So, I know that the 777/787 aren't cleared yet but is the 717 cleared yet? Also in general the DC-9 series and other planes like that.

foxecho wrote:

Typical US Government one agency not talking to the other FCC auctioned off those bands a while ago and made billions, FAA never said a thing to them back then.

my two cents
Andrew

FAA and industry explicitly refused cooperating in evaluation of the problem citing proprietary nature of data and equipment.

casinterest wrote:

USAirKid wrote:

casinterest wrote:

CBand for the Wireless companies is 3.7GHz to ~4Ghz
The radar altimeters on the planes are at 4.2 to 4.4 Ghz.

Don't these altimeters understand when the frequency coming back to them is not the one they are sending out?

Or is the Risk, that they can't control the frequency between the plane and the Ground and interference may occur?


Why not a sensible solution that the Cell companies around an airport use lower band frequencies (3.7-3.8)around the airport? The signal should stay out of the 4.2 to 4.4 range, even with 10-20% tolerance issues.

Its the latter. The altimeters don't filter the return properly so it can pick up frequencies outside the 4.2-4.4 Ghz bandwidth.

The FCC has already put a guard band on the wireless companies of a pretty reasonable space.

On a tech forum I saw a post by an RF engineer who stated that this level of poor RF engineering is laughable in today's standards. (I.e. since 2000.)

Any chance of a embedded digital signature so the altimeter recognizes it's own signal/heartbeat? ///( i know the answer will be ...recent technology would but it seems like we have something that people have known was coming for years and was approved in 2020. Did the FAA not lobby hard enough, or did they not foresee the full issue?

Looks like one of altimeters affected, ALA-52, runs on a DSP and 486 processor. A bit too ancient for true GHz operations.

kalvado wrote:

casinterest wrote:

USAirKid wrote:

Its the latter. The altimeters don't filter the return properly so it can pick up frequencies outside the 4.2-4.4 Ghz bandwidth.

The FCC has already put a guard band on the wireless companies of a pretty reasonable space.

On a tech forum I saw a post by an RF engineer who stated that this level of poor RF engineering is laughable in today's standards. (I.e. since 2000.)

Any chance of a embedded digital signature so the altimeter recognizes it's own signal/heartbeat? ///( i know the answer will be ...recent technology would but it seems like we have something that people have known was coming for years and was approved in 2020. Did the FAA not lobby hard enough, or did they not foresee the full issue?

Looks like one of altimeters affected, ALA-52, runs on a DSP and 486 processor. A bit too ancient for true GHz operations.

Yeah, I used a 486 in the 90's in college. I know what it cannot accomplish. But the radar of course only gets control signaling through there.

Derico wrote:

Sorry if this has been asked, but how come in countries where 5G is already rolled out one hasn't heard of any issues? In fact I was in Korea last year for half the year and I don't remember hearing of such a storm around 5G and aviation.

The same problem exists in other countries. The difference is in other countries their governments have acted to restrict 5G near airports while here this issue has been mostly ignored, until now.
Besides operating at a different frequency, they also operate at lower power near airports.
https://www.reuters.com/business/aerosp ... 022-01-18/
"FAA officials have noted the spectrum used by France (3.6-3.8 GHz) sits further away from the spectrum (4.2-4.4 GHz) used for altimeters in the United States and France's power level for 5G is much lower than what is authorized in the United States."
"In South Korea, the 5G mobile communication frequency is 3.42-3.7 GHz band"

https://www.france24.com/en/live-news/2 ... -regulator
"The strength of signals from 5G base stations placed near France's main airports has been restricted,"

Classic case of different government agencies not talking to eachother.

British Airways also modifying its U.S. schedule.

So far canceled for Wednesday;
BA117 LHR-JFK
BA173 LHR-JFK
BA281 LHR-LAX
BA285 LHR-SFO
BA295 LHR-ORD

And aircraft swaps:
BA115 LHR-JFK 777>787
BA175 LHR-JFK 777>A350
BA269 LHR-LAX 777>A380

I just read that the deployment around some key airports has been delayed and ATT & Verizon have agreed to do this. The article does not contain timeframes.

https://www.reuters.com/business/aerosp ... 022-01-18/

hivue wrote:

Revelation wrote:

The issue is the receiver that is a part of the airplane's radar altimeter (RADALT) does not reject the new 5G signals.

Or... the transmitter that is part of the telecomms' new 5G does not adequately control it's signals. Take your pick.

I think this is not the case, the 5G transmitter is transmitting in licensed bands at licensed power levels.

casinterest wrote:

Don't these altimeters understand when the frequency coming back to them is not the one they are sending out?

They do not.

casinterest wrote:

Why not a sensible solution that the Cell companies around an airport use lower band frequencies (3.7-3.8)around the airport? The signal should stay out of the 4.2 to 4.4 range, even with 10-20% tolerance issues.

Presumably those other frequencies already have other uses. As mentioned, there already are "guard bands" that help isolate the 5G and RADALT bands but the RADALT receivers still pick up the out-of-band signals.

USAirKid wrote:

On a tech forum I saw a post by an RF engineer who stated that this level of poor RF engineering is laughable in today's standards. (I.e. since 2000.)

The world was a different place before the 00s. It would have been inconceivable that there would be this much use of frequencies in the 4GHz range back then. It would have seemed absurd to put in extra circuitry to deal with a problem that didn't exist at the time and no one was predicting.

