Airlines and 5G

[Mynnion]

I have not had a chance to research 5G in depth but I have to wonder why it appears to be such an issue with the airlines in the US but Asia has been using it for over a year.  Is there a real issue or is it being used as an excuse to cover for the other issues they have been experiencing?  Thoughts?

https://apnews.com/article/technology-business-dubai-middle-east-united-arab-emirates-bcac403626879062f8d07080f87e5880

[Mynnion]

I should add that Verizon and AT&T have been planning 5G for over a year and the first I heard about the potential airline issue last month.

[TheDrake]

The FAA has said it will allow planes with accurate, reliable altimeters to operate around high-power 5G. But planes with other altimeters will not be allowed to make landings under low-visibility conditions.

Among the problems that may make the 5G rollout an issue in the U.S. and not other countries, according to the FAA, are that American towers use a more powerful signal strength than those elsewhere, the network operates on a frequency closer to the one altimeters use, and tower antennae point up at a higher angle.

from your own article. Different frequency, higher power.

[alai]

As with pretty much all these "5G" stories, not a "G" thing at all, but a spectrum-bandwidth one.  (Well, those plus the "unhinged nonsense" stream, but the less said about those the better.)

[rightleft22]

United States are rolling out 5G service in a spectrum of radio waves with frequencies between 3.7 and 3.98 GHz and the aviation industry is worried that US 5G service is too close to the spectrum used by radar altimeters, which is between 4.2 and 4.4 GHz.
In Europe, 5G services use the slower 3.4 to 3.8 GHz range of spectrum. Also in Europe some countries restrict the placement of 5G antennas near airfields as well as power levels.

The question! If Europe knew and planed for the possible issues with 5G and Aircraft WTF wasn't that taken into consideration in the US? Why just as the mobile companies were going to turn it on is the first we hear of it?

[jc44]

Its been a known issue for some time - on the whole it seems to me that the frequency gap should be plenty if the altimeters are any good at all. My (probably biased) distillation of the argument goes: FAA is informed about the change, FAA says "if this goes though we would have to to recertify some altimeters", FAA recertifies 2 altimeters, FAA sits on hands hoping that the other side will give in and they won't have to do anything more, FAA realises that they should have got their finger out and threatens to ground everything in a last ditch effort to avoid doing something and/or spending money.

[TheDrake]

Its been a known issue for some time - on the whole it seems to me that the frequency gap should be plenty if the altimeters are any good at all. My (probably biased) distillation of the argument goes: FAA is informed about the change, FAA says "if this goes though we would have to to recertify some altimeters", FAA recertifies 2 altimeters, FAA sits on hands hoping that the other side will give in and they won't have to do anything more, FAA realises that they should have got their finger out and threatens to ground everything in a last ditch effort to avoid doing something and/or spending money.

Can't you put that on the airlines too? Airlines know this is going to happen and the altimeters on 40% of their fleet are not certified. They sit on their hands hoping that the other side will give in and they don't have to retrofit their planes. Then the shoe drops and they have to reroute the world because they didn't want to install compliant gear.

[jc44]

Its been a known issue for some time - on the whole it seems to me that the frequency gap should be plenty if the altimeters are any good at all. My (probably biased) distillation of the argument goes: FAA is informed about the change, FAA says "if this goes though we would have to to recertify some altimeters", FAA recertifies 2 altimeters, FAA sits on hands hoping that the other side will give in and they won't have to do anything more, FAA realises that they should have got their finger out and threatens to ground everything in a last ditch effort to avoid doing something and/or spending money.

Can't you put that on the airlines too? Airlines know this is going to happen and the altimeters on 40% of their fleet are not certified. They sit on their hands hoping that the other side will give in and they don't have to retrofit their planes. Then the shoe drops and they have to reroute the world because they didn't want to install compliant gear.

Fair enough, I'm convinced - I'm happy to spread the blame to the airlines :-)

[TheDeamon]

After bothering to look into this a bit further.

The Altimeters in question are only used for Instrument Landing Systems(ILS), it has little to do with collision avoidance with things like mountains in operations not involving an airport landing.

If the ILS cannot be relied upon, the aircraft will not be able to land if visibility is less than 1/2 mile, it would either have to loiter and wait for conditions to improve, or divert to an airport that has sufficient visibility.

Still comes back to people being aware this was coming for years in advance, and everyone expecting somebody else to take care of the issue.

[TheDeamon]

A further consideration is the matter that if the Altimeters in question are less than 20 years old, and they are subject to interference from 5G transmissions in the relevant spectrum. Either the Altimeter manufacturer, or the 5G manufacturer really screwed up in their production process.

That's RF selectivity I'd expect from a mostly analog and manually tuned system. I find it hard to believe that applies to either 5G cell phones for obvious reasons, or the altimeters being used on a commercial airliner, as such systems would be manpower intensive.

So all that being said, the telecom companies are probably correct. You probably have a better chance of winning the powerball jackpot multiple times by way of buying 1 ticker per draw, than the entire world has a risk of someone having a Commercial airliner crash because of 5G interference with their ILS altimeter.