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Comment by oatmeal1 | Hacker News Reader

The world is astoundingly safe that these sorts of thing don't happen all the time. Anyone who could light a cigarette could start wildfires all over California and many other places during the summer. Anyone who can buy a GPS jammer could disrupt one of the busiest airports in the world. With all the misanthropes out there you'd think chaos would happen more often. Glad it doesn't.

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> Anyone who can buy a GPS jammer could disrupt one of the busiest airports in the world.

Fortunately, that one is not quite the case – the aviation industry is incredibly safety-conscious and does not allow relying on GPS exclusively.

For both en-route navigation and landing, every plane will have at least one fallback system available (usually ground-based radionavigation aides such as VORs or DMEs or inertial navigation systems, which is also what was used for navigation during ocean crossings before there was GPS), and in fact, these other systems are seeing more use than you might assume: https://www.thedrive.com/the-war-zone/17987/usaf-is-jamming-...

GPS interference can, and has disrupted airports. The incident last year in Dallas where there was 24 hours of significant GPS interference of unknown origin disrupted operations. And while GPS is not safety critical, the interference degraded the operation of many different systems that provide additional layers of safety.

https://www.gpsworld.com/what-happened-to-gps-in-denver/

  The advisory also said the Wide Area Augmentation System (WAAS) and
  Ground-Based Augmentation System (GBAS), both designed to make
  navigation with GPS more precise, as well as the ADS-B collision
  avoidance and traffic management system, would be unreliable.
  
  Pilots reported other systems affected such as transponders that help
  radar controllers keep track of aircraft, traffic alert and collision
  avoidance (TCAS) equipment, autopilots, electronic flight bags and
  terrain warning systems.

https://www.bloomberg.com/news/articles/2022-10-18/faa-warns...

  Flights into the Dallas area are being forced to take older,
  cumbersome routes and a runway at Dallas-Fort Worth International
  Airport was temporarily closed after aviation authorities said GPS
  signals there aren’t reliable.

https://rntfnd.org/2022/10/18/faa-warns-airline-pilots-as-gp...

  Stanford researchers have determined that the interference event
  lasted 24 hours, though it took the air traffic system another 20
  hours to reset and recover.

From another incident:

https://www.gpsworld.com/nasa-report-passenger-aircraft-near...

  A report filed with NASA’s Aviation Safety Reporting System and
  published in June outlines how a passenger aircraft flew off course
  during a period of GPS jamming and nearly crashed into a
  mountain. Fortunately, an alert radar controller intervened, and the
  accident was averted.

Landing is moving away from ILS towards GBAS (TLDR computed corrections for high precision local positioning in 4D space within ~30km of the install), provided over unencrypted VHF.

https://www.faa.gov/about/office_org/headquarters_offices/at...

https://gssc.esa.int/navipedia/index.php/GBAS_Fundamentals

https://aerospace.honeywell.com/us/en/products-and-services/...

Unencrypted does not mean that the plane avionics will just accept any input without performing plausibility checks.

Even for "plain" (i.e. unaugmented) GPS, there's countermeasures, starting from simple physical ones (e.g. directional antennas leveraging the fact that GPS satellites are usually located above the airplane and not below or inside it), up to complicated logical filters checking all inputs for plausibility and rejecting suspicious signals and resulting position fixes.

Galileo even supports message authentication, which thwarts everything other than (very sophisticated) real-time signal relaying attacks: https://berthub.eu/articles/posts/galileos-authentication-al...

Subverting the positioning is different than denying the capability entirely through a higher power transmitter. If you require precise positioning to land and don't have it, kinda moot whether you're faking messages or overpowering. During VFR, not a concern. During IFR, low viz, etc, that is where capability loss is potentially material.

https://www.cnet.com/culture/truck-driver-has-gps-jammer-acc...

