FCC vs FAA Story

There was a lively thread on NANOG about the FCC and FAA conflict over G5 spectrum and altimeters when it all came to a head early this year. ProPublica published an investigative report on it last week,

https://www.propublica.org/article/fcc-faa-5g-planes-trump-biden

Whaddya know. Plenty of blame to go around. Government regulative bodies captured by the industries they’re supposed to regulate. The usual stuff.

It appears that Crist Clark <cjc+nanog@pumpky.net> said:

ProPublica published an investigative report on it last week,

Inside the Government Fiasco That Nearly Closed the U.S. Air System — ProPublica

Whaddya know. Plenty of blame to go around. Government regulative bodies
captured by the industries they’re supposed to regulate. The usual stuff.

That piece has way too much inside baseball and misses the actual question
of whether C band radios would break radio altimeters.

Harold Feld did a much better job in November:

https://wetmachine.com/tales-of-the-sausage-factory/what-the-eff-faa-my-insanely-long-field-guide-to-the-faa-fcc-5g-c-band-fight/

R's,
John

John Levine wrote:

It appears that Crist Clark <cjc+nanog@pumpky.net> said:

ProPublica published an investigative report on it last week,

Inside the Government Fiasco That Nearly Closed the U.S. Air System — ProPublica

Whaddya know. Plenty of blame to go around. Government regulative bodies
captured by the industries they’re supposed to regulate. The usual stuff.

That piece has way too much inside baseball and misses the actual question
of whether C band radios would break radio altimeters.

Harold Feld did a much better job in November:

What the Eff, FAA? My Insanely Long Field Guide to the FAA/FCC 5G C-Band Fight. – Wetmachine

Well... a bit better look at the politics & motivations of the folks involved. Still doesn't address whether or not C band radios break radio altimeters.

Miles Fidelman

It’s nice to see the FCC take regulating receivers seriously, finally. It’s a two way street and we’ve only been looking one direction the whole time.

The discussion reminds me of the early 1990s, when mobile phones became pocketable.
There was some talk about how emissions from mobile phones that people take into cars could be bundled inside the car in unfortunate reflections and theoretically trigger airbag systems, hurt drivers and cause fatal accidents.

We know how that went.
(I got screamed at by taxi drivers more than once at the time while making phone calls in their cars. Needless to say, I didn’t manage to kill any of them.)

Safety is about probabilities. A theoretical possibility that occurs 0.01 times during the lifetime of the universe would be reasonably recognized as safe. Of course, most people (including politicians) can’t compute (and don’t understand probabilities anyway), so we will see some technically unjustifiable compromises that will appease the uninformable public.

By the way, the largest probability for influencing radio altimeter operation is likely to come not from the ground installations but from passengers using C-band-capable (3.x GHz 5G, e.g., band n77) devices on board… But addressing that would inconvenience the airlines, so it won’t be weaponized in the current attempt to squeeze 5G operators for money to replace crappy old altimeters that don’t work right with even a 220 MHz guard band.

Grüße, Carsten

It appears that Miles Fidelman <mfidelman@meetinghouse.net> said:

Harold Feld did a much better job in November:

What the Eff, FAA? My Insanely Long Field Guide to the FAA/FCC 5G C-Band Fight. – Wetmachine

Well... a bit better look at the politics & motivations of the folks
involved. Still doesn't address whether or not C band radios break
radio altimeters.

To translate from the FCC-esse: “Air industry, we cannot screw over
the U.S. deployment in 5G by taking the single largest, most useful
allocation of 5G spectrum off the shelf indefinitely because a handful
of older, crappy altimeters might under some wildly improbable set of
circumstances experience harmful interference. While we take air
safety issues seriously, you guys are gonna need to recognize that “no
5G in lower C-Band” is not a realistic expectation. So please work
with the wireless industry here to figure out if you are going to need
to get people to upgrade their equipment.”

Also this link from the article, which is self-serving but I believe
their numbers are accurate:

https://www.5gandaviation.com/

R's,
John

The problem was that when those older radio altimeters were built, no one else was near their frequency. So their sensitivity to near frequency interference was not as tightly tested as newer equipment is tested. It was possible that a near frequency could interfere with its operation at lower altitudes.

