Knowing German I read through the sources. This article is pretty misleading.

The [primary source](https://www.watson.de/leben/urlaub%20&%20freizeit/879935671-...) is a slightly clickbait article asking the questions: "Are AirTags allowed in checked luggage?".

They reached out to Lufthanse asking them. They responded: "Luggage trackers are electronic devices so they have to be turned off when the luggage is checked".

It is unclear wether they really understood how AirTags work and that they are not active trackers.

There are a bunch of other magazine echoing this response but I have yet to find an official statement by Lufthansa explicitly banning AirTags.

Translation of the cited statement by the Lufthansa spokesperson:

“Baggage trackers belong to the category of Portable Electronic Devices and are therefore subject to the Dangerous Goods regulations issued by the International Civil Aviation Organization for carriage in aircraft. Accordingly, the trackers must be deactivated during the flight due to their transmission function, similar to cell phones, laptops, tablets, etc., if they are in the checked baggage.”

This likely refers to the following regulations: https://www.icao.int/safety/DangerousGoods/

From the 2017 addendum no. 2:

“Portable electronic devices containing lithium metal or lithium ion cells or batteries […]

d) if devices are carried in checked baggage:

— measures must be taken to prevent unintentional activation and to protect the devices from damage; and

— the devices must be completely switched off (not in sleep or hibernation mode);”

Note that the AirTag batteries contain lithium.

So Lufthansa is merely citing the applicable ICAO regulations, which presumably apply to all civil airlines.

I think they're incorrect, but one would have to read all the regulations carefully to be sure.

I'm basing that judgement on this: https://www.icao.int/safety/DangerousGoods/Documents/Guidanc...

Part 2E makes a battery handling label exception for button cells, quote: "except that button cells installed in equipment (including circuit boards) need not be considered."

While this is packaging guidance, and not airline guidance, I expect it's the same rule, for the same reason.

This section makes it even more confusing to me, since I thought that the whole cell phone transmission restriction theater had been removed a few years ago. Was that only within the US and I've been violating EU regulations for years?

I don’t think this is about transmission. Rather, it is probably to reduce the risk of thermal runaway of lithium batteries, which can cause fire and explosion.

The regulation also states that such devices “should be carried as carry-on baggage”, that is, in preference to checked baggage, presumably so that the devices are less prone to damage, and cases of malfunction and fire will be more quickly detected.

Sure. But to that end, are button batteries known to be susceptible to thermal runway?

See for example here: https://safetyfirst.airbus.com/lithium-batteries-safe-to-fly...

That article, while interesting, does not address button batteries. Maybe I missed it. I found it interesting that you can ship any amount of lithium batteries as cargo.

Button batteries are a different type. They don't overheat when shorted.

Anything which has energy overheats when shorted.

I upvoted you anyway, because by design, button cells have limited potential to cause damage when they short. Yes, they heat up, but they have very little energy to begin with, and a large amount of metal surface area which keeps thermal runaway in check.

Thank you for answering my question 4 layers below where I asked it.

Funny how the “don’t ask a question online, be confidently wrong” principle applies here so perfectly. I love it.

All current *rechargeable* lithium chemistries are an issue, single-use is not. Air-Tags aren't going to start a fire.

Air tags don't have lithium batteries

Did you bother to check? AirTags doesn't have any battery by itself, they use replaceable CR2032, which are most commonly lithium. Although alkaline alternatives exist.

My bad :(

Is the cell phone transmission theater even lifted in the US? I still get asked to turn on airplane mode regularly (though Wi-Fi is okay)

Actually, 2G does interfere with aircraft communication, I don't think it is the case for other bands.

You may already have heard the interference. Just before the phone rings, you may hear some a characteristic beeping sound on your headphones or speakers. And guess what, pilots hear it in their headsets too, aviation headsets are just regular wired headsets. I fly small planes and I hear it regularly. No big deal, it won't turn off the engine or anything like that but it is still a minor distraction, and it may affect communication.

I remember about 20 years ago, after the usual announcements, the pilot clearly said something along the lines of "someone has his cell phone turned on, please turn it off, I won't move before it is turned off".

So no, it is not just theater, maybe modern aircraft have a way of shielding pilot headsets from passenger phones, or maybe it is less of a problem with the phasing out of 2G, but it has a real effect I experienced first hand.

I'm surprised that anyone who believe that any passenger could mess with airplane communications by not turning their phone off would accept to take that risk and board a plane at all :)

If a phone can take down airline communications, there is something wrong with the aircraft. These should be properly shielded lines.

There are now millions of hours of airline ops with phones on. It doesn’t cause any problems.

Also hot tip: the pilots are using iPads the entire flight too. With Bluetooth and wifi often linked to other gadgets.

- I specifically mentioned 2G networks which AFAIK iPads do not even have, not WiFi or Bluetooth

- It can't "take down" aircraft communications, but it can be an annoyance to the pilots, which can be a problem in an emergency situation. It is a little thing, but aviation safety is a result of a lot of little things. Accidents rarely have a single cause. For example the worst accident in the history of aviation: the Tenerife disaster where two B747 ran into each others during takeoff is the result of a long and improbable chain of minor problems, some of them related to radio communication. Cell phone interference won't be the main cause of an accident but it may be a contributing factor.

- Do you really need to have your phone switched on? It won't work at cruise altitude anyways, and during take off and landing, you probably don't need another distraction.

So yes, having cell phones turned off make a lot of sense, it is a rule that has a small positive effect on security with almost no downside since you can't use electronic devices during take off and landing for other reasons (distraction) and you can't use your cell phone during cruise either because the network doesn't support it.

So when has this actually happened? There is a roughly zero percent chance that on any given flight, instructions to disable your phones are followed 100%. So, I think it's reasonable to suggest that literally every commercial flight flown in the past 15-ish years has done so with some device onboard that isn't in airplane mode.

Given that - why aren't airplanes constantly falling out of the sky? If this is the situation on every single flight, why isn't what you are suggesting actually happening?

edit: a downvote isn't exactly an answer, and I think it's a fair question. If the assertion is that cell phones etc cause serious problems for aircraft operations, then why are we not seeing it actually happen? Or are we saying that everyone on the flight is, in fact, turning every single electronic device they own off, every time, every device, for every person?

What I meant is that we are not talking about absolutes here. There will be some cell phones turned on, sure, but the less there is, the less likely it is to become a problem.

And one of the reasons airplanes are not constantly falling out of the sky is that there are thousands of little rules and safety considerations at every level. Software, hardware, pilot training, ATC, and some of them affect passengers directly. For example one not so obvious rule is that the cabin lights are turned off at night during landing, the reason is to make sure the eyes of passengers are accommodated to a dark environment in case of an evacuation. Rules related to electronic devices are in that category.

Rules are much less stringent on general aviation, but general aviation is also much less safe than commercial aviation. Cessnas don't fall out of the sky constantly but they do it more often than Boeings. The ratio is about the same as motorbikes vs cars.

I repeat, cell phones won't make planes fall out of the sky by themselves! But if the plane is already in the unlikely situation where it is about to fall out of the sky, everyone needs to be fully alert to respond to the situation, and the authorities concluded that it is better without beeping cell phones. Has it saved lives? We don't know, but if we waited for someone to die to implement safety policies, we would have a lot of dead people.