Obviously, the RA equipment needs to be re-certified that it can operate in this new environment. The 5G equipment works fine in its allotted band, and there is plenty of buffer space for which any reasonably designed RA can function. RA equipment simply must be able to filter out near band interference that really isn't that close by in the first place. Yes, you aren't dealing with very low power satellite transmissions anymore, but this migration wasn't a secret. Its like complaining your analog TV can't pick up a signal anymore.

The prudent thing to do is to delay the rollout for proper validation, and potential replacement. Though, the AT&T, Verizon, and anyone else should be compensated for this delay at the behest of the aviation industry which failed miserably here. How can one cry safety at this late stage of the game when all of this was in the works for years? Ignoring a potential problem until the last minute is the antithesis of that. Its just gross incompetence.

Revelation wrote:

hivue wrote:

Revelation wrote:

The issue is the receiver that is a part of the airplane's radar altimeter (RADALT) does not reject the new 5G signals.

Or... the transmitter that is part of the telecomms' new 5G does not adequately control it's signals. Take your pick.

I think this is not the case, the 5G transmitter is transmitting in licensed bands at licensed power levels.

casinterest wrote:

Don't these altimeters understand when the frequency coming back to them is not the one they are sending out?

They do not.

casinterest wrote:

Why not a sensible solution that the Cell companies around an airport use lower band frequencies (3.7-3.8)around the airport? The signal should stay out of the 4.2 to 4.4 range, even with 10-20% tolerance issues.

Presumably those other frequencies already have other uses. As mentioned, there already are "guard bands" that help isolate the 5G and RADALT bands but the RADALT receivers still pick up the out-of-band signals.

USAirKid wrote:

On a tech forum I saw a post by an RF engineer who stated that this level of poor RF engineering is laughable in today's standards. (I.e. since 2000.)

The world was a different place before the 00s. It would have been inconceivable that there would be this much use of frequencies in the 4GHz range back then. It would have seemed absurd to put in extra circuitry to deal with a problem that didn't exist at the time and no one was predicting.

The problem isn’t that it wasn’t designed that way. The problem is that they didn’t take the years since the spectrum was auctioned to either fix it. Or make a comprehensive case to government about why this was a problem. It’s crazy to blame att or Verizon now that they’ve spent billions installing this stuff

One really wonders what the FAA has been doing since 2017 when the 3GHz spectrum was first announced to be available.

Where were the conversation and subsequent regulatory requirements on manufacturers and operators to ensure their avionics were compatible and would operate without interference?

Instead now at the 11th hour, we have this massive hysteria.

We can add this situation to the high competency list of FAA accomplishments that include the original 737MAX certification and (eventually) grounding.

chonetsao wrote:

What I worry is that now it is a 2 agencies fighting. Soon this administration decide to establish another force or agency to manage radio frequency to 'solve' the issues and it will become a 3 agencies fight. In the end nothing gets done in years while more government employments (hence higher tax payers' burden) and endless talks and investigations...

But just think of the lobbyists payday!

kalvado wrote:

ikolkyo wrote:

Curious as to what specific brand of radio altimeters are affected

Looks like https://aerospace.honeywell.com/us/en/l ... -altimeter is affected as it is listed for 777 and those seem problematic. I couldn't find if another one is authorized for 777
But that honeywell model is listed for 737, 747, 757, 767, 777-200, 777-200ER, 777-200LR, 777-300, 777-300ER, 777-8, 777-9, 777F, 787-10, 787-8, 787-9
So.. I am not sure.

Even if another is authorized, who pays for it, and how long to deliver? It took forever and a madcap last minute dash just to get ADSB in the regional fleets.

FlyingElvii wrote:

kalvado wrote:

ikolkyo wrote:

Curious as to what specific brand of radio altimeters are affected

Looks like https://aerospace.honeywell.com/us/en/l ... -altimeter is affected as it is listed for 777 and those seem problematic. I couldn't find if another one is authorized for 777
But that honeywell model is listed for 737, 747, 757, 767, 777-200, 777-200ER, 777-200LR, 777-300, 777-300ER, 777-8, 777-9, 777F, 787-10, 787-8, 787-9
So.. I am not sure.

Even if another is authorized, who pays for it, and how long to deliver? It took forever and a madcap last minute dash just to get ADSB in the regional fleets.

Well, looks like it's better to invest in Amtrak. The way things go, aviation sector would soon become a liability, not an asset.

Chemist wrote:

We can add this situation to the high competency list of FAA accomplishments that include the original 737MAX certification and (eventually) grounding.

Blaming the FAA for this is pretty short sighted. The FCC are the ones primarily responsible for this.

foxecho wrote:

Typical US Government one agency not talking to the other FCC auctioned off those bands a while ago and made billions, FAA never said a thing to them back then.

my two cents
Andrew

The FAA asked them to stop the process pending more investigation more than a year ago and they were involved with a task force that sent a study to to the FCC back in 2020 demonstrating aviation impacts, the FCC went ahead with the December 2020 auction. DOD also sounded the alarm well before now. It's just been publicized more as the date has approached and airlines have sent out warnings about impacts.

https://www.popularmechanics.com/techno ... -concerns/

https://www.bloomberg.com/news/articles ... g-spectrum

https://www.rtca.org/wp-content/uploads ... hanges.pdf

WkndWanderer wrote:

foxecho wrote:

Typical US Government one agency not talking to the other FCC auctioned off those bands a while ago and made billions, FAA never said a thing to them back then.

my two cents
Andrew

The FAA asked them to stop the process pending more investigation more than a year ago and they were involved with a task force that sent a study to to the FCC back in 2020 demonstrating aviation impacts, the FCC went ahead with the December 2020 auction. DOD also sounded the alarm well before now. It's just been publicized more as the date has approached and airlines have sent out warnings about impacts.

https://www.popularmechanics.com/techno ... -concerns/

https://www.bloomberg.com/news/articles ... g-spectrum

https://www.rtca.org/wp-content/uploads ... hanges.pdf

Not really. There was no cooperation."we don't want it period" is not taking things very far.
FAA - and avionics suppliers - could, and should, move their butts a year ago. Creating half-assed document without giving access to underlying data is not the way to solve the problem.

