Airlines Threaten to Ground Many Passenger and Cargo Flights Over Cell Operators’ Refusal to Change 5G Plans

Nothing like a good Godzilla v. Mothra fight, provided you are not caught between them. This one, showcasing airlines and wireless operators over 5G, is set to blow big on Wednesday. Major airlines are threatening to wreak havoc by cancelling passenger and cargo flights that they deem to be at risk of 5G interference. Remember the reason people do something as crazy-seeming as getting into aluminum canisters that fly at >30,000 feet is the airlines’ safety record, which is the product of relentless checks and controls. It took only two Boeing 737 Max crashes to have the FAA lose its status as global regulator of US-made aircraft, a position it may never recover.

Wireless carriers thumbed their noses at the airlines’ request not to deploy 5G transmitters within 2 miles of airports. The airlines did win two delays and some concessions around 50 major airports, but not what the airlines deemed to be a sufficient course change from Verizon and AT&T, who are set to launch their 5G services on January 19. The network operators apparently figured that the two of them having spent $68 billion on spectrum and having a captured regulator gave them the upper hand.

What AT&T and Verizon have missed is air travel and transport are a hell of a lot more important to American commerce than whiz bang cell phone speeds. As Paul Maud’Dib said in Dune, “He who can destroy a thing has real control of it.”

Reuters published an exclusive on the revolt of the air carriers. From its piece:

The chief executives of major U.S. passenger and cargo carriers on Monday warned of an impending “catastrophic” aviation crisis in less than 36 hours, when AT&T (T.N) and Verizon (VZ.N) are set to deploy new 5G service.

The airlines warned the new C-Band 5G service set to begin on Wednesday could render a significant number of widebody aircraft unusable, “could potentially strand tens of thousands of Americans overseas” and cause “chaos” for U.S. flights…

The Federal Aviation Administration (FAA) has warned that potential interference could affect sensitive airplane instruments such as altimeters and significantly hamper low-visibility operations.

“This means that on a day like yesterday, more than 1,100 flights and 100,000 passengers would be subjected to cancellations, diversions or delays,” the letter cautioned.

Airlines late on Monday were considering whether to begin canceling some international flights that are scheduled to arrive in the United States on Wednesday….

Action is urgent, the airlines added in the letter also signed by UPS Airlines, Alaska Air, Atlas Air , JetBlue Airways and FedEx Express. “To be blunt, the nation’s commerce will grind to a halt….

United Airlines late Monday separately warned the issue could affect more than 15,000 of its flights, 1.25 million passengers and snarl tons of cargo annually.”

The wireless networks contend that the US carriers are being unreasonable because 5G has been deployed overseas with no airline mishaps. But they know this is a bogus argument; the US spectrum abuts the air carriers’ frequencies, which is not the case elsewhere. As vlade pointed out on an earlier post about this row:

Well, looking at this USA has its own 5G bands, unlike the rest of the world (except for the super-high frequencies, where it’s joined by Japan and South Korea).Maybe there is a good technical reason why the US has to have the spectrum not just close the to altimeter one (4.2-4.4 GHz), but in fact overlapping?

Reader prof confirmed:

But the A4A said the issue remained unresolved as of December 30, with only days remaining before 3.7 GHz license 5G operations are set to start. According to the A4A, the FCC failed – since the beginning of the C-band proceeding – to explain why it rejected evidence of the “detrimental impact of interference” from 3.7 GHz licenses on radio altimeters

And as we had pointed out in our previous post, from a comment on AVWeb:

Unfortunately, as people who have been graced by the magic that is RF on a personal level, from the HAM down the street to the engineer in the lab testing the gear, have learned: just because you want to be transmitting on one set of frequencies doesn’t mean you aren’t also transmitting on a whole host of others. Furthermore, old equipment is not designed with constraints nobody had ever thought of at the time in mind.

Mass-produced, cheap RF devices are among the worst offenders, and with 5G base stations deployment being estimated in the millions by the time the rollout is “complete” to get good coverage, the only way for this huge infrastructure deployment to remain profitable for the carriers is for the equipment to be cheap and installed quickly. Cheap means likely QC issues, which mean a lot of unwanted emissions (including pop-fly spurious emissions) are likely. Installed quickly means people aren’t going to be going around doing field strength surveys to make sure the antennas aren’t aimed such that they’re bouncing or even emitting something straight up on the final approach to your local airport. While it isn’t likely to be a constant issue that renders your radar altimeter visibly wonky any time you fly over a 5G coverage area, it has been demonstrated by lab testing that there is a good probability that there will interference given the sheer number of interactions and, take this one seriously; the environment the avionics were designed to operate under – was definitely not a world covered in millions of kiloWatt range ERP transmitters broadcasting with massive bandwidth 24/7, 365.