The rules may change, in fact they are changing and cell phones are allowed in some flights, but please follow the damn rules, there are here for a reason even if it may not be obvious. Flying is intrinsically dangerous: deadly speeds, deadly heights and deadly outdoor conditions. And yet commercial aviation is one of the safest means of transportation, the likes of the FAA and EASA are doing at least some things right.

And on a more personal, subjective note: I think it is a good thing to disconnect once in a while.

Funny how people without actual first hand experience with the issue defiantly ignore then attempt to refute every point you made.

A lot of people are ignorant of spectrum allocation, and sideband interference. Twenty years ago I had an old Samsung flip phone (2G/3G). I could tell every time a text came in when I was sitting at my computer, because the speakers would let loose with a tell-tale 'bzzzt bzzzt bzzzt' before the phone could finish handling it and displaying that I had a text. The handshake with the tower would be picked up somewhere in the audio path.

OK so here's my first-hand experience. In the 20+ years that personal cell phones have been commonplace, zero flights have experienced an accident as a result of that cell phone use. The FAA has also walked back the ban on use of personal electronic devices.

I appreciate that you feel strongly about this, but the world has done the experiment millions of times over a couple decades. We do not have to wonder about the outcome, the work was already done. Nothing happened.

So, neither reality nor the current stance of the FAA are in alignment with your assertion. "Funny how people..." indeed.

> These should be properly shielded lines.

Hehe, why do you assume the lines are a problem, when the physical comms system ends in a big antenna? Of course modern airliners have wiring that is all “properly” shielded.

> It doesn’t cause any problems.

Isn’t that a funny response to a pilot’s first hand account that a problem exists?

Exactly. Maybe needs to be cross posted to r/confidentlyincorrect

Just so there's no confusion on this, the cell phone rule is FCC, not FAA. It's not about interfering with the aircraft, it's about causing problems with cell networks.

Well, they used to come scream at you if you were reading a Kindle during takeoff, so that part has relaxed at least

So far as I know you're supposed to put your phone into airplane mode to turn the cellular radio off, but they don't seem to care if you use bluetooth any more

The reason for that one I've heard from pilot friends is just that they want you upright and alert during takeoff and landing. I've been told to stop reading a book during a landing once. But imagine most of the flight crew don't want to deal with the potential fights from telling someone to put away a non-cellular device.

I seem to remember from "Cockpit Confidential" that things could get thrown around in the air during a bumpy landing, causing a risk of head injury to passengers. This includes books.

I'm usually playing games, reading or watching videos during takeoff and landing. Nobody has ever told me not to. Why would I need to be alert? Do they think I'm not going to notice if the plane suddenly starts falling off the sky?

> want you upright and alert during takeoff

I’m great at sleeping, so I sometimes fall asleep during taxi and before takeoff. That was never an issue.

I'm the opposite, basically never sleep on a plane.

But I've seen many people asleep during landing and turbulence, and can't remember a single instance of the attendants even attempting to wake them up. They would go open the windows and taking care not to bother them.

I don’t envy you, my wife is the same, so those long flights (Germany <--> South Africa) are pretty hard on her. And yeah, as long as you are visibly belted, they don’t bother you.

They are supposed to ask everyone stow devices over 2 lbs.

i fly exclusively delta, and i always get asked to turn airplane mode on and any services that transmit audio are explicitly banned while on board (Discord, teams, etc.)

> services that transmit audio are explicitly banned

Because taking a call is annoying AF to the 50-100 other people in the shared giant tube.

I’ve been seated next to people who insist im not on a call, this is FaceTime and I’ve always wanted to yell at them for their disrespect.

> Because taking a call is annoying AF to the 50-100 other people in the shared giant tube.

Then why did airplanes used to have built-in phones in every seat?

This hasn't been the case for over 20 years on most planes and the onboard phones were so expensive that only business or 1st class passengers would even consider using then. As usual, their convenience was valued more than everyone else's. I'm sure nowadays if a 1st class passenger got on a call over the in-flight wifi, the staff wouldn't bother them either.

With the ubiquity and generally reasonable pricing of in-flight WiFi, I'm actually a bit surprised that you don't see more people jabbering away. I've never bought WiFi myself and I suspect there are quality issues and I assume some ports may be blocked, but I haven't seen many people obviously on active calls at all.

Why don’t you?

If you have to ask this question, it is a sure sign you are not sufficiently socially calibrated to interact with other people on an air-plane. I advise you to invest time into better understanding your fellow humans by learning about psychology.

Yelling would be an overreaction, likely leading to further escalation and diminishing the chance of achieving the goal of stopping the maladaptive behaviour. GP acted correctly to suppress the impulse, I guess in the end he did nothing, which is the next best course of action. Adults are supposed to treat the problem situation in a calm manner and implicitly point out the established social boundaries (this works better if your personality is more masculine than feminine): interrupt the talking person and get his attention, kneel down to the same eye level, state clearly what can be observed what he's doing (having a conversation, perhaps talking loudly), what the effect is (annoying the other passengers), and remind him that calls are not allowed by the relevant authority (flight crew). Firmly direct him to end the call right now. Throughout the conversation keep stern demeanour, keep eye contact and the same level of volume when you speak.

If he complies right away, then mission fucking accomplished, requite by showing approval (nodding, making a slightly more friendly face), or perhaps even something expressing gratitude if that's appropriate in your culture.

The argument "not on a call, this is FaceTime" in an attempt to shift away from the central point of the conversation. Do not let him pull you into his frame. Simply ignore this sentence, keep referring to the call as a call. If he's stubborn, or ignores you, or wants to have a quarrel, then it is okay to metaphorically lose the fight. Walk away and inform the flight crew instead, it's out of your hands now. In the end, it is a certainty that you will win, even if the talking person turns out to be highly neurotic or narcissistic and throws a tantrum.

Pointing out disrespect is not likely to work, the talking person has already shown he does not care. However, shaming is more likely to work, it is a powerful social tool and it is very much appropriate to use here. You could say that all the people around are affected (insert hand gesture here) and they do not approve of what the talking person is doing.

What should not be done is body contact other than touching the shoulder to get attention; trying to take the headphones or mobile device; talking down (literally and figuratively). Do not ask, beg or demand, instead use the appropriate word that comes closest do instructing or directing, use the imperative verb form in your language.

> Firmly direct him to end the call right now. Throughout the conversation keep stern demeanour, keep eye contact and the same level of volume when you speak.

I'm not quite sure the other person is the one whose social calibration is off. This would be incredibly patronizing behavior unless you're speaking to a literal child. Besides, "Why don't you?" was obviously a throwaway half-joke.

Thank you. I legitimately debated on whether or not to respond, lol

I think that was the highest question to answer text ratio I've seen in a long time: 1 - 192

Don't ask a question you don't want to know the answer to.

Well, sometimes the question itself is intended as a DoS attack

I guess a form of https://xkcd.com/356/

The main reason for what you call "theater" is possible interference with ILS. And saying mobile phones or other devices are not in the same frequencies, does not cover the scenarios of misbehaving/cheap or uncertified devices.