WkndWanderer wrote:

foxecho wrote:

Typical US Government one agency not talking to the other FCC auctioned off those bands a while ago and made billions, FAA never said a thing to them back then.

my two cents
Andrew

The FAA asked them to stop the process pending more investigation more than a year ago and they were involved with a task force that sent a study to to the FCC back in 2020 demonstrating aviation impacts, the FCC went ahead with the December 2020 auction. DOD also sounded the alarm well before now. It's just been publicized more as the date has approached and airlines have sent out warnings about impacts.

https://www.popularmechanics.com/techno ... -concerns/

https://www.bloomberg.com/news/articles ... g-spectrum

https://www.rtca.org/wp-content/uploads ... hanges.pdf

It looks like the aviation industry put forth a disingenuous report. From the above Bloomberg report:

“The test criteria that aviation created is more exacting than existing altimeter standards, and some tested altimeters, operating to manufacturer specifications, would not pass even without any external C-Band operations present,” CTIA said in a Nov. 17 filing.

kalvado wrote:

WkndWanderer wrote:

foxecho wrote:

Typical US Government one agency not talking to the other FCC auctioned off those bands a while ago and made billions, FAA never said a thing to them back then.

my two cents
Andrew

The FAA asked them to stop the process pending more investigation more than a year ago and they were involved with a task force that sent a study to to the FCC back in 2020 demonstrating aviation impacts, the FCC went ahead with the December 2020 auction. DOD also sounded the alarm well before now. It's just been publicized more as the date has approached and airlines have sent out warnings about impacts.

https://www.popularmechanics.com/techno ... -concerns/

https://www.bloomberg.com/news/articles ... g-spectrum

https://www.rtca.org/wp-content/uploads ... hanges.pdf

Not really. There was no cooperation."we don't want it period" is not taking things very far.
FAA - and avionics suppliers - could, and should, move their butts a year ago. Creating half-assed document without giving access to underlying data is not the way to solve the problem.

If the industry “moved their butts” a year ago; they’d have this settled in about 2027 instead of 2028. A bit of joke, but not by much. If it requires new RadAlts to be designed, certified in each Part 25 type, this is a 4-8 year hill to climb.

kalvado wrote:

WkndWanderer wrote:

foxecho wrote:

Typical US Government one agency not talking to the other FCC auctioned off those bands a while ago and made billions, FAA never said a thing to them back then.

my two cents
Andrew

The FAA asked them to stop the process pending more investigation more than a year ago and they were involved with a task force that sent a study to to the FCC back in 2020 demonstrating aviation impacts, the FCC went ahead with the December 2020 auction. DOD also sounded the alarm well before now. It's just been publicized more as the date has approached and airlines have sent out warnings about impacts.

https://www.popularmechanics.com/techno ... -concerns/

https://www.bloomberg.com/news/articles ... g-spectrum

https://www.rtca.org/wp-content/uploads ... hanges.pdf

Not really. There was no cooperation."we don't want it period" is not taking things very far.
FAA - and avionics suppliers - could, and should, move their butts a year ago. Creating half-assed document without giving access to underlying data is not the way to solve the problem.

I haven't seen anything where the FAA said they "don't want it period." I have seen where the FAA and Pentagon asked for delays until at least October 2022 for updated MOPS and that workarounds could take years to develop, validate, and approve.

An FCC head who was a former Verizon counsel pushing ahead with their auction schedule in spite of industry groups, the FAA, and the Pentagon sounding the alarm was hardly the way to solve the problem either.

USAirKid wrote:

WkndWanderer wrote:

foxecho wrote:

Typical US Government one agency not talking to the other FCC auctioned off those bands a while ago and made billions, FAA never said a thing to them back then.

my two cents
Andrew

The FAA asked them to stop the process pending more investigation more than a year ago and they were involved with a task force that sent a study to to the FCC back in 2020 demonstrating aviation impacts, the FCC went ahead with the December 2020 auction. DOD also sounded the alarm well before now. It's just been publicized more as the date has approached and airlines have sent out warnings about impacts.

https://www.popularmechanics.com/techno ... -concerns/

https://www.bloomberg.com/news/articles ... g-spectrum

https://www.rtca.org/wp-content/uploads ... hanges.pdf

It looks like the aviation industry put forth a disingenuous report. From the above Bloomberg report:

“The test criteria that aviation created is more exacting than existing altimeter standards, and some tested altimeters, operating to manufacturer specifications, would not pass even without any external C-Band operations present,” CTIA said in a Nov. 17 filing.

The report pretty obviously talks about how it tested a range of different scenarios, including worse case ones. I'm a bit more inclined to give the benefit of the doubt toward an 85 year old non-profit that also includes non-corporate stakeholders than the cell phone industry's lobbying group.