Replacing older equipment in airplanes is not just a matter of replacing them. When they replace them in commercial airliners, they MUST test each type of the equipment, in the plane ($$$ per hour) and make up and test new flight manuals, what happens if that piece of equipment fails in flight manual section instructions, ...

I think the FAA needed more time to test the old equipment in flight, and thus needed money for those expenses. Newer equipment is already tested to tighter tolerances and is safe.

They had 5 years, and did NOTHING. No amount of time would have changed that.

Shane

It is not that simple. And they have done a lot of work. Much more than NOTHING.

These are primarily used in low visibility situations. How many crashed passenger filled planes would have been acceptable?

Low visibility, low altitude flying is known as IFR. (IFR - Instrument Flight Rules). There are a hundred or more low altitude flight 'plates' published. They had to be checked, verified, determined to be safe. This is NOT something that they just decide. Until they knew it was safe, they had to tag it as unsafe. Below is an example of just two at the Van Nuys that MIGHT have been effected.

They actually have to fly each change to each plate, under different conditions to re-certify them. And you want them to do that. If they determine that it was safer if 50 foot higher in one segment, then they had to re-test again and then release a new 'plate'.

And they had to certify the equipment, done by the manufacturer and the FAA. They can't just place the equipment on a test bench and see if it still works.

We don't know, so go ahead and fly your 500 passengers in low visibility and see if you crash is NOT how to do it.

Two Kinds of Instrument Approach Charts

They had 5 years to do that, and didn’t start until the very last minute.

Hi,

Harold Feld did a much better job in November:

What the Eff, FAA? My Insanely Long Field Guide to the FAA/FCC 5G C-Band Fight. – Wetmachine

Right. From his article:

But in any event, in the face of rules adopted by about 40 or so other countries,
the aviation industry needs to show why the U.S. is different.

And if he did *any* real research at all:

In most of the world, RAs are not affected by 5G, because 5G signals most commonly
radiate in the 900MHz, 1.8, 2.3, 2.5 and 3.5 GHz bands, leaving a safe 800MHz
between 5G and RA bands. However, in the USA, demand for high-speed data on
cellular devices has led to the Federal Communications Commission (FCC) auctioning
additional bands in the C-band range between 3.7-3.98 GHz, only 200 MHz below the RA
band.

And here are some actual test results: https://www.rtca.org/wp-content/uploads/2020/10/SC-239-5G-Interference-Assessment-Report_274-20-PMC-2073_accepted_changes.pdf

All of that, combined with the real world deaths of people who died as a result
of radar altimeter failures, suggest to me that Harold Feld did not really do a
much better job in November.

Thanks,

Sabri
Licensed pilot since 2010

And here are some actual test results: https://www.rtca.org/wp-content/uploads/2020/10/SC-239-5G-Interference-Assessment-Report_274-20-PMC-2073_accepted_changes.pdf

People who understand radios don't think much of that report or the similar AVSI one. If its claims were true, planes would be falling out of the sky before anyone turned on a C band radio. See, for example:

Look, we understand that altimeters are safety critical equipment. We also understand that after the FCC's little experiment with self-regulation at Boeing, they're ultra cautious now. On the other hand, you probably saw that after a string of apocalyptic warnings earlier this year about shutting down all air traffic the FAA said, well, actually, the altimeters in every plane flying commercial routes are OK.

Five years ago everyone knew that C band was coming. A reasonable response would have been for the FAA to work with the FCC to figure out which altimeters might be affected (old cruddy ones, we now know), and come up with a plan and schedule to replace them. If the telcos had to pay some of the costs, they would have grumbled but done it. If the replacement schedule weren't done by now, they could live with that, too, so long as there were a clear date when it'd be done.

Instead the FAA stuck their fingers in their ears and said no, nothing can ever change, we can't hear you. Are you surprised the telecom industry is fed up?

Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly

Five years ago everyone knew that C band was coming. A reasonable response would have been for the FAA to work with the FCC to figure out which altimeters might be affected (old cruddy ones, we now know), and come up with a plan and schedule to replace them. If the telcos had to pay some of the costs, they would have grumbled but done it. If the replacement schedule weren't done by now, they could live with that, too, so long as there were a clear date when it'd be done.