"Instrument landing: why do all electronic devices need to be shut off?" - https://aviation.stackexchange.com/questions/11555/instrumen...

"Why aren't cell phones allowed to be used in aircraft?" - https://aviation.stackexchange.com/questions/2021/why-arent-...

MythBusters dismissed it a few years but forgot to consider misbehaving/cheap or not certified devices. And I would not trust two hipsters to be the certification committee for commercial airliners... -

https://web.archive.org/web/20140715091521/http://www.discov...

The more predominant issue is keeping anything with a lithium-ion battery in checked luggage. They'll crack down on anything from laptops to hearing aids.

CR2032 batteries that are in airtags are NOT lithium-ion, they're non-rechargeable and are usually Lithium/Manganese Dioxide [1] (lithium metal). I believe they're fine to have in checked luggage if contained inside some equipment (like the airtag). [2] Look for PI 970 If transported by themselves, they're cargo aircraft only.

Source: [1] https://data.energizer.com/pdfs/cr2032.pdf [2] https://www.iata.org/contentassets/05e6d8742b0047259bf3a700b...

The wording “containing lithium metal” from the ICAO regulation still applies.

That same org also explicitly calls out button cells are not being covered. They really aren't the same thing as a rechargeable lithium ion cell.

They're fine to have in checked luggage (under some restrictions). But the device containing them must be completely switched off, according to the rules. That is at issue here.

Both lithium-ion and lithium metal batteries that are installed in devices are allowed in checked baggage in the US and most other places. The devices must be powered off. What that means is a bit ambiguous as most modern laptops, tablets, and phones have some components powered any time a battery is installed.

https://www.faa.gov/newsroom/lithium-batteries-baggage

The regulation specifically states that "the devices must be completely switched off (not in sleep or hibernation mode)", and mobile devices normally all have a way to completely shut them down, with no components remaining active. The only exception I'm aware of are wireless earbuds (e.g. AirPods). Presumably you're not allowed to have those in checked baggage.

I would wager most people don’t realize that to completely turn off their iPhone they must adjust their settings to not use Find My even when powered off.

And to tell it somehow not to keep the clock running. Which of course is not possible.

So electrical engineers could just use a MCU let it power itself of during flight, use passive components (discharging capacitors) to trigger a wakeup after a set time and you are good to go?

> use passive components (discharging capacitors)

mechanical egg timer?

Definitely no problem with a ticking noise coming from your luggage.

Candle clock

Interesting. Since AirTags use standard CR2032 batteries, that means you could swap in an alkaline-based battery and avoid that regulation.

AirTags also have a two way bluetooth radio, which is prohibited: "due to their transmission function"

Where do you get that from? The citation says:

lithium metal

OR

lithium ion cells

OR

batteries

No, the wording is lithium metal/ion cells/batteries.

It's all cells and batteries that contain lithium.

Wording: "Portable electronic devices containing lithium metal or lithium ion cells or batteries"

I read the latter part as "lithium ion... cells or batteries".

It's read as

(Lithium metal or lithium ion) (cells or batteries)

So do cargo monitoring (temperature/tilt/vibration/tampering) devices, which are in a lot of commercial cargo - especially vaccine shipments, but any sort of sensitive equipment being air-freighted.

So do wireless earbuds, watches both smart and "dumb", hearing aides, sport sensors including chest heartrate monitors and bike sensors/computers, travel alarms, book lights, e-readers, keychain flashlights, film cameras, and probably a million other things Lufthansa has never cared about for several decades.

The vast majority of electronic devices are "soft" power now, and an e-reader with a 2000mah lithium ion battery is as "powered off" as an Airtag with a sub-3-gram battery. Airpods - no "completely" switched off mode, same for their case.

There's also never been a single case of an Airtag shorting or smoking or failing in any way that would endanger an airplane, and CR2032 batteries can't generate enough current, or contain enough energy, to pose a hazard.

For decades the airline industry had no problem shipping exothermic oxygen generators with little or no regulation (because it suited them well, as they needed to do so for logistics, as the generators are for emergency passenger oxygen) until it caused multiple commercial plane crashes. If you think Lufthansa is suddenly concerned about safety here, I have a bridge I'd like to sell you.

This is about them not wanting the public to see:

- that their luggage isn't on the plane with them, and generating a fuss at the gate / in the plane

- that their luggage is in a specific place/airport and come calling for it or say "I can see exactly where it is, stop lying to me, it's at airport _____, send it to me"

- their stolen luggage ending up at an employee's home, or the warehouse of a theft ring run by luggage handlers which the company is ignoring

- their "lost" luggage ending up at a warehouse where it is then sold by the pound to companies that sort through your luggage and ebay anything of value

They really hate that customers now have the power to see that they're being lied to and/or stolen from, and be held accountable.

Except that Lufthansa simply replied by citing a ICAO regulation - no more, no less. They have not "banned AirTags", they simply stated an existing regulation that applies to any aircraft.

Whether they actually enforce that regulation in any way remains to be seen, but they couldn't have given any other answer (or else risk being investigated by civil aviation authorities for not properly observing existing flight safety rules).

If you want to convince anyone that they should allow lithium batteries with some particular characteristics to be used in devices that are not turned on, you don't have to convince Lufthansa or any other airline, you have to convince the ICAO and/or national civil aviation bodies, since it's their rule that Lufthansa was citing.

This really should be a top level comment, as it’s spot on imho.

It would be spot on if Lufthansa actually gave a different answer for those.

I bet you if you call Lufthansa and say "I want to put wireless earbuds in my checked baggage" they will also tell you they need to be switched off.

Dear god, get a grip. Somebody asked Lufthansa specifically about AirTags and this is their response about AirTags based on current regulations. I'm sure if you asked about lithium-based whatever else, you'd get the same answer because the same regulations apply.

There's no FUD in this comment. It's right on target.

It's FUD because OP cannot possibly know that "This is about them not wanting the public to see". That's pure speculation, and it fits the FUD definition perfectly.

And given that United, for one, gives me the exact same information (as far as I can tell) in their app about the location of my checked luggage as their computers have, it seems unlikely that one of their partner airlines would explicitly scheme to prevent people from knowing where their checked luggage is.

As others have said, this seems a case of AirTags possibly don't comply with long-established rules for checked luggage but, like a lot of the rules for electronics on commercial airplanes, the letter of these rules is broken in various ways probably tens of thousands of times every day.

Lufthansa gave a non-answer, and there's nothing in their comment suggesting they've banned airtags in checked luggage. They will also have an impossible time enforcing it.

The site "covering this" is focused on creating travel content to push credit card affiliate links. They (like most) benefit from clickbait articles that will get picked up around the web, giving them backlinks to improve SEO ranking for a competitive niche.

I'm not super familiar with these systems, but don't they send out beacons using something like Bluetooth Low Energy or some similar protocol? That wouldn't be just passive and turned off unless something external powers it (like NFC could be argued to be).

(Which is not to say that it's therefore a valid argument by this airline, but the title seems accurate if the trackers are sending out signals actively and that's what's prohibited.)

What do you mean "active tracker"? As far as I know airtags have a battery and aren't passive devices.