32andBelow wrote:

The problem isn’t that it wasn’t designed that way. The problem is that they didn’t take the years since the spectrum was auctioned to either fix it. Or make a comprehensive case to government about why this was a problem. It’s crazy to blame att or Verizon now that they’ve spent billions installing this stuff

By "they" it seems you mean FAA and the airline industry.

I try not to blame.

As above I think the airline industry wasn't willing to just "fix it", they would be spending $billions of their own money really just to maintain the status quo. They were perfectly fine with letting things roll to the crisis point where now it's not just their problem to fix. If nothing else, now FAA is highly motivated to find a way to help make the problem go away, and presumably there will be some money and some accommodations found. If the airlines decided to just "fix it" they'd be quietly doing all the heavy lifting by themselves with next to no help.

If AT&T and Verizon spent $billions without any understanding that this issue exists, that'd be on them, but in reality they too knew the spam was going to hit the fan and also were OK with brinksmanship. Bottom line is they want/need frequencies for expansion, and waiting for FAA and FCC to push paper back and forth at each other was going to take forever. Letting the spam hit the fan is helping them get a faster path to a solution. It's pretty clear they actually don't need these frequencies a week from now or two weeks from now, it's more like years from now.

IMO the long term solution is the airlines need to fix their RADALTs, and this exercise in brinksmanship is likely going to help them get various forms of assistance in getting that done.

Revelation wrote:

IMO the long term solution is the airlines need to fix their RADALTs, and this exercise in brinksmanship is likely going to help them get various forms of assistance in getting that done.

The more and more I think about it, this should be a faulty product claim from the airplane owners to Boeing, Airbus, Honeywell, and whoever else.

A vast majority of the affected airline equipment was placed into service within the past 20 years. At that time it was foreseeable that wireless communication was going to rise. At the same time it was known that the filters on the radalts were not filtering out frequencies that were not assigned to that use.

The government and the telecoms should not pay for this. The manufacturers should have delivered equipment that met radio transmission standards in 1996, not 1966.

Was there ever any claims of interference from C band Satellite? That was 3.7 to 4.2 which is pretty close to RADALT.

Juan Brown weighs in. AA 777 FO
https://www.youtube.com/watch?v=s8J2j2PJi1o

Edit to add YT link.

USAirKid wrote:

Revelation wrote:

IMO the long term solution is the airlines need to fix their RADALTs, and this exercise in brinksmanship is likely going to help them get various forms of assistance in getting that done.

The more and more I think about it, this should be a faulty product claim from the airplane owners to Boeing, Airbus, Honeywell, and whoever else.

A vast majority of the affected airline equipment was placed into service within the past 20 years. At that time it was foreseeable that wireless communication was going to rise. At the same time it was known that the filters on the radalts were not filtering out frequencies that were not assigned to that use.

The government and the telecoms should not pay for this. The manufacturers should have delivered equipment that met radio transmission standards in 1996, not 1966.

The 777 design started two years before cellular data was even introduced and three years before dial up internet was released in the U.S. and when the thought of high frequency needs to send videos to your pocket TV wasn't even something Star Trek had shown yet. Don't know how you'd make a "faulty product claim" when the product has been working as intended for decades.

Seems like the easy fix from the start would have been to say it won’t be allowed within X miles from an airport. Or at least, it won’t be allowed within X miles until we know what it does.

Somewhere in the bowels of these government agencies I can hear the engineers saying we told you so. No surprise that in our government the lobbyists and political appointees win the day. This is the result.

WkndWanderer wrote:

USAirKid wrote:

Revelation wrote:

IMO the long term solution is the airlines need to fix their RADALTs, and this exercise in brinksmanship is likely going to help them get various forms of assistance in getting that done.

The more and more I think about it, this should be a faulty product claim from the airplane owners to Boeing, Airbus, Honeywell, and whoever else.

A vast majority of the affected airline equipment was placed into service within the past 20 years. At that time it was foreseeable that wireless communication was going to rise. At the same time it was known that the filters on the radalts were not filtering out frequencies that were not assigned to that use.

The government and the telecoms should not pay for this. The manufacturers should have delivered equipment that met radio transmission standards in 1996, not 1966.

The 777 design started two years before cellular data was even introduced and three years before dial up internet was released in the U.S. and when the thought of high frequency needs to send videos to your pocket TV wasn't even something Star Trek had shown yet. Don't know how you'd make a "faulty product claim" when the product has been working as intended for decades.

You should’ve gone with the 737, it’s type certificate is from the 60s.

I’m arguing that it isn’t the design date that matters, it’s the delivery date that does. (Or perhaps the date when the contract for the plane was first signed.)
At some point it was the manufacturers responsibility to understand that their product wasn’t going to work in a predicted operating environment.

GTI096 diverting to ANC

[threeid][/threeid]

N1120A wrote:

Chemist wrote:

We can add this situation to the high competency list of FAA accomplishments that include the original 737MAX certification and (eventually) grounding.

Blaming the FAA for this is pretty short sighted. The FCC are the ones primarily responsible for this.

If someone thinks the FAA are primarily at fault for MAX woes, then it’s not surprising they’d blame the FAA for this as well.

scbriml wrote:

[threeid][/threeid]

N1120A wrote:

Chemist wrote:

We can add this situation to the high competency list of FAA accomplishments that include the original 737MAX certification and (eventually) grounding.

Blaming the FAA for this is pretty short sighted. The FCC are the ones primarily responsible for this.

If someone thinks the FAA are primarily at fault for MAX woes, then it’s not surprising they’d blame the FAA for this as well.