The last standoff took place in early January, when AT&T and Verizon said they would not push back their January 5 5G launch date and the airlines threatened to get an emergency injunction. As we can see, the wireless carriers delayed for two weeks but otherwise appear not to have ceded much ground.

I assume the carriers will go to court but will also start implementing shutdowns. And if the courts do not move fast enough, this mess will fall in the Biden Administration’s lap. It is over my pay grade as to whether Biden has the authority to use an executive order to curb the AT&T and Verizon, or whether only the courts or Congress can sort this out.

One upside if the airlines and cargo carriers go into partial cessation of operations: it ought to sink Mayo Pete. Just imagine what the Republicans could do with this fiasco if Buttigieg were to become the 2024 Democratic presidential nominee.

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  1. Maritimer

    Here we do have a civil war: one captured US Government regulatory agency battles another for profit on behalf of the industries by which they are captured. Meanwhile, Big Pharma with it captured CDC, FDA, etc. savages other sectors of the American economy for loot. America’s industries looked at the 2008 disaster and Wall Street bailouts/non-prosecutions and said: “Why not us?”

  2. Eric The Fruit Bat

    IIRC, deploying on the ultrawide bands (n261), which don’t penetrate most infrastructure (hence their very slow deployment), not to mention the carriers would have to have several hundred thousands of sites. The Ultrawide band is in the 30-40 GHz band. Spurious harmonics is such a bear to fix.

  3. vlade

    To avoid confusion. The 3.7GHz lincese mentioned in the other comment (by prof) is really 3.7-4.98 GHz license, overlapping the altimeter frequencies of 4.2-4.4 GHz.

    If say only part of the spectrum (say 3.7-5GHz) was used, it’d likely be no problem, as half a GHz gap should be more than sufficient.

    1. John Zelnicker

      vlade – Please check your numbers.

      It looks like the figures in your parenthetical “(say 3.7-5GHz)” isn’t much different from the figures in your first sentence “3.7-4.98GHz”.

      Of course, I may be missing something, as I know almost nothing about RF.

      1. vlade

        You’re correct, I meant 3.7-4GHz in the parenthesis. That would leave a gap between 500 and 200 MHz, which should be plenty to avoid interference.

        1. Yves Smith Post author

          As indicated, US experts don’t necessarily agree given the caliber of US consumer equipment. Current cell phones similarly do not have spectrum overlap with airplane systems, yet their use is barred on planes in the US and I believe abroad too.

          1. bob

            ‘Airplane mode’ is seen as a way to turn a phone off. All it does is stop a phone from transmitting. It can and does still ‘listen’ without interfering with RF.

            My guess on why is that whomever is in charge of ‘location services’ wanted it that way so they could still track phones and give people a false sense of security.

          2. Oh

            Previously, airlines had their own phone service on board which cost a bundle per minute. I wonder if that was the reason they didn’t allow the use of cell phones. Now they have their own WiFi hot spot for which they charge $$. Is that another reason?

            1. Yves Smith Post author

              You still can’t make calls using airplane WiFi. Use of the cell phones is verboten and there haven’t been phones on planes for over 10 years, so that isn’t a motivator.

              I use WiFi on planes, and my perception based on who is bitching when it isn’t working is that it is 100% the laptop crowd trying to get work done.

              I’ve also left my phone on by mistake, and gotten messages only upon landing. So my experience (admittedly with an older phone) says there is no signal at altitude, but that is presumably not what the airlines are worried about. It’s just after or before landing when any interference could really matter, and they can’t police passengers when the assistants are strapped in for takeoff and landing.

              1. Synoia

                Cell Manufactures and Phone service providers do not send signal vertically, because few of their Human customers can by themselves

                The redaction pattern of cell sites is designed for earth-bound humans.

                I built a passive reflector for the cell frequencies, and it did not work. Getting RF at that frequency to work is mare like black magic than science.

  4. Larry

    Yves hit the nail on the head, the airlines provide a real critical service and it’s disruption will be immediately felt by vast swathes of the population. If the airlines and their regulator act accordingly with their power position, I don’t see how they can fail. They have all the leverage. If the carriers have to eat their stupid investments in 5G, so be it. Nobody will pay it any mind.

