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Comment by Sporktacular | Hacker News Reader

1) The wifi system is EMC certified and tested with the flight instrumentation. Dozens of different consumer devices are not.

2) Lufthansa "allows it during the entire flight without restriction – even during take-off and landing unless the crew instruct otherwise"(https://bluetoothtechworld.com/can-i-use-bluetooth-headphone...). In other words, unless you're told to turn it off in the event of some problem, which is something you can't do when it's in the luggage hold of the aircraft.

Again, the articles specifies this is about EMC.

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Their wifi system might be, but a 100 phones and tablets, some from reputable manufacturers, some from "10TB tablet apple samsung iphone" sellers from aliexpress, and the system still works.

Imagine planes falling down because a single passenger had a malfunctioning phone on it... the lawsuits against boeing/airbus would be astronomical.

Not sure what about my comment you take to be an endorsement of opaque, seemingly unreasonable EMC rules. I don't make them, know if they work or particularly care for the purpose of this thread. The concerns stated, justified or otherwise, were about RF emissions and not battery fires.

Oh yeah, I guarantee that's on all the emergency checklists. "Ask very nicely if all the passengers can turn off their bluetooth headsets".

Also, I'm pretty confident that Lufthansa's Airbus and Boeing planes are the same as everybody else's Airbus and Boeing planes. If there was an EMC issue that they were running into from Airtags, it would have been jumped on by the national aviation administrations so fast your head would spin. It would be major international news. It would not be an obscure rule with misleading and contradictory guidance coming from a single airline.

I suspect the difference is more about the spectrum in use. Airtags can be found and interact via Ultra-Wideband (UWB), which essentially means low power broadcast across 3.1GHz up to 10GHz approx. This includes some spectrum used for GNSS.

One is probably fine but a hold full of them and people's iPhones emitting on UWB also?

By contrast Bluetooth, WiFi etc use the ISM radio bands, which can simply be avoided by any transmission the plane itself needs to do.

UWB, which is pretty new, would be a really good explaination of why they single out these trackers specifically. Without some solid test results to clear them, it's understandable why airlines might be nervous.

Would just add that it's more what the aircraft needs to reliably receive (not transmit) that is susceptible to local sources of spurious RF.

Yeah agree, receive is probably what I should have said :) I did try to see if there were any discussions of UWB before posting, but only found some PDFs from the FAA from 2015 or so in my casual search. I guess industry insiders might know more. It could well be that the low power was deemed not risky enough (you would have thought all airlines would have banned them if risky) and other posts suggest that in fact Lufthansa have not banned airtags at all... so who knows.

Is that certification actually important?

It seems to me like a denylist would be more useful than an Allowlist at this point.

Almost no consumer electronics are dangerous to a plane

Apparently, to them, yes.

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