There's plenty of blame to go around for the 737 MAX issues and the FAA is not off the hook even though Boeing is clearly more at fault than the FAA.
Just like the FCC is at fault here too, but that doesn't mean the FAA doesn't bear a bunch of responsibility for this.
Your answer was quite simplistic.

32andBelow wrote:

GTI096 diverting to ANC

Which makes zero sense to be connected to the 5G issue.

casinterest wrote:

CBand for the Wireless companies is 3.7GHz to ~4Ghz
The radar altimeters on the planes are at 4.2 to 4.4 Ghz.

Don't these altimeters understand when the frequency coming back to them is not the one they are sending out?

Or is the Risk, that they can't control the frequency between the plane and the Ground and interference may occur?


Why not a sensible solution that the Cell companies around an airport use lower band frequencies (3.7-3.8)around the airport? The signal should stay out of the 4.2 to 4.4 range, even with 10-20% tolerance issues.

The auction was done in piece, every 20MHz. Like 3.7-2.72GHz is one segment, 3.72-3.74 is another, and all the way to 3.96-3.98, with the last slice of 3.98-4GHz being reserved exactly for the guarding purpose to separate from other bands, and then there are also another 200MHz between these and the Altimeter frequency.
Modern altimeters can distinguish these different frequencies, but some of the older ones cannot.
3.7-3.8GHz is still part of the FAA complain against the entire band, and limiting operation to this would nullifying two-third of the bidded mobile service capacity which operators spent tons of money to acquire, in addition to they might not be the same company who won the auction of higher parts of the band depending on location as different carriers bid different part of the spectrum and there are also some smaller companies who won a few pieces of these frequencies in some limited geographic area according to my understanding. Limiting operation to lower frequency band would mean all the investment and equipment paid by those who bidded in higher band will be completely wasted, for no good reason since even the closest band is still 220MHz away from the altimeter frequency, when those mobile communication each of them only use 20MHz

GalaxyFlyer wrote:

kalvado wrote:

WkndWanderer wrote:

The FAA asked them to stop the process pending more investigation more than a year ago and they were involved with a task force that sent a study to to the FCC back in 2020 demonstrating aviation impacts, the FCC went ahead with the December 2020 auction. DOD also sounded the alarm well before now. It's just been publicized more as the date has approached and airlines have sent out warnings about impacts.

https://www.popularmechanics.com/techno ... -concerns/

https://www.bloomberg.com/news/articles ... g-spectrum

https://www.rtca.org/wp-content/uploads ... hanges.pdf

Not really. There was no cooperation."we don't want it period" is not taking things very far.
FAA - and avionics suppliers - could, and should, move their butts a year ago. Creating half-assed document without giving access to underlying data is not the way to solve the problem.

If the industry “moved their butts” a year ago; they’d have this settled in about 2027 instead of 2028. A bit of joke, but not by much. If it requires new RadAlts to be designed, certified in each Part 25 type, this is a 4-8 year hill to climb.

I thought Boeing was planning on a whole new type in less than 10 years!

On a serious note, though, scope if work is much smaller. They need add-on filters for existing units, and those can be small ones, size of a matchbox or so.
And if telecom industry can be brought on board, it will be about qualified people who are doing RF for a living, not Boeing or Honeywell, working on the project. 12 months would be about right.
At the very least, there would be a solid understand of a problem, and a reasonable position for limitations required to keep things moving (and flying). Much more solid position for talks.

Revelation wrote:

If AT&T and Verizon spent $billions without any understanding that this issue exists, that'd be on them, but in reality they too knew the spam was going to hit the fan and also were OK with brinksmanship. Bottom line is they want/need frequencies for expansion, and waiting for FAA and FCC to push paper back and forth at each other was going to take forever. Letting the spam hit the fan is helping them get a faster path to a solution. It's pretty clear they actually don't need these frequencies a week from now or two weeks from now, it's more like years from now.

IMO the long term solution is the airlines need to fix their RADALTs, and this exercise in brinksmanship is likely going to help them get various forms of assistance in getting that done.

https://docs.fcc.gov/public/attachments ... 2358A1.pdf

Today, we expand on these efforts to close the digital divide and promote U.S. leadership
in the next generation of wireless services, including fifth-generation (5G) wireless and other advanced
spectrum-based services, by reforming the use of the 3.7-4.2 GHz band, also known as the C-Band. By
repacking existing satellite operations into the upper 200 megahertz of the band (and reserving a 20
megahertz guard band), we make a significant amount of spectrum—280 megahertz or more than half of
the band—available for flexible use throughout the contiguous United States, and we do so in a manner
that ensures the continuous and uninterrupted delivery of services currently offered in the band.

In other words,
Satellite were originally using the 3.7-4.2 GHz frequency
FCC packed the satellite operation to 4.0-4.2GHz
Then leave 3.98-4.0 GHz as guard band between satellite and 5G frequency.
Then they auctioned 3.7-3.98 GHz
Airlines, who are using 4.2-4.4 GHz frequency, is not complaining their neighbor, but rather complaining the neighbor of their neighbor, for interferencing their operation
How is that sensible for the FCC or cellular operator to predict it when they already setup the 3.98-4.00 GHz guard/fence frequency band to prevent interference from satellite, aka the frequency band immediately next to them, and is deemed sufficient.