AirTags doesn’t report its location, the iPhone or other iOS devices report nearby AirTags. That’s the difference between an active tracker that has its own cellular connection.

For aviation regulations there is no different between an active or passive tracker, the rules are not about takers.

The rules are about there being a lithium battery in it (there is) and whether it has a radio transmitter (it does, airtags transmit Bluetooth signals).

Lithium batteries are not allowed in checked baggage. Transmitters are allowed only if turned off.

Lithium button batteries of the size you would find in a tracker are allowed in checked baggage.

You are correct about transmitters though

It's not about the data but about the signal as such.

Don't the premises "AirTags are only allowed in checked bags if they're turned off" and "AirTags can't be turned off" lead to the conclusion "AirTags aren't allowed in checked bags"?

Sure. Just like a bazillion other coin cell powered nrf52 devices. Or like a coin cell powered digital watch. Would an F91-W be allowed in checked luggage? Perhaps not, not unless there is a specific exception. And if you ask some policy communication employee, they won't make up exceptions, they'll apply the rules at hand.

The battery can be removed.

But you're also not allowed to transport lithium based batteries in checked luggage unless they are inside a powered-off device, I believe.

I think you can as long as they are stored in such a way as to prevent an accidental short circuit.

Per FAA, this is correct. Obviously other jurisdictions may vary

https://www.faa.gov/hazmat/packsafe/resources/media/Airline_...

AirTags are pretty much active devices, they transmit data all the time. If some iPhone happens to receive that data, iPhone relays it to Apple servers and adds coordinates where it received data.

Best comment in this thread. This should really be about the article being a well executed recipe for clickbait.

They are banned: https://twitter.com/lufthansa/status/1578879849577385984

Note that the reason for airport mode is a courtesy to cell-phone carriers. It's not any air safety issue. Rather, 300-500 cell phones all trying to contact the next cell tower, multiple times per minute, would wreak havoc on cell service.

https://www.inverse.com/article/51015-cell-phone-use-on-airp...

At one point, when both cell phones and laptops were new, there was perhaps a risk to the airplane's electronics. Modern cell phones have been steadily tuned to reduce interference with other electronics though - good thing, otherwise you couldn't use them in a modern home with its dozens of connected devices. And modern avionics have been shielded to protect them from outside electronic interference - also a good thing, otherwise the next terrorist could simply turn their laptop on. The ban on electronic transmission is one of those regulations that was a response to technology at a particular point in time but now is largely vestigial. You can tell because it's rarely enforced, and yet bad things do not occur just because you forgot to turn your phone to airplane mode.

The term airplane mode will persist as an anachronism forever. Some day we will have to explain to our grandchildren why disabling networks has anything to do with airplanes.

It'll be in good company with dialing, film, photograph, watching the tube, etc.

Actually photograph was already out of date, because graph had morphed from "to write" to making any kind of image. Which itself I believe meant something akin to inscription /engraving.

Actually while photograph may no longer be a graph as in image on a surface, in some ways it's still an image impressed on rocks. Made using lithography. Have we gotten closer to its roots?

Don't forget floppy disks being enshrined as the Save icon - that has to be one of the shortest lives devices to give rise to such an anachronism.

And the fact that at that point they weren't even floppy anymore. Like 5 or 8 inch were...

The typical icon looks like 3.5", and inside the housing the disk is pretty floppy. In contrast to hard disk platters, which derive their name from the internal mechanism, not the housing properties. Otherwise they would be called storage bricks or similar.

I always kinda found that as a copout. Just so to keep using same name.

"And the fact that at that point they weren't even floppy anymore. Like 5 or 8 inch were..."

No, they were all floppy. You are just thinking of the hard plastic case that 3.5" diskettes had. If you crack it open and disassemble it, the actual spinning disk is just as floppy as the 5.25" was.

This is as opposed to a "hard" disk which is a hard platter inside a fixed disk.

I'm seeing various products switch to Cloud-related save icons, e.g. upload arrows, arrows going into a cloud, etc.

Maybe it's more complexity than needed, but I'd love to see us settle on arrow-to-cloud meaning "Save any changes" and the floppy icon meaning "Save a copy to my machine."

-graph effectively means recording, storing, so photograph is still very much valid and will forever be.

Yup, "photograph" is literally "light recording".

Yes, both γράφω (>graph) and English write seem to have "scratch, carve" as earliest senses.

My most frequent use of the airplane mode, is when I go underground on metro systems, which I find pretty ironic.

(Without Airplane Mode, the phone will keep trying to connect to cellular towers, which just makes the network experience unstable)

Perhaps "Underground Mode" would be more suitable in a modern context /s

Isn't an unstable network experience better than no network experience?

A lot of apps have cached experiences that they'll only show you if you have no network connection. If the app detects a very weak LTE connection, it'll try to load data over the network. That means that on a weak connection, I often end up being served nothing, rather than the data that's already cached on device.

As a tangent, I feel that a lot of these problems are fundamentally because engineers don't understand how poorly their software performs on unstable networks. Unless you live in a large metropolitan area with a well used underground transit network (in the USA, I suppose NYC would be the only qualifying city... sigh), you'd likely never experience these symptoms on a daily basis.

If I “download” music for offline listening in Spotify, in the highest possible quality, and I attempt to listen to that music on a unstable network, the app will not work. It will wait for me to completely lose the connection before playing the cached files. Have noticed similar bugs existing in other software

...or you live in a dense suburb where they never bothered to put up towers, or a rural area where towers are more scarce, or any where that you have to go in a building without wifi..

I don't honestly believe many developers don't experience this a lot. It's probably just such a transitory experience that it's not worth the rearchitecting required to really solve it.

I’d believe they don’t experience it at their desks at work. And they probably aren’t often thinking about work when they’re at home or visiting rural areas.

> Unless you live in a large metropolitan area with a well used underground transit network

Or anywhere more than ~50km from the nearest town. I dunno what coverage is like in the U.S. but in parts of Australia it’s not uncommon to lose reception when country driving.

"Isn't an unstable network experience better than no network experience?"

Yes, you would think ... but that is not the case.

QA and design of modern mobile apps and software - and even devices and appliances - neglects the testing of bad network connectivity.

Both my physical Sonos devices and, for instance, the apple-provided podcasts app, can handle being fully offline reasonably well. On the other hand, if you start dropping ~50% of packets they lose their mind and (in the case of Apples podcast app) freeze or crash.

It drains the battery really quickly in my experience. On my (admittedly old) iphone a 30 minute subway journey without airplane mode will drain about 10%.

Also even if i'm listening to music I have downloaded locally, Apple Music will do a system-wide popup complaining that it lost cellular connection. Sometimes in Safari a webpage that was downloaded at the station will suddenly erase itself and attempt to refresh itself upon losing connection. Those are usually the kinds of ad-ridden sites that are making nonstop ajax calls, but sometimes that's what i'm reading.

Not for apps like Audible which (this is my guess based on personal experience) prevents you from doing anything if you seem to have connectivity but can’t get a real response. Offline mode is simply more stable, unless you need to sync status from another device.

Audible is terrible for this. The parking lot at work is situated juuuust right to the point that when I'm leaving the office, my phone thinks its connected but has no actual connectivity. Audible sits there trying to sync the storefront and whatever else instead of just playing my damn book when I turn on my car to leave for the day.