    1. Russ

      Don’t worry if the carriers have to eat their investment, they will be at the gov’t slop trough for their reimbursement. Taxpayers will bail them out.

    2. marku52

      “But I can’t get my cat video to load!”
      He complains, as a 737 crashes into his house.

      One of these things is not like the other…..

  5. Verifyfirst

    Bizarre. What possible difference would it make to the wireless carriers if they did not put up these new transmitters within 2 miles of any airport? Travelers have somehow managed to survive at the current bandwidths in airports.

    Seems the wireless carriers would also have a liability exposure, if a plane crashes etc. because of this new interference, of which they had been warned?

    And was it the federal government that sold this bandwidth that overlaps with aviation?

    1. Ken

      The carriers will have no liability, the FCC blessed this long ago. Ajit Pai led the push over all objections. He has landed his golden parachute as a partner at PE firm Searchlight.

      Note he is a former Verizon employee, Obama nominated him to the FCC, Trump made him the Chair.

  6. pebird

    Sounds like a workplace safety issue for pilots. Joe can dust off the OSHA executive order and cut/paste COVID for 5G.

  7. Jeff N

    I wasn’t suspicious of 5G until our state passed a law preventing all local govts from regulating it.

  8. danpaco

    Its taken a lot longer than expected to upgrade all of the NSA surveillance gear to be compatible with 5G.

  9. Matthew G. Saroff

    I am inclined to believe, much like wireless microphones in the past, that the equipment on airlines does not conform to the FCC specifications. (Wireless microphones used analogue TV frequencies illegally)

    There is plenty of space in the spectrum, radar altimeters are blunt instruments that put out a fair amount of power, and it works fine in Europe.

    If I were a cynic, I would think that the airlines want to use this to extract rents from the cellular companies.

    Oh, wait, I AM a cynic.

    1. Yves Smith Post author

      Except you miss, as I mentioned in my earlier post but neglected to restate here, that the cellular companies have kinda-sorta not entirely disagreed with the airlines’ concern. They’ve said the airlines should upgrade their altimeters to get out of the way of the C 5G spectrum. That would be a massive undertaking since it would have to be done across a huge number of airplanes as well as ground equipment, and either done simultaneously or else have redundant capacity installed. Given how extremely scarce cockpit real estate is, I would assume that’s a non-starter.

      I further neglected to mention that pilots might also sick out, either encouraged by their unions, or out of their own concern, which would make matters even worse.

      This problem won’t be solved by a monetary payoff. The airlines want 5G away from airports. And the airlines are already getting huge life support payments from governments due to Covid.

      1. disillusionized

        Even that wouldn’t work given that foreign aircraft would be extremely peeved given that they have managed to resolve this issue. The real question is, why in God’s name wasn’t the FCC told to stay out of what’s presumably an international standard frequency set designated to aircraft?

        1. Ken

          FCC does the telling, there is no higher authority in the US on spectrum allocation and enforcement. They have abandoned the reason they exist to serve their corporate masters. To be sure, their corporate masters are the ones looking to monetize the spectrum, not the ones utilizing the spectrum for safety.

          1. Yves Smith Post author

            Oh yes there is. Congress. And the courts.

            Regulators only implement statute. Congress can rewrite the laws. The courts have also and not infrequently overturned regulations and enforcement actions. Look at how SCOTUS just overturned the OSHA rules on the Biden mask mandate. Many many many other less prominent examples.

    2. BillS

      If a nearby transmitter is operating near the operating band-edge of the radar altimeter we can get
      1) desensitization of the radar altimeter receiver front end (its low-noise amplifier or frequency-conversion system). preventing its operation, (can sometimes be corrected by ensuring sharp band-edge rejection in altimeter receive filter).
      2) possible spurious adjacent channel emissions from the 5G transmitter can degrade radar altimeter receiver performance (e.g. raising noise floor, false radar returns, etc. Filtering in altimeter cannot correct this.)

      I imagine that airlines have justified concerns for the safety of their planes and passengers with regards to this problem. I say this as someone who periodically designs aerospace instruments in his day job.

      1. vlade

        Out of curiosity, what is “near the operating band-edge”? 100MHz? 200MHz?

        I’m far from a pro, but I’d be really curious to understand what would one need for a safety band. Say 5G channel width is IIRC at most 100 MHz.

        I don’t think that for cell phones there would be any serious leakage (at the powers used, around 200mW or less) for more than another 100MHz.