(aware of military receivers that can receive jam resistant signal, but that is not what commercial applications have access to)

True, which is why almost all airports have multiple different types of approaches, including ILS (which is directional and very high power transmitters in a specific location to jam).

The possibility of a large-scale GPS outage or jamming event is definitely a threat scenario that's being considered by aviation safety agencies. For example, here's the FAA's approach for en-route navigation redundancy, which includes maintaining enough VORs to ensure that there's at least one within every 100 nautical miles: https://www.faa.gov/about/office_org/headquarters_offices/at...

Yes, denying augmented GPS capabilities will probably impact operational efficiency significantly, but it shouldn't endanger safety.

I was watching the most recent 74 Gear video and there was a graphical demonstration of how pilots are reliant on GPS while taxiing.

Sure, I believe that in the air, GPS is redundant. But what Kelsey explained is that, before GPS and graphical maps, pilots on the ground would rely on paper charts that were manually updated and placed in huge binders. They would scour these paper charts to understand what taxiways they needed to take across the airport to get from gate to runway and back again.

Nowadays, the pilots have a nice screen where an image of the airport is displayed underneath a nice arrow depicting the aircraft in its GPS location and velocity. It's more difficult to get lost now, because you can see at a glance on the screen where you are. Looking outside your windows can often confuse, and fog and darkness and unfamiliarity can confound someone who is already lost.

The issue on 74 Gear was that someone got lost and thought they were in an entirely different location, when actually they had intruded on an active runway while just trying to taxi. A very dangerous situation, as you can tell.

I believe that, if GPS were jammed and unavailable, pilots would possibly be able to fall back on these paper charts, that is, if they are even being maintained anymore, but it would be error-prone, and any taxiing pilot would need to exercise utmost caution not to get lost like that.

For taxiing they use GPS just as Google Maps for driving, but it is mostly for pilot convenience to look at a screen and taxi than to look outside at the taxiway markings which in some poor visibility conditions are hard to spot and without the GPS they would I guess require a Follow Me car.

Regarding the runway incursion scenarios, you need to pay attention to the lights on the taxiways, because runway entries are highly illuminated and visible even in really low visibility conditions. You just don't enter an active runway by mistake.

"Paper charts" as you call them, are physical charts of airpots maps akin to a city map. And as a pilot you are required to know how to read and use those maps. Just as with SID/STAR charts. Pilots are expected to know how to fly using only basic instruments (airspeed, altitude, attitude, vertical speed, compass, banking), and even with some of those not operational.

Long story short, GPS jamming at an airport is an inconvenience rather than something critical.

Many large airports have high-precision ground surveillance radar for that very reason, and the software interpreting it can often issue automatic runway incursion warnings, operate visual “safe to cross” indicator lights etc., all without relying on GPS.

There is definitely responsibility on the pilots to not take a wrong turn, and that job gets harder without precision navigation systems, but more than one thing normally has to go wrong for a runway incursion to occur, as far as I understand.

The incursion that Kelsey was demonstrating happened at a very small airport, in fact, and indeed, several things had gone wrong.

All the people who refuse to go into airplane mode on a plane.

The TSA misses huge percentages of weapons during the passenger hand luggage searches in repeated blind testing.

This means that the standard movie-plot methods of hijacking aircraft are ridiculously easy to carry out: just bring weapons on a plane. There's only a 50% chance you get caught.

This means approximately no one wants to hijack airliners.

> The TSA misses huge percentages of weapons during the passenger hand luggage searches in repeated blind testing.

Between TSA missing most weapons while compulsively stealing cash, travelers would be far safer from genuine harm if the the agency didn't exist.

ref: https://reason.com/2021/11/19/after-20-years-of-failure-kill...

ref: https://duckduckgo.com/?q=tsa+seizes+cash

I just learned: It seems that state efforts to maximize gun possession have led to so many guns in airports - even TSA agents are starting to find them.

ref: https://www.forbes.com/sites/suzannerowankelleher/2022/11/01...