Depending on what you're doing. Many apps that reach out to the internet at launch will hang if there's an unstable connection, but will recognize when there's no connection and open in an offline mode.

In my experience, no not at all, as it causes my phone to drain its battery exceptionally fast while it thrashes the modem in a frantic search for signal.

Yes! I don't know why nobody talks about this. If I don't go into airplane mode, half of my daily battery drain is from two half-hour trips in the underground subway. It's insane.

By far, my #1 wish for my iPhone would be a mode to basically "detect subway networks constantly changing" and just give up trying. Like, if it observes all cell and wifi networks disappearing entirely together with movement... then totally new ones appearing... every 45 seconds... just stop. And wait passively until there's some kind of heuristic indicating you're above ground, before trying to establish new connections with everything.

Obviously make this optional, but I turn on airplane mode every time I enter the subway and turn it off after I leave, just so I don't have to worry about running out of battery during the day otherwise in case I take 3-4 trips.

Very good ideas! As hobby I like to automate mundane tasks. I’m applying a similar approach by using iPhone Shortcuts app. See https://twitter.com/xiwenc/status/1578670843584204801?s=46&t... for how i did it by automatically turning off/on low power mode, wifi, etc. Perhaps you’re inspired by it.

Not if you're conserving battery life I suppose..

I find that my music/video streaming apps work a lot better with no network than with an unstable network.

In the Hong Kong MTR (subway) mobile phones work just fine. I was shocked when I couldn't get a connection in the London tube.

In DC as well, Verizon strung the tunnels with base stations. I get better cellular data on the subway than I do at home.

“Do do you know why radio silence on cell phones is called Airplane Mode?”

‘Because of the long historical association of activating that mode on airplane flights?’

“Well, yeah, but, like, it’s actually anachronistic, because it doesn’t really affect the airplane anymore if you’re transmitting.”

‘Okay, but, I mean, it is the mode that, even today, in 2060, most commonly comes up when you’re on a pla—‘

“Look, I was just trying to sound wise. Just let me have this one.”

“Grandpa, what’s an airplane?”

“Well Nancy, before instant interdimensional travel…”

Imagine physically traveling through a medium. I only transmit my bits instantaneously and get reconstructed on the other side.

Well, maybe. My kids seem to have taken it for granted that clicking on that weird square thing that we know as a floppy disk icon saves their work, somewhere. I don't think they ever asked why that symbol.

My iPad is forever in airplane mode. That way I can turn wifi off without iOS automatically turning it back on 24 hours later.

If you turn off wifi from settings instead of the control center (top right corner pull), it will stay turned off. If you turn it off from the control center, it will indeed say "Turning off WiFi until tomorrow".

Can you at least get from Control Center to the corresponding Settings page easily now (long press, hard press, etc), or is Apple dying on that hill?

> Can you at least get from Control Center to the corresponding Settings page easily now (long press, hard press, etc)

You can, just long press the wifi icon in control center, it will expand to show all wifi points nearby. Then click on "settings" button, and it will take you to the actual wifi settings page in the settings app.

This isn't a recent change btw. Idk when they added it, but I remember using it since at least iOS 13 or 14, which was 2-3 years ago.

Can only check on iphone, but long press on wifi, then again on wifi on the subsequent menu (where you can select which network to connect to) has “wifi settings” at the bottom.

Yes, but it's much easier to turn it on/off from control center, so I just have to leave it in airplane mode.

True. As an alternative, I personally just created a one-action shortcut for turning off wifi and assigned it to the double backtap action[0]. So i dont even need to look at the screen anymore or go into any menus. I just do a double backtap, and wifi stays turned off until i need it (same as doing it from the settings).

If you want, you can also just add that shortcut to lockscreen as well and do it via a single tap from there (which is also less clicks than even control center).

0. https://support.apple.com/guide/shortcuts/run-shortcuts-tapp...

Nice shortcut, thanks! I do love shortcuts. :)

Wow, this is amazing, thank you for sharing this! This was annoying me for years.

It only turns back on 24 hours later if you turn it off from Control Center. If you go to Settings > Wi-Fi, it will turn off permanently.

That and the same with Bluetooth is something that really grinds my gears with apple

I remember using a Nokia phone long ago that didn't have an aeroplane mode. It was simply called "offline".

I once forgot to put my cell phone in airplane mode during a flight from London to SFO (and didn't use my phone during the flight). I was rather alarmed to see a flood of text messages from my carrier welcoming me to Iceland, Canada, and the US upon my landing.

That sounds... Improbable. When you were passing over Iceland you must have been far too far above the antennas to receive any sort of signal, unless it landed there on the way across the ocean?

Can't speak for Iceland specifically, but can confirm that if you fly from Seattle or Portland down to SFO, you follow a corridor of fairly strong mobile coverage most all the way, and it's occasionally usable at cruising altitude for a moment here and there. Definitely enough to get text messages.

This is in fact the real reason that we still have the airplane mode restriction.

A phone at cruising altitude can see and try to connect to a huge number of cell towers at once. Like, orders of magnitude more towers than it would be able to see even from the top of a mountain. Plus, you're constantly disconnecting from some towers and connecting to new ones. This puts a strain on the cell network systems.

One person won't have a negative impact but then you multiply the problem by the number of people who fly daily.

Definitely possible, 100%. Can confirm getting texts at 25k feet while not in airplane mode. I was on a flight from JFK->SEA and got welcome to Canada texts above Toronto area.

I too have gotten similar sorts of texts on my last trans-Atlantic flight from DIA to Frankfurt.

Being 6 miles up and 8 miles horizontally is only 10 miles from a cellphone tower. As rural cells can easily be more than 20 miles this seems reasonable.

I would think the antennas on cell towers are polarized to limit radiated power up.

Curvature of the earth means that an airplane may be horizontal at 20+ miles out, while a surface vehicle is blocked by ground.

Not so much polarised as aimed. I'm not familiar with 5G (which I believe uses phased array beam aiming), but earlier generations had provision to physically tilt aerials in the vertical plane to optimise beam direction.

They are.

Would that do much for multi path bounces etc?

Depends on the base station. We usually point them down and try to adjust the power output not to "spray" the signal all over the place but rather be focused (and save operator costs), however some stations are set on max power and a lot can bounce away, indeed.

The bandwidth required for the initial handshake is very, very, very low. I'm not surprised that in areas with strong enough networks (especially considering there's no visual obstruction towards the skies) that a portion of the connection process would succeed, but it wouldn't be sufficient for anything else (thus the welcome SMSs only arriving far later).

A long time ago when we found out that iPhones were keeping track of where you went, I learned that my phone had associated with some Russian cell towers when I flew over Russia flying from Newark to India, or somewhere like that. It’s highly probable.

This also happens passing over Sydney to Auckland from Singapore.

Yep, flying Sydney to Perth occasionally passes over Adelaide and I’ll notice my phone change Timezone to Adelaide and get a notification or two come through

I have received messages over Russia (traveling from US to India, 2-3 years back). And I received from one more country that I do not recall. It happens.

