Lufthansa bans AirTags in checked luggage

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.

I’d be interested in that guide if you could find it.

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.

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.

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...