I suspect weapon and gun aren't the same thing here. I've accidentallied a ton of knives through TSA checkpoints because they're small and don't show up well against a my giant ball of cables, adapters, and chargers. OTOH, guns tend to be extremely obvious on x ray machines. They, at a minimum, have a fairly heavy steel barrel and the ammunition is solid lead and/or copper which looks like an extremely dark pattern of dots on an X ray. The springs also tend to stick out very strongly as they have a regular pattern and show up well. I'm sure they missed them before, but generally speaking I doubt it's something an attacker can even begin to count on.

Disassembling a firearm and sticking it's parts inside other regular carry-on items would be sufficient to get past most TSA screenings.

I was blown away with my first First-Class flying experience. You go through all this TSA security theater, and then they hand you a real metal steak knife and glass stemware shortly after take off.

You don't even need to bring weapons, they give them to you.

TSA stuff is all for show. It makes some people feel safer that they had to take off their belt or something...

You'd still need ammunition and the individual parts still look pretty striking. With a modern polymer firearm you're just going to see the slide and barrel assembly anyway. Go look up some pictures of firearms in luggage, they're pretty obvious even if you just consider the individual parts.

A barrel inside a curling iron, the spring inside a hair dryer, the slide inside a laptop, the frame does have small metal bits but, depending on their scanning tech, probably wouldn't appear much like a gun.

You probably don't even need bullets honestly, just the visual aid.

You don't even need a gun though, a knife is plenty lethal on it's own and readily available inside the terminal and even on the plane.

The TSA is blind tested on firearms specifically. They miss lots of them, like 40-70% in various tests.

Have you seen the kinds of people they put in that job? The whole thing is a farce.

I accidentallied a big knife I had in my bumbag (fanny pack) onto an international flight. And then managed to leave it in the seatback pocket by mistake.

I didn't ask for it back.

A repeat of the 9/11 attack became impossible before that day was over. It relied on the passengers and crew cooperating with the hijackers until it was too late: they would think that the plane is being diverted or held for ransom and the safest thing to do would be to go along, because that's how hijacking worked from the 60s through the 90s. But now everyone knows about 9/11, so everyone will fight like hell to prevent the plane from being taken over, because the assumption has become that if the bad guys get control everyone will die, and if the hijackers claim otherwise no one believes that.

The bad guys know this: they figure an attempt to do a 9/11-style hijacking will result in failure and death without doing damage to anything but the plane itself. No flying into the Capitol or the Pentagon in a blaze of glory.

Due to procedure changes, and very tough doors into flight deck which are generally locked, and voluntary handgun carry by pilots, US hijacking is not feasible. Yet we pay a ticket surcharge to get TSA groped and our privacy violated.

Americans won't see the enemy which is staring at us. Domestically it will have to get a lot worse over the next decade.

So it turned out to be ...

the hijack to end all hijacks?

"Never attribute to malice that which is adequately explained by stupidity" – Hanlon's razor[0]

Apart of some war zones or crime holes the world is quite safe and hospitable in general if one doesn't do stupid mistakes or really ask for problems. Every society has some form of agreed laws which try to correct a harmful behavior against them.

Accidental radio interference or setting fire can happen out of simple stupitidy or incompetence.

[0] https://en.m.wikipedia.org/wiki/Hanlon%27s_razor

The existence of that simplification is however often exploited. A lot of malice gets dressed as stupidity. Its also especially easy when stupidity is triggered maliciously.

Most people have easy access to do a lot of havoc if they just wanted to. Drive into a sidewalk full of people, push a bunch of people onto an oncoming metro train car, there are so many ways that we don't even need to get into anything that needs technology.

A lot of wildfires are caused by fires that are improperly extinguished, which can be cigarettes. Sometimes it's even fireworks.

July 4th consistently has the highest amount of human-caused wildfire. https://www.reuters.com/graphics/USA-JULY4/FIREWORKS/klvygax...