I have AirTags in a case that is shipped by air a lot (without me being on the same flights) and once I got an updated location in midflight.

I was as surprised as you. We did not land. I do not have an explanation.

This happens to me, too, particularly when I fly in Asia. I collect screenshots of notifications welcoming me to countries I've never been to.

Had the same happen a couple of times on flights to Alaska from the US west coast. Surprised to see messages from Bell Canada

Switching your phone transmitter off is technically required by FCC regulations: https://www.ecfr.gov/current/title-47/chapter-I/subchapter-B...

Realistically there isn't an issue with leaving a cell phone on and out of airplane mode going purely based on how many people forget or ignore the directions everyday and how infrequently there are problems. But I'll make two points:

The idea that a cell phone transmitter can interfere with an airplane is by no means outrageous. Sure, a modern iPhone/Pixel/whatever has to meet certain emissions and interference standards. And modern airliners are designed with some interference rejection in mind. And ancient airliners from the 70s don't rely on a lot of electronic systems at all. As for airplanes designed in the 90s, well it's not silly to ask whether 200 people with 1W transmitters would interfere with the electronic systems. A properly functioning compliant phone shouldn't, but there's still some risk. Incidents do happen, though they are generally minor. I was on an airplane that had to abort a landing and go-around because they couldn't hear the tower over cellphone interference (voice comms are analog). Obviously no one died, but we were still delayed a bit.

It probably makes sense to relax the rules, but it is incredibly frustrating to see the attitude of "if they don't force me to turn it off it must be OK". The FCC requires you to turn off transmitters to avoid interference. The airline asks you to do so for the same reason. Experts in the field (myself included) are telling you there's a small risk and you should hit the airplane mode button. There's zero benefit to keeping your cellular service active in flight at all. But everyone's seen some article on Facebook (or in this case inverse.com) that says maybe there's a big conspiracy and everyone's lying to them. So they take a risk (albeit an extremely small one) with the lives of 200 other people. For no gain at all.

So do whatever you want, there's nothing I can do about human nature, but believe me when I tell you there's no government conspiracy to make you press the little airplane button funded by the cell phone companies. Yeah, the risk is probably negligible - it's just really hard to prove it and easier to make a small ask of passengers.

A few airlines (Etihad is one that comes to mind) operate mini cells on the plan and you can roam on a local 4G network and makes calls/use data. If I recall correctly it’s switched off on takeoff and landing but you can definitely use your phone on these flights.

> It probably makes sense to relax the rules,

I suppose this issue will actually fix itself with the advent of cheap Internet onboard the plane via WiFi, which combined with VoWiFi, will effectively switch cell off automatically when connected. People are more likely to use free WiFi onboard than to voluntarily remember to switch the Airplane Mode on.

Most places Lufthansa flies are not within the FCC’s jurisdiction.

I went on six flights this summer and on each one at least one person was talking on the phone during takeoff. The flight attendants didn't even say anything. I think this request has passed.

> Note that the reason for airport mode is a courtesy to cell-phone carriers.

This doesn’t track. What about trains?

Cell phone cells are (ideally) shaped to account for the expected pattern of how handover will occur. Along roads and train lines, the cells are (at least in GSM) supposed to be tailored to allow for easy routing and handover as the devices travels in the direction of the way.

While I have never read anything concretely analyzing the handover pattern of devices on airplanes, I would expect that since a very large number of cells are almost equally visible/equal signal strength, the network would have to frequently handover the device from one cell to another.

The handover process is, for voice traffic, very resource intense. (in GSM) it involves duplication of traffic to the neighboring cell and a lot of coordination.

I think that could be the reason for why mobile operators find airplane-borne devices annoying.

The cell tower network is designed to cope with devices located on the surface of the planet, i.e. where the geometry between the handsets and the tower is roughly two-dimensional.

I am also unconvinced that handsets on aeroplanes are really a problem for the network, but trains aren't the counterexample you're making them out to be.

Cell towers are designed for terrestrial users because their radios aren’t pointed at the sky.

Gogo provides inflight Wi-Fi in the US through its ground based towers and all the antennas are pointed at the sky :)

Flights (at least in the US) fly roughly a direct route, but ATC spaces out planes and small weather diversions are common. So it’s more like a band of coverage needed between cities. Also, the combinatorics of considering every US city pair that currently or has previously had commercial service between gets long. Then you would have to consider every route that an airline in the future may offer, even just seasonally. Then if you calculated the optimal route between each pair and figured out the width of the cellular coverage at 30,000 ft from a single cell tower below, I don’t think it would be possible to offer service to every domestic flight in the US without achieving complete coverage of the US.

China on the other hand has a limited number of very narrow flight corridors that all commercial aviation is restricted to because the majority of the airspace is government controlled. That’s the only nation I can think of that would have enough air traffic to justify terrestrial tower installation but whose domestic flights are confined to a such a small part of the airspace that it would be possible to provide service to all domestic flights without achieving coverage of all Chinese airspace.

That doesn't address the 2 vs 3D problem the person you’re replying to outlined.

Line of sight and curvature of the earth.

At 20 miles out, a device on the ground starts losing line of sight, at 20 miles out, a device on an airplane starts receiving horizontal line of sight.

This. Aloft, your phone sees many, many towers.

You're supposed to put your phone on airplane mode in a train or subway too, but most people don't:

https://pocketnow.com/airplane-mode/

The problem is significantly lessened for trains vs. planes though because you're traveling an order of magnitude slower and hence you switch cells an order of magnitude less frequently. Also many commuter rails run alongside major highways or boulevards, where the cell systems are built assuming lots of cell handoffs at roughly highway speeds. If enough people used high-speed rail to overwhelm the cell system we'd probably see announcements to put phones in airplane mode there too, but very few folks will travel long distances at high speeds on a train.

That article sounds like a bunch of hogwash to me. The CTA in Chicago specifically has cell phone infrastructure in the subway lines, and that predates that article.

https://www.transitchicago.com/cta-to-bring-4g-wireless-serv...

> You're supposed to put your phone on airplane mode in a train or subway too,

That's a pretty insane claim in most of the world. Lots of people expect and enjoy full coverage on train or subway rides. I work at a carrier and the signal strength and cell capacity on trains are part of the top metrics we use to benchmark the quality of our network and the customer experience.

> You're supposed to put your phone on airplane mode in a train or subway too,

Why would you be expected to do this when we don't require drivers to put their phones in airplane mode? I get that US trains are slow compared to other parts of the world, but does the Autobahn require airplane mode? Doubtful since my German car happily connects to my phone in multiple ways.

>> You're supposed to put your phone on airplane mode in a train or subway too,

> That's a pretty insane claim in most of the world.

So is this:

> but very few folks will travel long distances at high speeds on a train.

> If enough people used high-speed rail to overwhelm the cell system we'd probably see announcements to put phones in airplane mode there too, but very few folks will travel long distances at high speeds on a train.

Millions of people travel long distances on trains: 353 million/year on the Shinkansen network, 1.5+ billion/year on China high-speed rail, 110 million on France's TGV. These passengers use their phone without overloading the cell networks.

The operator can just pay for the high speed handover feature license ;)

It doesn't track in any way. In the airport there's small cells or femtocells by the operators. In the air, the only cells you can reach are the one pointing upwards.