Also, the report also mentioned that,

348. By licensing only up to 3.98 GHz as flexible-use spectrum, we are providing a 220-
megahertz guard band between new services in the lower C-band and radio altimeters and Wireless
Avionics Intra-Communications services operating in the 4.2-4.4 GHz band. This is double the guard
band supported in initial comments by Boeing and ASRC.

So the guard band requested by Boeing was less than half of 220MHz. In other words Boeing have been okay with 5G up to about 4.1 GHz. Why would mobile operators think 3.x GHz frequency will have problem when Boeing say up to 4.1 GHz is okay?

airbazar wrote:

Derico wrote:

Sorry if this has been asked, but how come in countries where 5G is already rolled out one hasn't heard of any issues? In fact I was in Korea last year for half the year and I don't remember hearing of such a storm around 5G and aviation.

The same problem exists in other countries. The difference is in other countries their governments have acted to restrict 5G near airports while here this issue has been mostly ignored, until now.
Besides operating at a different frequency, they also operate at lower power near airports.
https://www.reuters.com/business/aerosp ... 022-01-18/
"FAA officials have noted the spectrum used by France (3.6-3.8 GHz) sits further away from the spectrum (4.2-4.4 GHz) used for altimeters in the United States and France's power level for 5G is much lower than what is authorized in the United States."
"In South Korea, the 5G mobile communication frequency is 3.42-3.7 GHz band"

https://www.france24.com/en/live-news/2 ... -regulator
"The strength of signals from 5G base stations placed near France's main airports has been restricted,"

Classic case of different government agencies not talking to eachother.

I'd be shocked if this isn't just a classic case of regulatory capture of each agency by both industries. FAA is just a proxy for the airlines and the FCC is just a proxy for the telecoms. Neither agency acts independently and in the best overall interest - just in the best interest of their clients.

N1120A wrote:

32andBelow wrote:

GTI096 diverting to ANC

Which makes zero sense to be connected to the 5G issue.

That’s why they diverted. But they just took off again.

A number of Airlines, out of an abundance of prudent precaution have suspended flights to/from certain USA airports due to the conflict of 5G cell phone transmission/receiver equipment on operations of certain of their guidance and information systems. This is being covered in the news media around the world.

The phone companies know and knew that airports and areas around them will be one of the biggest hot spots for 5G service to allow data and streaming video (mainly for entertainment) to be better. A lot of investment was made by the 3 companies that operate the cell phone networks (AT&T, T-Mobile and Verizon) to expand 5G service to their customers as they demand it and all had to so can be competitive vs. each other. They got the frequencies at very high prices at government auctions, they feel they have the legal right to operate in them as a priority, they see themselves in the right and if the airlines can't comply then its the airlines problems, not the cell phone companies.

Government agencies in the USA failed to work with each other to recognize conflicts of certain 5G cell phone service frequency allocations and certain aircraft instrument guidance and information systems. They auctioned the spectrum for use in and around airports more concerned about revenues and appeasing the phone companies ignoring the conflict until too late. In other countries, like the example of France noted in previous posts here, there was good coordination of government agencies with phone companies to minimize the risk.

Airliners need to be able to operate safely and cannot if certain 5G transmission service is in and around airports using existing, well proven and approved equipment. Changing their equipment is expensive to them, one doesn't make fast changes to equipment, often it is one generation behind, also bogged down by government regulations for good reason. We have seen like with the 737 MAX that sometimes changes are too radical, don't work and it would have been better to keep using older, more proven technology.

So, what happens now ? The USA government cannot have a situation where aircraft cannot operate safely at airports in the country as will just cause further problems with the already difficult trade, supply chain and diplomacy issues from the Covid-19 pandemic. The phone companies want to provide 5G service in and around airport properties. Airlines just cannot modify their equipment and operate in the new 5G phone service environments. For now it looks like 5G service in and around airports will have to be suspended indefinitely until mods are done to comply with safe aircraft operations.

The priority should be safe aircraft operations, phone users will have to realize until those mods are done they will not have 5G service in and around airports.

There is a clear explanation of the issues in Leeham today:

"Despite year-long protests from the World’s airlines and the FAA, the FCC (Federal Communications Commission) allows Verizon and ATT to roll out 5G base stations underneath the approach paths of landing aircraft in the US.

In 2020 the RTCA (Radio Technical Commission for Aeronautics) did tests that established the risk of 5G Base stations affecting the critical Radio Altimeters needed for bad weather landings as real.

After FAA issues a 2021 December 23 AD (Airworthiness Directive) about the danger, airlines must now decide what flights must be canceled during bad weather spells on affected airports."

"Since the FCC decision, FAA and the FCC have argued the issue, with FCC and the wireless industry arguing there have been no problems in other countries. For Europe, this is because the frequency separation is three times the US at 600MHz (5G stops at 3.6GHz). FAA and the airline industry argue air safety is not about “it hasn’t been a problem elsewhere “, only extensive verification and tests can decide if it’s safe or not."

https://leehamnews.com/2022/01/18/us-5g ... more-38286

ltbewr wrote:

A number of Airlines, out of an abundance of prudent precaution have suspended flights to/from certain USA airports due to the conflict of 5G cell phone transmission/receiver equipment on operations of certain of their guidance and information systems. This is being covered in the news media around the world.

The phone companies know and knew that airports and areas around them will be one of the biggest hot spots for 5G service to allow data and streaming video (mainly for entertainment) to be better. A lot of investment was made by the 3 companies that operate the cell phone networks (AT&T, T-Mobile and Verizon) to expand 5G service to their customers as they demand it and all had to so can be competitive vs. each other. They got the frequencies at very high prices at government auctions, they feel they have the legal right to operate in them as a priority, they see themselves in the right and if the airlines can't comply then its the airlines problems, not the cell phone companies.