Up until a point anyone with a knife could hijack a plane and fly it into a building.

Ceramic and plastic knives exist and could easily be smuggled aboard an airplane. I think the key insight is that most people don't want to do mass harm and instead just want to live in peaceful freedom and do their own thing.

They literally give you a metal steak knife if you sit in First Class.

Terror Cell can't afford First Class? Just walk to one of the restaurants inside the terminal and take a steak knife before you get on the plane.

The TSA shenanigan's are wild... security theater on an entirely different level.

now the pilots have learned that if there's a person with a knife aboard the plane, they won't open the cockpit doors to avoid a potential hijacking and more casualties. And passengers know that if hijackers take control of the plane, the hijacker might crash it somewhere instead of holding the passengers and crew hostage, like it was done with plane hijackings before 9/11 and might fight back.

So with the example of the 9/11 attacks, the situation has changed enough that a plane hijacking with a knife is much more unlikely

Hijacking? Yes. Causing mass death and terror? No.

That really has nothing to do with being on airplane though, does it? There are endless places where you can get within stabbing distance of a group of people.

I'd actually expect a plane to the one of the absolute safest places, because like others said, everyone on that place has just become a victim. It doesn't even matter if you like the person being victimized, you're gonna exploit that distraction and beat the fuck out of the dude.

In public people are much quicker to just run away and keep themselves safe.

Humans are born selfish but also social. We're wired _against_ doing these kinds of things. And even when someone has a desire to cause mass harm, fear and self-interest usually stop them.

I liked a comment a few days ago about hostile actors on the internet versus meatspace:

"I asked about the security systems governing walking around in the hallway - was there any physical impediment preventing one person from punching, kicking, throwing a rock at another? Of course not - the security is socially constructed. Norms, consequences, etc, that on balance seemed to work out pretty effectively. I tried to make a case that security inside a local network of the size and scope of our school board was also ~90% social construction, but the student really struggled with it. There was a strong belief that because it was computers, you were expected to exploit it if it were vulnerable."

https://news.ycombinator.com/item?id=37279333

There was a time you could just walk around with a radio receiver and spy on everyone's phonecalls (IMEI stingray). Iirc it's not possible/that easy anymore with LTE.

AFAIK you can still do passive IMSI sniffing, which isn't full content but is quite interesting metadata.

Yeah, I’m going to need a write up/video on this…

(Not saying you’re lying, I just want to learn more!)

I'll do you one better:

For GSM, basic IMSI sniffing: https://github.com/Oros42/IMSI-catcher (usable with cheap SDRs)

For LTE, basic IMSI sniffing: https://github.com/JiaoXianjun/LTE-Cell-Scanner (usable with cheap SDRs)

For LTE, full-on sniffing of all unencrypted metadata: https://github.com/SysSec-KAIST/LTESniffer (generally requires fancy SDRs with GPSDO)

Can vouch that the first and second repos definitely worked as of about a year ago, but haven't personally tried since then. I don't have a USRP X310 (yet!) so can't personally speak to the fancy one.

Yes, $9353 is beyond my hobby budget. https://www.ettus.com/all-products/X310-KIT

stingrays just force the device down to 2G and capture that

Do/could SIM cards prevent this downgrade if 2G isn’t provided by your local provider anymore?

I know my Canadian SIM card somehow hides US providers from network scans, possibly with some geo or if/then rules (but visible from my EU SIM that tries its darnedest to latch onto the US networks and avoid the Canadian ones at all costs)

Android has a toggle in the settings to disallow 2G (except for 911 calls).

And yet the outdated, unsecured 2G protocol/hardware still exists in 2023, is it really a question as to why it's still in operation.

The way I see it, seems law enforcement agencies using stingrays have a vested interesting in seeing 2G alive and well.

many phones disable this

The plot of the next James Bond movie that is. And just for fun, its villain will slowly scratch their fingernails over the blackboard.

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