Also, they don't really ask for airplane mode anymore, at least not when I'm flying.

Trains move significantly slower than planes. They're also on the ground, mostly below the towers, while planes are in the air, moving very fast, with multiple towers in line of sight.

Doubly doesn't track as airplane mode is often required during takeoff and landing, which barring controlled or uncontrolled flight into terrain usually happens at the airport, where you and the so many folks taking the same airplane as well as several other airplanes are not required to take their cell phone off as a courtesy to operators.

I can get the EM interference angle just fine, which stays (or stayed until recently) in place as a vestigial CYA rule of a time when cell phones were crude enough to be able to produce a spark which is what makes gas stations display a "no cellphone" sign to this day because back then it could ignite gasoline vapour.

Line-of-sight. If you're 4-5 miles up with no blockers except the aircraft skin, you get to confuse a lot of towers at once.

Must not be very much of an issue since there’s basically zero messaging around what airplane mode is for.

Not once has any of my carriers even said “please turn on airplane mode to help the network”. Instead it’s an in-passing recommendation made by air stewardesses so boilerplate it feels like superstition.

I wonder what the actual impact is and how that relates to the low effort messaging around airplane mode.

Most trains only go a tenth the speed of planes. And frequently much slower than that if they're making a lot of stops.

And movie theaters, malls, stadiums. Maybe I’m missing something?

Most, if not all, of the movie theaters I've been in have been fairly stationary.

Stadiums are actually challenging problems for mobile network builders. That's tens of thousands of people. 300 people in a passing airplane are not a problem. Computers are fast. 3MPH, or 300MPH no longer matters to mobile networks until you actually overwhelm the number of calls/connections you can pack into one place's infrastructure.

I used to live a few blocks from the AA Arena in Miami. I could always tell when a Heat game had just finished because my cell reception would drop to 1 bar or lose connection altogether. Then a few seconds later you'd hear the crowd of people reaching the parking lot right by my building.

If you're in a stadium travelling at 600mph, you have a heck of a problem!

I think the challenge isn't so much "lots of people in one place" as "lots of people travelling extremely fast with line-of-sight to hundreds of cellular towers at the same time".

Ideally mobile devices in theaters, malls, and stadiums aren't traveling at hundreds of miles an hour with a vantage such that they're in range of multiple towers simultaneously. It used to be (and maybe still is with 5G) that adjacent cells used different channel pairs. That way a handset at the edge of cell A could talk to both cell A and B to negotiate a handoff. Handoffs can happen pretty quickly.

If cells A and F are on the same channel pair and a handset can see both towers the tower the handset is not talking to just has a higher noise floor. It's like in an apartment if the next unit over is on the same WiFi channel.

You'll note that in older generation cell systems theaters, malls, and stadiums were terrible places for cell signals. Now many have micro/nano cells that cover much smaller areas to deal with congestion. Handsets reduce their output power when the received signal strength is better. So a handset will readily talk to a microcell at a stadium rather than try to talk to a tower further away (with a worse signal).

But for planes, hundreds of passengers hitting dozens of towers simultaneously on the same channel pairs would be rough on switching. Carriers need to know where in the network to route messages to handsets. If a handset is handing off to multiple towers quickly or worse hopping seemingly randomly to towers as a jet flies over it'll be difficult to keep it connected. Multiple that by thousands of people in the air at any given time. Areas near busy airports would have absurdly unreliable connections for people in the air and on the ground.

Compare the speeds of both modes of transport

Can we avoid this here and at least have one website where we focus on the technicals and problem being discussed vs. the Americans’ interjecting their current complaints?

Trains are what keep groceries on your shelves. They almost had general strike last week because the drivers only have 5 days a year not working. No weekends, no sick days, etc.

>> I don't think those are suitable for human transportation.

> Trains are what keep groceries on your shelves. They almost had general strike last week because the drivers only have 5 days a year not working. No weekends, no sick days, etc.

Are you trying to disagree? That sounds extremely human-hostile.

Dude, faux ignorance is rude and anti-conducive to useful conversation; please don't. (Unless, of course, you're sincerely unaware of trains being a widely used mode of transportation even in the States, in which case you're not rude but you should go ask Google to inform yourself.)

If this were a thread on ever declining US education outcomes, this comment would be relevant.

Please, just don’t.

Re: "Rather, 300-500 cell phones all trying to contact the next cell tower..."

That might have been a concern when 2.5G was cutting edge and HLR/VLR databases ran on Sun hardware of the period. Even then, hundreds of updates in a couple seconds was not a huge challenge.

Like a lot of what airlines tell customers, it is a self-serving version of reality, strongly colored for airlines' convenience and deniability.

If there was ever a shade of a possibility that a cellphone or other electronic device could interfere with the operation of an aircraft, they'd never even let you take anything like that onboard.

The whole "turn off your devices" thing is more about validating compliance and making people pay attention during the most incident-prone times of flight (takeoff and landing)

Before landing on the last flight I was on, the flight attendants requested that everyone turn off their phones (even if in airplane mode) due to the weather conditions while landing. Does anyone know what purpose that could possibly serve?

This was in France if that's a relevant clue.

The France clue actually contradicts my guess, because I'm guessing that was an Airbus? Anyways, he's one theory:

Boeing has an issue where its radio altimeters are affected by C-band 5G transmissions. I believe maybe the pilots were relying more on the precision of the altimeter because their vision was impaired due to the bad weather? The whole 'turn off phones' instruction could be because people would follow the unusual request to turn off their phones instead of just telling them to put it in airplane mode (which is so common that some people just don't bother)

Last flight I had from SFO->CDG was on a Boeing 737-800. AirFrance doesn't mean it's always Airbus.

They didn't mention it was AirFrance in their origninal comment, and when they said "in France", I assumed an intra-France flight. Many regional & LCC carriers in Europe operate Airbus planes exclusively.

If SFO is supposed to mean San Francisco and CDG Paris then certainly not. The max range of a 737-800 is about 50% of the distance.

It’s a 777

You're correct. Here's the plane we took: 777-300ER

https://us.trip.com/flights/status-af084/

I'm pretty ignorant of airplane models, Air France flight but it was a large plane so may have been a Boeing 777.

I think they meant because it's Air France and the EU generally tries to support Airbus (based in Europe) rather than Boeing (based in the U.S.) it seems likely that it is an Airbus aircraft

I understand-- I looked it up, and although they're only buying Airbus going forward, most of their 10-across fleet is still 777: https://en.wikipedia.org/wiki/Air_France_fleet

Probably because the pilots were going to be flying an IFR approach. (flying on just instruments through low visibility near the ground, a worst-case scenario for interference being able to cause a fatal crash)

Probably so that if there was an issue people are paying attention and not screwing around on their phones/listening to music

I’d interpret this as a “pay attention and be ready” rather than something from the phone itself.

Interference can be a serious problem for autoland https://avherald.com/h?article=445873f3/0001

Whether electronic devices inside the plane are such problem I don't know.

It's because they want people to be attentive if shit hits the fan during landing. Being attentive make you respond faster if you need to evacuate.