The FAA could have easily ordered testing to determine which RA models were affected and issued an AD prohibiting their use after a certain date. Once that data was in hand, manufacturers could start working on STCs for replacements and the airlines could add those STCs to their next annuals, just like they did for ADS-B. Both would have a decent case for demanding that the telcos pay for it, and the telcos probably would have paid up. But that opportunity was wasted.

Instead the FAA stuck their fingers in their ears and said no, nothing can ever change, we can't hear you. Are you surprised the telecom industry is fed up?

Exactly. The FAA wants more delays while they do the work they should have done five years ago, but sorry, that’s not how politics works. The number of daily 5G users is orders of magnitude larger than the number of daily airline users, so the FCC *will* win this battle.

Stephen
PPL ASEL/IR

Five years ago everyone knew that C band was coming. A reasonable response would have been for the FAA to work with the FCC to figure out which altimeters might be affected (old cruddy ones, we now know), and come up with a plan and schedule to replace them. If the telcos had to pay some of the costs, they would have grumbled but done it. If the replacement schedule weren't done by now, they could live with that, too, so long as there were a clear date when it'd be done.

Instead the FAA stuck their fingers in their ears and said no, nothing can ever change, we can't hear you. Are you surprised the telecom industry is fed up?

The US phased out leaded gas for everything but planes by 1996, and you still can't get an STC stating you can use an alternative fuel for some engines 24 years later.

Here’s the problem

FCC ignored the rest of the world and EU’s 5G deployment in the rest of the world 5G base stations have half the EIRP of their US counterparts and the antenna systems use downtilt so 5G coverage on the ground is better and RADALT operation is largely unaffected except for helicopters in physical proximity to a base station.

5G/RADALT compatibility is only a problem in the US because of how the usual suspects decided to deploy the C band 5G base stations.

Had the US followed global 5G best practices we would not even be having this discussion, US carriers wanting to deploy as few towers/base stations as possible is the proximate cause for this mess.

As a result we’ve degraded Aviation safety and US has a poor 5G experience compared to the rest of the world a worst of all worlds scenario.

I’m a pilot(with a radalt in a small plane) and 5G user objectively my 5G experience is worse than 4G speed wise and i have a top level plan and because the areas ONLY 5G tower is near the only towered airport in my area i can no longer rely on RADALT for approaches in IMC minimum conditions to that airport.

Great job FCC i have poorer cell service and bad IMC conditions now means diverting to another airport and this is New England where the weather changes every 5 minutes and has done since forever enough so over a century ago Mark Twain wrote an essay on New England weather.

[replying to both to reduce the number of mails]

Instead the FAA stuck their fingers in their ears and said no, nothing can ever
change, we can't hear you. Are you surprised the telecom industry is fed up?

Of course, I'm not surprised. But, remember one thing: this is the government
messing up. One branch pitted against the other. As an innocent citizen, I could
not care less: the government effed up.

Exactly. The FAA wants more delays while they do the work they should have done
five years ago, but sorry, that’s not how politics works. The number of daily
5G users is orders of magnitude larger than the number of daily airline users,
so the FCC *will* win this battle.

The FCC might win a battle, or even a lot of battles. All it takes is one downed
aircraft with crying families all over CNN, followed by an NTSB investigation
which only needs to mention 5G interference with RAs, and I will bet you $50 that
ambulance chasing lawyers will sue everything and everyone connected to the 5G
debate that even remotely advocated rolling out 5G over concerns for passenger
safety.

Or, of course, the FAA will really play dirty politics and ground aircraft fitted
with certain RAs during a holiday weekend. Watch how quick public and political
opinions can shift. Remember, most privacy invading laws usually pass with the
"for the children" and "against the terrorists" arguments.

Sorry, this aircraft is fitted with an altimeter which may be subject to 5G
interference, thus we have to cancel your flight. You know, for the children.

Thanks,

Sabri

Hi Sabri

The flight cancellations are already happening, now if weather threatens to make a RA required approach necessary at an airport covered by a 5G NOTAM the flight is frequently cancelled.

Have you not noticed that during inclement
weather this year the number of cancellations has vastly increased over previous years

Airlines have no desire to deal with the ambulance chasers and if they can avoid the possibility by cancellation of flights they will do so.