        I have no idea what powers aerospace instruments operate on, I’d assume is much higher than mW, but I have no idea how much they assume/don’t assume leakage in their own design. I.e. if it transmits at X, what width of spectrum it’s actually checking for reflections, and how much of that width is already covered in the allocated spectrum (i.e. if you have a spectrum starting say at 4.2GHz, can you transmit at 4.2GHz, or do you have to be a bit off?).

        1. BillS

          A guard-band of 100MHz is reasonable and the required filtering is not so onerous. Generally speaking, sharper filter roll-off means more cost and weight. The problem is that radar altimeters use relatively low transmitter power, since they transmit and receive at the same time. Ground reflectivity is not that high as well, so radar returns are not strong. Altimeters usually do not work more than a couple thousand feet above ground. (See, for example, this. ) The altimeter receiver has to operate with a really loud transmitter close by. Generally, the altimeter relies on the separation between receive and transmit antennas to reduce its own self-interference. Any added interference from external sources can become problematic.

          Generally, the receive filters in the altimeter are good enough to reduce close-by signals to with safe limits. The problem is mainly unintentional radiation from consumer devices, since often manufacturers try to skimp as much as possible on electromagnetic compatibility measures to keep costs down (altho’ the devices need to satisfy regulatory requirements on emissions, which may or may not be sufficient). There is also the issue of possible malfunctioning consumer devices that can emit undesired radiation (e.g. a device damaged by dropping that still works, but shielding of a critical area may crack or a ceramic filter could break, allowing radiation in problematic band).

    3. Synoia

      The RF spectrum in the US is differently allocated than the rest of the world’s allocations.

      Comparisons with Europe’s spectrum allocations is not valid.

  10. Tom Stone

    This fight is a bonanza for lobbyists, teen hookers of all genders and coke dealers.
    And don’t forget that a planeload or two of passengers dying spectacularly contributes to the GDP almost instantly.
    It’s all good.
    Because markets.

  11. voteforno6

    One minor quibble – I thought Mothra was the good monster in that fight? Does that mean that the FAA is the good guy here, or are they just less bad than the FCC?

      1. John

        Godzilla-Mothra monsters fighting. Think simile or metaphor. Never having seen the G V. M flick I had no idea who was “good” or “bad” so it worked for me.

  12. George Phillies

    ” if Buttigieg were to become the 2024 Democratic presidential nominee.”

    He was already secretary of transportation during the ongoing ship container crisis, during which time he went on paternity leave.

  13. Andy

    Long-time reader, first-time commenter here.

    I work as an independent analyst covering the wireless industry and claims of safety issues are baseless.

    The current licenses have a minimum of 220MHz guard band between C-band and altimeter frequencies but the upper portion of that spectrum won’t be deployed for a couple of years at least. The deployments scheduled for tomorrow are for the lower portion and will have 400MHz of separation (the initial US launch uses 3,700-3,800MHz and the altimeter bands start at 4,200MHz).

    Meanwhile, Japan is using the same frequencies on tens of thousands of base stations with only 100MHz of separation with no problems. The same goes for C-band globally with several countries allowing higher power output and smaller guard bands – again with no issues.

    All the other major FAA-equivalent organizations in Europe, Japan, and elsewhere do not share the FCC’s view because there is zero actual evidence of potential interference.

    If the US were the first to deploy C-Band, unknowns might be a concern that is enough to warrant banning use around airports. But we’re not – the US is one of the last developed countries to deploy C-Band for cellular. The risks of using this frequency for cellular are well understood and have a demonstrated track record of non-interference with airlines.

    1. Yves Smith Post author

      Foreign carriers, including the two major Japanese carriers, do not agree. Having worked in Japan, their compliance with regulations is super strict, while the US is of the “sue me” school. So this may reflect their view of the FCC. Note that the article underscores the point made above, that the wireless operators have actually conceded that there might be a problem in arguing that the airlines should change their altimeters, which would be a hugely complicated and time consuming process and would involved ground equipment not under their control:

      Emirates, Japan Airlines, Air India and All Nippon cancel Boeing 777 flights to some US cities over 5G safety fears despite AT&T and Verizon halting rollout

      Emirates is canceling flights to Boston, Chicago, Dallas Fort Worth, Houston, Miami, Newark, Orlando, San Francisco and Seattle indefinitely
      The airline’s flights to JFK, L.A.X and Dulles International Airport are all still operating
      Japan Airlines has canceled three cargo flights and five passenger flights; All Nippon has canceled 20
      Air India is not operating between Delhi and JFK, Chicago or San Fran, or between Mumbai and Newark
      AT&T and Verizon have agreed not to switch on the 5G towers that the airlines are concerned about
      The telecoms giants are frustrated that the industry hasn’t figured out how to fly safely while the towers are in operation
      5G is up and running in other countries in Europe but it is operating at a lower frequency which doesn’t pose as much of a risk to airlines….