Although there have been some legitimate concerns raised about some 5G bands edging into altitude sensors https://www.icao.int/safety/FSMP/MeetingDocs/FSMP%20WG11/IP/...

I would argue the airlines and airplane manufacturers are far more at fault here.

The fact that aircraft systems are sensitive to frequencies outside their allocation is ridiculous. If literally anyone else was camping on frequency bands they didn't have the rights to the various regulatory bodies would be up in arms.

Sure, but base stations are going to be your main worry there, since they put out way more power than user devices and the antenna of a radio altimeter will be quite directional and pointing down.

TLDR; the aviation industry had a decent technical study done on radio altimeter interference from 5G and the FCC determined it didn’t show radio altimeter interference from 5G was likely. Then an aggregated summary of that technical data was shared with an aviation industry group (whose members include radio altimeter manufacturers), and that group used the aggregated data to claim any 5G use would likely lead to catastrophic crashes and multiple fatalities.

As a private pilot and software engineer interested in spectrum policy, I’ve been following this closely for years as it’s wound it’s way through the FAA. I have yet to see any convincing, reproducible evidence that any radio altimeters that are operating within specification (filtering out all signal below 4.2 GHz) have malfunctioned due to interference from 5G cellular signals. The one thing the FAA and airline industry claim as evidence is a study by an industry group (Radio Technical Committee for Aeronautics), whose members include radio altimeter manufacturers who would benefit from large retrofits/upgrades. The RTCA didn’t actually do any of their own testing, they received aggregated data from AVSI, a Texas A&M aerospace research group, which had done a study in 2019 on radio altimeters interference. In 2020 the FCC determined that AVSI study “does not demonstrate that harmful interference would likely result under reasonable scenarios (or even reasonably 'foreseeable' scenarios to use the parlance of AVSI)”. Then, two years later when the FAA went to the NTIA (National Telecommunications and Information Administration), which is the agency tasked with managing federal spectrum and agency spectrum disputes, and demanded they stop the FCC from letting carriers turn on networks in the C-band, the NTIA refused because its own technical experts had already evaluated the technical data that RTCA used as evidence that any 5G use of 3.7 GHz - 3.98 GHz band would cause interference severe enough to cause a catastrophic crash resulting hull loss.

Also, when this whole fiasco unfolded neither Verizon or AT&T had spectrum even close to the radio altimeters band. Of the C-band spectrum (3.7 GHz to 3.98 GHz) that was auctioned off a few years ago, only Block A which is between 3.7 GHz and 3.8 GHz was being used. So in addition to the existing, and potentially larger than technically required, 220 MHz guard band between 4.2 GHz (where radio altimeters start) and 3.98 GHz, when the airlines were threatening to cancel service to the US and the FAA was waging a PR war against the FCC the spectrum in question was 3.7 GHz - 3.8 GHz. Even if Verizon and AT&T rolled out 100% of the 5G spectrum they had the ability to use in 2021, it would have meant 5G cell service was within 400 MHz of the radio altimeter spectrum. The entire allocated band for radio altimeters is only 200 MHz (4.2 GHz - 4.4 GHz). Additionally, other countries like Japan have cellular providers operating in 4.0 GHz - 4.1 GHz. Japanese aviation officials (unlike the FAA) actually configured different types of 5G equipment and radio altimeters and tested them, including to see the minimum guard band needed. They found 60 MHz was the minimum guard band needed and therefore the “standard” 100 MHz guard band would be fine. They also found you shouldn’t install 5G towers directly below the approach path of an airport, but that even high powered 5G base stations won’t interfere with radio altimeters if they are 200m away.

I think by far the most comprehensive explainer for this whole saga is by Harold Feld of public knowledge, which if you’re not familiar is a nonprofit advocating for an open internet which includes white papers and FCC testimony on spectrum policy they view as beneficial the public, such as allocating more of the federal government, specifically the military’s, huge bands of essentially unused spectrum. It’s on his personal blog. https://wetmachine.com/tales-of-the-sausage-factory/what-the...

sounds like I’ve been had by Big Altimeter :’)

I would say right about now is when you'd get your bag for helping to create a market for radio altimeters, but I think they exclusively do kickbacks in Spirit Airlines miles.

I’m a bit skeptical, bullet trains swamp towers too, they just put more towers along the tracks.

For bullet trains, it's worth to invest for train users. For airplane, it isn't.

Users benefit, too. You phone uses a lot more power when trying to connect to all those towers.

They don't appear to have GPS. Rather they contact local Apple devices over Bluetooth, and those devices know where they are. But then they don't have cellular access either, so this discussion is moot.

I mean, let's think this all can work.

You turn it off at $ALTITUDE. When do you turn them on ? There's no button and it is powered off.

luckily this happens all the time since people often forget. i know i do.

> At one point, when both cell phones and laptops were new, there was perhaps a risk to the airplane's electronics.

There was never any risk. Someone wrote an article in the times suggesting "perhaps" and people freaked out.

There has never been a single instance or study to support this claim. The entire idea airplane mode is a farce.

There definitely was theoretical risk with 2G-era mobile phones, which blasted considerable amounts of radiation.

I was in university once doing a signal interference lab: we had set up an circuit and we're trying to induce current in it from another circuit. Suddenly the oscilloscope on the receiving end showed a couple of wild spikes, and I received a text message on my trusty Nokia 1611: apparently 900 MHz was in the sweet spot.

Yeah , my car's radio used to go nutty when my old Cingular flip phone would check in with the network or get a call.

Yep, it was a common sound on PC speakers in the early 2000s: https://m.youtube.com/watch?v=FYjs7vsaSEw

This was a really fun sound when my guitar amp would pick it up

Ahhh, memories.

Oh wow, that brings me back a ways...

Actually, a single phone can easily cause a plane to crash.

Source: This is a lie but sitting behind someone on a plane who gets a call is super annoying.

I don’t think that’s true, or at least how you worded it is bad. Events of thousands of people don’t make you turn off your cell phone, so it’s not because of traffic to a tower. Instead, it’s interference caused by altitude and the pinging of towers.

It’s actually an FCC regulation that requires it, so it’s not a courtesy as you say.

> I don’t think that’s true, or at least how you worded it is bad. Events of thousands of people don’t make you turn off your cell phone, so it’s not because of traffic to a tower.

First of all, if you've ever been to an event with hundreds or thousands of people (such as a parade or a rally), you'll notice that even though you have "full bars", your service is degraded beyond usability, and you'll receive text messages hours late.

But in this case, the issue is that people's phones will be trying to connect to many different towers in short succession, as the plane travels.

Are you trying to tell me I’m wrong by repeating what I said?

> Instead, it’s interference caused by altitude and the pinging of towers.

In 2013 the FCC started a regulatory preceding to evaluate allowing the use of mobile phones on airplanes, because currently there is an FCC regulation prohibiting cellular mobile phone use while a plane is in the air. in 2013 the FCC also said there were no technical reasons to prohibit their use in flight. But the preceding was ended in 2020 with no rule-making because of opposition from pilots and flight attendants.

47 CFR 22.925.

https://www.law.cornell.edu/cfr/text/47/22.925#:~:text=Cellu....

Thanks, TIL.

I guess I'll continue to ignore that law :)