’. Reports have come in from Iraq, Iran, Egypt, Israel, Jordan, Turkey, Cyprus, Lebanon, Pakistan, Niger, Poland, Lithuania, Sweden, Finland and China. A recent article by OpsGroup has reported that Shanwick FIR is encountering many jammed aircraft per day mainly originating from the Middle East. Much of the jamming and spoofing is generated by Russia in response to western allied efforts to thwart the war but who says this technology couldn’t happen far from Russia.

GPS Counter-spoofing

There are some tested and functional GPS COUNTER-spoofing devices or APPs that cross check your location with ground-based navaids and if a position error is detected then a warning message is generated. NaviGuard is one example. Check out their website.

 

GPS Jamming / Spoofing Effects

 

I read a very interesting article on the GPS world website that went into great detail about recent spoofing events, some as far back as 2022. In a nutshell the University of Texas Radio navigation Laboratory and Stanford University tracked the signals to Russia.

The investigators found that several transmitters were used across a wide area to generate the jamming and spoofing events. Some locations jammed GPS signals to just deny service whereas other transmitters sent false locations spoofing the aircraft so the displays would display them far from the actual location, possibly in an attempt to make them fly into the wrong airspace with disastrous results. Recently aircraft have almost entered Iranian airspace unknowingly.

Circle spoofing is a term used in naval industry to describe the act of making a ship think it is in different location. The receiver on the ship is captured and moved to an erroneous location, then it appears to move in circles, usually clockwise.

There are also planned or unplanned outages initiated by the US military in the continental US. Always check those NOTAMs at the bottom of the list.

In 2019, a commercial passenger aircraft flying in smoke nearly impacted a mountain in Sun Valley Idaho during a period of GPS jamming or perhaps an outage. Many aircraft had reported GPS outages in the area and the incident aircraft was cleared for the GPS approach. A Salt Lake City controller noticed the aircraft was off course and contacted the tower at Sun Valley who alerted the aircraft. It is believed that without the ATC intervention the aircraft would have flown into a 10,000-foot mountain in next few minutes.

Awareness of spoofing is growing, and the UN’s International Civil Aviation Organization or ICAO has urged its member nations to take action to prevent it.

But let’s talk more about more simple incorrect GPS location. How would you know if your GPS is simply malfunctioning without an alert? The founder of TrainingPort dot net, Scott Macpherson had an experience a few years ago where the GPS took him and his aircraft to a location in the mountains that was not the intended destination. Scott recorded his experience for you. Here it is.

 

Scott Macpherson’s Take:

Hi, Brent.

I’ve had some concern for quite a while about GPS over reliance and especially when we’re not using blended sensors with full coverage for those sensors, so that could be at distance out over remote territories, or oceanic where GPS is the only realistic navigator for a smaller installation.

Even I think the early Challenger 300s use GPS only and didn’t have IRS in them. Or for smaller aircraft like the King Airs and Citations used in many business aircraft operations which are, say down in the mountains and are relying on GPS but are not in sight of VOR coverage line of sight or any kind of DME or DME kind of coverage where the GPS might have another sensor to blend with.

So they’re concerned for me has been from running a small department that ran very busily, you know, 800 hours a year, about 1000 leagues a year in a Citation in the Rockies, using GPWS, EGPWS and GPS for navigation and protection from terrain, we have the same sensor or the same source coming into our sensors that was the sole source, so if it was wrong, if GPS was wrong, so was our stick map and so was our EGPWS. Of course not the core modes of GPWS, but the enhanced version of the display and the anticipation for turns and so on….that would all be wrong if GPS was lying to us. And as much as people might say, well, that could never happen…have had it go wrong twice in my career I’ve been flying it since the very early days of certified approach on route and approach GPWS or GPS rather from 1993 on and uh first I think the first certification we got for approach use of GPWS was a panel mount and a citation and then later in an FMS Universal FMS.