      1. Andy

        The fact is that physics is physics and it doesn’t change at the US border. There is a minimum of 400MHZ of separation between these 5G deployments and altimeter frequencies and the carriers had already agreed to limit transmit power near airports – which is much more than many places that currently use the same frequencies.

        Additionally, the contention that radar altimeters or 5G base stations would leak across 400MHz of spectrum is without any evidence. You noted that ” the wireless operators have actually conceded that there might be a problem in arguing that the airlines should change their altimeters” but that isn’t correct. Wireless operators are simply pointing out that it’s the aviation industry’s responsibility to show if there is a problem with the equipment they control and regulate, and that is something the aviation industry hasn’t done. This change has been coming down the pike for years – the FAA and aviation industry have provided no data showing that any of its altimeters will leak across 100MHz of spectrum much less 220 or 400.

        And note that the FAA and aviation industry isn’t asking to make the guard band larger, or suggesting specific mitigation efforts, their position is the C-band is inherently unsafe until proven otherwise and they are deliberately playing on the fears of an ignorant public to try to get their way.

        The justification for this is based on a single industry (AVSI/RTCA) study which did not come to any firm conclusions, and which no one could replicate because the industry refused to release critical data required to validate the study. The aviation industry has had years of time to study if there is a problem and determine if any specific altimeters systems are crappy enough to be vulnerable despite the current mitigation efforts (lower power and a large guard band). They’ve yet to identify a single vulnerable system.

        Meanwhile, regulators in 40+ countries have approved C-band use with lower tolerances (as little as 100MHz of guard spectrum), with all the same types of aircraft (and literally the same aircraft) that operate in the US, and with zero reports of any kind of interference.

        So what is unique about the US that makes this a safety issue here but nowhere else? The FAA and aviation industry don’t have an answer to that.

        The linked articles you posted, for example, state that the airlines canceled the flights at Boeing’s request because Boeing cited the potential safety issues. But the problem is that Boeing, for its part, doesn’t (and can’t) explain why a Boeing 777 can fly safely in Japan with a 100MHz guard band (ie. C-band cellular operating at 4.1 GHz) with a much larger and more robust C-Band deployment, yet the exact same Boeing 777 aircraft might fall out of the sky from US C-band operating 300MHz more distant at 3.8 GHz.

        Boeing has provided no data to show that their systems are actually at risk, much less data that would explain why their systems are at risk in the US while not being at risk everywhere else on the globe where C-Band is utilized.

        This is the core issue the airline industry is eliding because they don’t actually have any evidence that US C-band cellular is uniquely dangerous.

        In short, there needs to be more than claims that a safety issue exists, claims need to be backed up with evidence. The aviation industry has had years to identify any problems and hasn’t.

        So in reality, this is not really about safety because physics is physics. It’s about power and money and the inside baseball of US regulatory politics – and those are always the primary issue whenever spectrum is re-farmed in the US.

        1. Yves Smith Post author

          You apparently have not read the regulatory submissions. This is from an early Jan letter from AT&T and Verizon:

          Nonetheless, the FCC encouraged the aviation community to use the nearly two years before C-Band deployment to upgrade any altimeters that might not be properly designed to filter out frequencies far removed from the 4.2-4.4 GHz altimeter band.

          BillS, who is also an expert in this area, differs from you. He states on this very thread above:

          January 18, 2022 at 11:13 am
          If a nearby transmitter is operating near the operating band-edge of the radar altimeter we can get
          1) desensitization of the radar altimeter receiver front end (its low-noise amplifier or frequency-conversion system). preventing its operation, (can sometimes be corrected by ensuring sharp band-edge rejection in altimeter receive filter).
          2) possible spurious adjacent channel emissions from the 5G transmitter can degrade radar altimeter receiver performance (e.g. raising noise floor, false radar returns, etc. Filtering in altimeter cannot correct this.)

          I imagine that airlines have justified concerns for the safety of their planes and passengers with regards to this problem. I say this as someone who periodically designs aerospace instruments in his day job.

          And carriers would not be cancelling flights, when they still have to pay for overhead (gate rights, moving planes around) if they did not think the risk was real.