Government agencies in the USA failed to work with each other to recognize conflicts of certain 5G cell phone service frequency allocations and certain aircraft instrument guidance and information systems. They auctioned the spectrum for use in and around airports more concerned about revenues and appeasing the phone companies ignoring the conflict until too late. In other countries, like the example of France noted in previous posts here, there was good coordination of government agencies with phone companies to minimize the risk.

Airliners need to be able to operate safely and cannot if certain 5G transmission service is in and around airports using existing, well proven and approved equipment. Changing their equipment is expensive to them, one doesn't make fast changes to equipment, often it is one generation behind, also bogged down by government regulations for good reason. We have seen like with the 737 MAX that sometimes changes are too radical, don't work and it would have been better to keep using older, more proven technology.

So, what happens now ? The USA government cannot have a situation where aircraft cannot operate safely at airports in the country as will just cause further problems with the already difficult trade, supply chain and diplomacy issues from the Covid-19 pandemic. The phone companies want to provide 5G service in and around airport properties. Airlines just cannot modify their equipment and operate in the new 5G phone service environments. For now it looks like 5G service in and around airports will have to be suspended indefinitely until mods are done to comply with safe aircraft operations.

The priority should be safe aircraft operations, phone users will have to realize until those mods are done they will not have 5G service in and around airports.

From Taiwan CNA's report, it seems like airlines are suspending the flight according to FAA instruction until FAA release the list of altimeter that comply with their requirement, which then they can resume operation after confirming their altimeters are on the safe list.
It is not like 5G is unique in the world, but since it is FAA instruction so airlines flying into the US would need to follow
Question is why FAA is only releasing the list to airlines now.

ltbewr wrote:

A number of Airlines, out of an abundance of prudent precaution have suspended flights to/from certain USA airports due to the conflict of 5G cell phone transmission/receiver equipment on operations of certain of their guidance and information systems. This is being covered in the news media around the world.

The phone companies know and knew that airports and areas around them will be one of the biggest hot spots for 5G service to allow data and streaming video (mainly for entertainment) to be better. A lot of investment was made by the 3 companies that operate the cell phone networks (AT&T, T-Mobile and Verizon) to expand 5G service to their customers as they demand it and all had to so can be competitive vs. each other. They got the frequencies at very high prices at government auctions, they feel they have the legal right to operate in them as a priority, they see themselves in the right and if the airlines can't comply then its the airlines problems, not the cell phone companies.

Government agencies in the USA failed to work with each other to recognize conflicts of certain 5G cell phone service frequency allocations and certain aircraft instrument guidance and information systems. They auctioned the spectrum for use in and around airports more concerned about revenues and appeasing the phone companies ignoring the conflict until too late. In other countries, like the example of France noted in previous posts here, there was good coordination of government agencies with phone companies to minimize the risk.

Airliners need to be able to operate safely and cannot if certain 5G transmission service is in and around airports using existing, well proven and approved equipment. Changing their equipment is expensive to them, one doesn't make fast changes to equipment, often it is one generation behind, also bogged down by government regulations for good reason. We have seen like with the 737 MAX that sometimes changes are too radical, don't work and it would have been better to keep using older, more proven technology.

So, what happens now ? The USA government cannot have a situation where aircraft cannot operate safely at airports in the country as will just cause further problems with the already difficult trade, supply chain and diplomacy issues from the Covid-19 pandemic. The phone companies want to provide 5G service in and around airport properties. Airlines just cannot modify their equipment and operate in the new 5G phone service environments. For now it looks like 5G service in and around airports will have to be suspended indefinitely until mods are done to comply with safe aircraft operations.

The priority should be safe aircraft operations, phone users will have to realize until those mods are done they will not have 5G service in and around airports.

If I was the telcos I’d be looking for damages if they can’t operate their approved spectrum

JerseyFlyer wrote:

There is a clear explanation of the issues in Leeham today:

"Despite year-long protests from the World’s airlines and the FAA, the FCC (Federal Communications Commission) allows Verizon and ATT to roll out 5G base stations underneath the approach paths of landing aircraft in the US.

In 2020 the RTCA (Radio Technical Commission for Aeronautics) did tests that established the risk of 5G Base stations affecting the critical Radio Altimeters needed for bad weather landings as real.

After FAA issues a 2021 December 23 AD (Airworthiness Directive) about the danger, airlines must now decide what flights must be canceled during bad weather spells on affected airports."

"Since the FCC decision, FAA and the FCC have argued the issue, with FCC and the wireless industry arguing there have been no problems in other countries. For Europe, this is because the frequency separation is three times the US at 600MHz (5G stops at 3.6GHz). FAA and the airline industry argue air safety is not about “it hasn’t been a problem elsewhere “, only extensive verification and tests can decide if it’s safe or not."

https://leehamnews.com/2022/01/18/us-5g ... more-38286

As I mentioned a few pages ago, 5G frequency in this part of frequency band goes up to 4.1GHz in Japan and doesn't appears to be causing issues.

JerseyFlyer wrote:

There is a clear explanation of the issues in Leeham today:

"Despite year-long protests from the World’s airlines and the FAA, the FCC (Federal Communications Commission) allows Verizon and ATT to roll out 5G base stations underneath the approach paths of landing aircraft in the US.