We’re using approach certified GPS and those were in the mid to late 90s and so that clearly it’s been a long time for me, but we relied entirely on the accuracy.
But now I had to go wrong twice, and in both cases that they went wrong, they were the rain was showing as full coverage and saying nothing was wrong, but we were off course.
And I’ll tell you about the second one, because it’s the most useful.
It was in an FMS based sole source GPS environment where we’re descending into the mountains into an airport we went into all the time, It was the middle of November 2003 and I had briefed a new pilot who was starting with us and had been flying kind of steam gauge citations before and I said, you know, despite how pretty this ephus is, keep in mind that it’s relying only on one GPS.
And he said, yeah, no, I understand and I said so If it’s wrong, everything’s wrong and I said it’s unlikely anything will go wrong because you know it’s a full constellation now.
The error that I saw years ago was before the constellation was complete, and it’s very unlikely any of us are going to see a problem.
But let’s not take our eyes off it and make sure we have the ground navaids tuned up that we can see so in those days we had ADF and DME at this little airport.
We were going to and we were flying along with a high overcast about 18,000 feet above the initial altitude we could descend to on the procedure we were cleared for the approach and I looked as the ADF started to open up to the right and as we broke out of the clouds, the ADF was about 35 degrees off and just before we broke out of clouds, I had asked him so, where do you think the airport’s gonna be? And I washed his eyes.
Drift down to the stick map, which was a pretty tough thing not to look at because it was generally so reliable and he said it would be about 12:15 and I said OK and the DME was also skewing from the GPS distance quite significantly. So it was clearly not right.
And but he was, you know, new to the airplane and and and excellent an excellent pilot, but we just really you know we’re in an unusual circumstance. I had already brought up the satellite page and the rain page and had seen that everything was saying it was OK and I left it up. They’ll be broke out, I said: So I don’t see the airport, do you?
And he said no and I said take a look at the ADF and he spun his head over to the right, saw the airport down that valley now at about 40 degrees and I said we’re early and we’re empty and we’d intentionally departed early and and we’re going to pick people up. I said, why don’t we just let this go?
And now that we’re in clear weather, let’s see where it goes.
And we told ATC what we were up to and they said OK, sure.
And it descended us all the way into a bowl in the mountains, and we didn’t go any deeper in than to make, you know, to find out that the FMS shortly after that suddenly started getting glitchy and then snapped to the right and took us in a Direct Line, which would have been right through a a mountain to the destination. We didn’t go as far into the bowl as to trigger and any of the base. The modes of GPWS, but the EGPWS was telling us everything was fine.
The ADF, the GPS rather, was telling us we were on course even though we were about 15 miles roughly to the north northwest of the airport, we were descending into well off course.
And so we debriefed very well and I pointed out that I said I certainly could never have set this up.
And you probably never ever see a thing like this happen again, but you know, great lesson for both of us and it was a really, you know, a good story because it didn’t get scary, but it was, you know, a sober warning. So I offer that to people, when we think about all the concerns we have with GPS errors spoofing and now the jamming that’s going on and other parts of the world with the two wars that are going on in the Ukraine and in the Middle East, Israel particularly in the and Gaza, these are significant things that are happening. We know that Iran has been jamming, so we’re going to see more and more of this and I think people have to have alternate methods and certainly I’ve read articles about people who are now in her, our audience part of the industry, the business aviation crowd, Who are you know, deselecting GPS? If they’re in areas where they know that this is likely to happen, whether it’s up in the Baltic or down in the Middle East area, obviously nobody’s going near the Ukraine. But these are places where people are having to deselect GPS and make sure that they’ve got good ground based navaids, updating to their IRS and rely on those navaids to ensure that they stay on course.
So I think this is just worth talking about and making sure that we provide people with a sort of heads up and from a personal experience though, long ago, 20 years ago, I’ve never forgotten that lesson or the one from before from, you know, a panel mount where we were off course and everything was saying it was OK. I think these are really worth lessons. Worthwhile lessons for us to continue learning.
Hope that’s helpful.
Bye bye.

Thanks Scott. That was great story and a real learning moment. As usual, system knowledge is a key component to a positive outcome. System failures happen and spoofing and jamming are changing the high reliability of aircraft so keep your head on a swivel and be as knowledgeable as you can.

 

In The News: Hydrogen Fuel

 

In the news in a part of the podcast where I talk about other happenings in aviation. A jet engine has run successfully using hydrogen fuel. The problem with burning hydrogen fuel is that it burns much hotter than jet fuel therefore the spray nozzles must be changed or calibrated to control and partially relocate the spray. A UK university in conjunction with Rolls Royce and their many partners used a Pearl 700 business jet engine for the trials and notably, full thrust was achieved. More trials are planned as are those with the Airbus group of companies. Hydrogen has three times more energy density than jet fuel, and when generated from renewable energy, hydrogen does not emit carbon dioxide.

Stay tuned for more news on that.

 

Thanks for listening and have a great day.

 

References

 

Rolls-Royce Runs Pearl 700 on Hydrogen Fuel

 

From Russia with love for Christmas: Jamming Baltic GPS

 

gpsjam.org https://ops.group/blog/outsmarting-gps-tricks-easy-solution-for-spoofing/

 

OpsGroup https://ops.group/blog/nat-crossing-after-gps-spoofing/


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