          You do not seem to understand that the carriers are in zero risk tolerance industry. They can’t afford to take chances. And push comes to shove, they have way more economic power that the wireless operators. The 5G operators got their pet captured regulator to go along and thought they could steamroll the airlines (who DID object during the rulemaking process) but are finding out otherwise.

          1. Andy

            The FCC does not regulate radar altimeters. The FCC and the cellular carriers do not know if the altimeters are vulnerable to frequencies outside the 4.2-4.4 GHz band that is globally set aside for them. The portion you quote from the January letter is simply pointing out the obvious – that the airline industry and FAA – as the people responsible for designing and certifying radar altimeters – ought to make sure that their equipment is operating in the bandwidth that’s been set aside for that purpose. And the airline industry had 2+ years to accomplish it. The question is, did they do that or not?

            You talk about aviation and zero risk tolerance – I understand that quite well. What does it say about that if the aviation industry cannot certify if altimeters are vulnerable or not after 2+ years of preparation?

            What has yet to be explained is why flying in Japan is completely safe according to the aviation industry, but flying in the US is unsafe. Because if aircraft are flying with altimeters that are not guarded against frequencies outside of the 4.2-4.4 GHz range they are supposed to operate in, then that problem isn’t magically limited to US airspace.

            As noted several times now, the current US deployments have 400MHz of separation from the altimeter bands – that is twice the size of the entire altimeter band. While in Japan there is currently only 100MHz of separation – half the size of the altimeter band. Let’s assume radar altimeters are, in fact, poorly designed and are vulnerable to interference outside of the 4.2-4.4GHz band (which is something the aviation industry has not claimed) – if that’s is the case, then explain the technical reason why flying in Japan is safe while flying in the US is not.

            BillS does not address that in his comment. And furthermore, if what he says is true, then altimeters have been vulnerable and unsafe for a long time. Altimeters get a global, dedicated, and guarded 200MHz of spectrum for a reason and an aviation industry that was actually concerned about zero risk tolerance would ensure that altimeters are not vulnerable to other frequencies.

            The telecom industry very well understands the importance of precision when it comes to frequencies. For cellular equipment in particular, the precision is less than 1MHz. You and I can be standing next to each other with our cell phones connected to the same tower and my phone could be using a 5MHz piece of spectrum and yours could be using a directly adjacent 5MHz piece of spectrum and there would be no interference.

            If altimeters are so imprecise and poorly made that 400MHz of separation is dangerous, then that is, indeed, a huge issue. And if that is, indeed, the case (I don’t think it is), then we ought to stop C-Band near airports in Japan and globally until the aviation industry deploys altimeters that operate in their designated spectrum.

            So again, the disconnect here that has yet to be addressed is that the aviation industry is claiming a safety hazard in the US but is also claiming there isn’t a safety hazard in Japan and other places that use the same equipment using the same cellular standards on the same frequencies and frequencies that are much closer to the altimeter frequencies.

        2. Chris in OK

          When these radar altimeters were designed and built, the frequencies that are being repurposed for 5G were used by C Band satellite – some may remember those old HUGE satellite dishes that people and businesses would have. The earth stations were high power but the signal was highly directional. On the space side the signal was diffuse but by the time it reached the earth the power was quite low. As we have seen over the decades, this setup has been safe.

          Now the FCC allowing telcos to reuse these frequencies for high power ground-based stations using omni directional antennas. This is a change in the environment for these systems and it’s not as simple as adding a filter here or a filter there. Filters decrease the signal and radar altimeters are not high power to start with.

          I realize that we are allergic to such things in America these days, but how about a compromise? The telcos have a ton of spectrum outside of C Band. Why not use other spectrum near airports and C band everywhere else? Radar altimeters are only used on final approach so we are only talking 5 miles or so around an airport. This is a tiny amount of territory in the grand scheme of things.

          Can’t we all just get along?

  14. rowlf

    The National Business Aviation Association has a good FAQ on the 5G problems for helicopters and corporate jets.

    Affected systems:

    Such limitations will severely curtail many aviation operations in low-visibility conditions, and may impact a variety of aircraft systems that integrate radar altimeter data, including:

    Autoland capabilities
    Terrain Avoidance and Warning Systems (TAWS)
    Enhanced Ground Proximity Warning Systems (EGPWS)
    Head Up Displays (HUD)
    Enhanced Flight Vision Systems (EFVS)
    Landing gear “weight on wheels” switches, tied to:
    – Aircraft pressurization
    – Thrust reversers
    – Ground spoilers/lift-dump systems
    – Anti-skid braking

    5G Deployment Frequently Asked Questions

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