In 2020 the RTCA (Radio Technical Commission for Aeronautics) did tests that established the risk of 5G Base stations affecting the critical Radio Altimeters needed for bad weather landings as real.

After FAA issues a 2021 December 23 AD (Airworthiness Directive) about the danger, airlines must now decide what flights must be canceled during bad weather spells on affected airports."

"Since the FCC decision, FAA and the FCC have argued the issue, with FCC and the wireless industry arguing there have been no problems in other countries. For Europe, this is because the frequency separation is three times the US at 600MHz (5G stops at 3.6GHz). FAA and the airline industry argue air safety is not about “it hasn’t been a problem elsewhere “, only extensive verification and tests can decide if it’s safe or not."

https://leehamnews.com/2022/01/18/us-5g ... more-38286

The very root cause problem, though, that existing FAA structure cannot provide support for safe airline ops. FAA is good at inspecting tags and writing fines, not at solving problems or providing technical expertise.

c933103 wrote:

JerseyFlyer wrote:

There is a clear explanation of the issues in Leeham today:

"Despite year-long protests from the World’s airlines and the FAA, the FCC (Federal Communications Commission) allows Verizon and ATT to roll out 5G base stations underneath the approach paths of landing aircraft in the US.

In 2020 the RTCA (Radio Technical Commission for Aeronautics) did tests that established the risk of 5G Base stations affecting the critical Radio Altimeters needed for bad weather landings as real.

After FAA issues a 2021 December 23 AD (Airworthiness Directive) about the danger, airlines must now decide what flights must be canceled during bad weather spells on affected airports."

"Since the FCC decision, FAA and the FCC have argued the issue, with FCC and the wireless industry arguing there have been no problems in other countries. For Europe, this is because the frequency separation is three times the US at 600MHz (5G stops at 3.6GHz). FAA and the airline industry argue air safety is not about “it hasn’t been a problem elsewhere “, only extensive verification and tests can decide if it’s safe or not."

https://leehamnews.com/2022/01/18/us-5g ... more-38286

As I mentioned a few pages ago, 5G frequency in this part of frequency band goes up to 4.1GHz in Japan and doesn't appears to be causing issues.

Sounds like there is something more to the eye, probably a behind the scenes power trussle than an actual technical issue.

c933103 wrote:

JerseyFlyer wrote:

There is a clear explanation of the issues in Leeham today:

"Despite year-long protests from the World’s airlines and the FAA, the FCC (Federal Communications Commission) allows Verizon and ATT to roll out 5G base stations underneath the approach paths of landing aircraft in the US.

In 2020 the RTCA (Radio Technical Commission for Aeronautics) did tests that established the risk of 5G Base stations affecting the critical Radio Altimeters needed for bad weather landings as real.

After FAA issues a 2021 December 23 AD (Airworthiness Directive) about the danger, airlines must now decide what flights must be canceled during bad weather spells on affected airports."

"Since the FCC decision, FAA and the FCC have argued the issue, with FCC and the wireless industry arguing there have been no problems in other countries. For Europe, this is because the frequency separation is three times the US at 600MHz (5G stops at 3.6GHz). FAA and the airline industry argue air safety is not about “it hasn’t been a problem elsewhere “, only extensive verification and tests can decide if it’s safe or not."

https://leehamnews.com/2022/01/18/us-5g ... more-38286

As I mentioned a few pages ago, 5G frequency in this part of frequency band goes up to 4.1GHz in Japan and doesn't appears to be causing issues.

Those frequencies auctioned in 2019 in Japan - also a band above radalt range is auctioned, would be similar problem. However I don't see any confirmation that these bands are actually deployed.
https://www.everythingrf.com/community/ ... m-in-japan

FAA exempted Boston because the airport wasn’t too close to any towers. Yet Emirates pulls its flight. I’m not saying that 5G isn’t a causal factor here, but nor do I think it’s the sole reason EK is doing this.

kalvado wrote:

c933103 wrote:

JerseyFlyer wrote:

There is a clear explanation of the issues in Leeham today:

"Despite year-long protests from the World’s airlines and the FAA, the FCC (Federal Communications Commission) allows Verizon and ATT to roll out 5G base stations underneath the approach paths of landing aircraft in the US.

In 2020 the RTCA (Radio Technical Commission for Aeronautics) did tests that established the risk of 5G Base stations affecting the critical Radio Altimeters needed for bad weather landings as real.

After FAA issues a 2021 December 23 AD (Airworthiness Directive) about the danger, airlines must now decide what flights must be canceled during bad weather spells on affected airports."

"Since the FCC decision, FAA and the FCC have argued the issue, with FCC and the wireless industry arguing there have been no problems in other countries. For Europe, this is because the frequency separation is three times the US at 600MHz (5G stops at 3.6GHz). FAA and the airline industry argue air safety is not about “it hasn’t been a problem elsewhere “, only extensive verification and tests can decide if it’s safe or not."

https://leehamnews.com/2022/01/18/us-5g ... more-38286

As I mentioned a few pages ago, 5G frequency in this part of frequency band goes up to 4.1GHz in Japan and doesn't appears to be causing issues.

Those frequencies auctioned in 2019 in Japan - also a band above radalt range is auctioned, would be similar problem. However I don't see any confirmation that these bands are actually deployed.
https://www.everythingrf.com/community/ ... m-in-japan

http://blogofmobile.com/article/135612
The Japanese carrier with 4.0-4.1GHz frequency band, KDDI, announced the start of commercial service on this particular band on 2021 March.