FAA ADs re 5G interference
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FAA ADs re 5G interference
International Federation of Air Line Pilots' Ass'ns (IFALPA) has issued Safety Bulletin: "Aircraft Operations and Radar Altimeter Interference from 5G" (21SAB16). It is based on the Safety Alert issued by ALPA-International under the same name, and contains links to access the FAA Airworthiness Directives.
21sab16-aircraft-operations-and-radar-altimeter-interference-from-5g.pdf (ifalpa.org)
21sab16-aircraft-operations-and-radar-altimeter-interference-from-5g.pdf (ifalpa.org)
International Federation of Air Line Pilots' Ass'ns (IFALPA) has issued Safety Bulletin: "Aircraft Operations and Radar Altimeter Interference from 5G" (21SAB16). It is based on the Safety Alert issued by ALPA-International under the same name, and contains links to access the FAA Airworthiness Directives.
21sab16-aircraft-operations-and-radar-altimeter-interference-from-5g.pdf (ifalpa.org)
21sab16-aircraft-operations-and-radar-altimeter-interference-from-5g.pdf (ifalpa.org)
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Er, $67.06c per airframe? Sum mistake Shirley?
FAA cost estimates in AD's tend to be pretty optimistic. Plus, the costs are only listed for US based aircraft.
https://www.federalregister.gov/docu...us-helicopters
https://www.federalregister.gov/docu...gory-airplanes
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Just to be clear - the cost to operators some have mentioned above reflects the cost to update the paper or electronic AFM with a new page containing the new Limitation. It does not reflect the costs of the cancelled flights or diversions or Missed Approaches and Go Arounds or the costs of the new equipment (Radar Altimeters and Software) we'll all need to purchase down the road. That's going to be closer to a $1 million per a/c I expect before more adaptable Rad Alts can be developed and installed.
Last edited by nnc0; 11th Dec 2021 at 11:42.
WillowRun 6-3,
Apart from marking a major blow-up between US Federal government agencies and thereby providing a potentially entertaining “pass the popcorn” opportunity for those of us outside the USA, does this escalation in inter-agency hostilities have any collateral benefits for US airlines?
For example, can an airline now sue the FCC because it will be able to demonstrate an actual loss (e.g. “We can no longer schedule flights to XXX after dark or in bad weather”) whereas before they could only point out a potential detriment?
Apart from marking a major blow-up between US Federal government agencies and thereby providing a potentially entertaining “pass the popcorn” opportunity for those of us outside the USA, does this escalation in inter-agency hostilities have any collateral benefits for US airlines?
For example, can an airline now sue the FCC because it will be able to demonstrate an actual loss (e.g. “We can no longer schedule flights to XXX after dark or in bad weather”) whereas before they could only point out a potential detriment?
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WillowRun 6-3,
Apart from marking a major blow-up between US Federal government agencies and thereby providing a potentially entertaining “pass the popcorn” opportunity for those of us outside the USA, does this escalation in inter-agency hostilities have any collateral benefits for US airlines?
For example, can an airline now sue the FCC because it will be able to demonstrate an actual loss (e.g. “We can no longer schedule flights to XXX after dark or in bad weather”) whereas before they could only point out a potential detriment?
Apart from marking a major blow-up between US Federal government agencies and thereby providing a potentially entertaining “pass the popcorn” opportunity for those of us outside the USA, does this escalation in inter-agency hostilities have any collateral benefits for US airlines?
For example, can an airline now sue the FCC because it will be able to demonstrate an actual loss (e.g. “We can no longer schedule flights to XXX after dark or in bad weather”) whereas before they could only point out a potential detriment?
For an airline to file a lawsuit against the FCC, among the issues I'd want to hammer down is, to what extent is it realistic to anticipate that a federal district court (presumably where suit would be filed) would even have the competence to deal with the technical issues? While it is true that federal district courts do see litigation involving arcane and complex subject matters, these are subjects which get presented to the courts with some frequency, and do not present new technology just now entering service. (It's not perfect as a comparison, but consider what a hash Congress has made with regard to establishing regulatory frameworks for social media.) And in complex arcane matters before federal courts at present, I think most veteran litigators - and especially their clients - would concur with the assessment that the results of those cases leave a lot to be desired. It's one thing to get the statute of limitations analysis, where equitable tolling arguments are made, correct - quite another to resolve dueling expert witnesses with regard to proper statistical techniques for assessing results of Phase III clinical trial of a prostate cancer pharma product. So I would question whether the court, in perhaps a novel turn of a standard phrase, is a court of competent jurisdiction.
Of course an airline might go ahead and sue as part of a political effort by airlines. Or for some notion of public relations points. On the other hand, what actual claims could be made -- abuse of discretion under the Chevron deference-to-agency interpretation of statutory provisions? - I don't know. I mean, I don't know the answer already, plus I'm not planning on drilling into it (uh, absent an actual client, that is), plus there's more to respond to in your question.
So this is a "blow-up" between federal agencies?, "escalating inter-agency hostilities"? Well, it's really not. Because as you know the FAA is "housed" within the Department of Transportation, which is headed by a political appointee. The current Secretary's background for his appointment and confirmation by the Senate - apart from some slick presidential primary campaigning which of course is utterly meaningless - is that he was Mayor of a small city the apparatus of which is dominated by a major private university (Notre Dame). So in refusing to let cellular providers take control, the FAA has stepped into the breach. And it was able to do so, in major part, precisely because the Department in which FAA is situated is headed by a Secretary who really does not have much knowledge whatsoever about, you know, how things work (and don't work) up front, that so-called pointy end of the airplane. Just my view, not an official or verifiable opinion, of course.
But your post did more, for it reminded your loyal forum SLF/atty of how much I enjoyed popcorn during some several months when I held a volunteer gig (sort of) at Chicago O'Hare. And to return the favor, and since the first real blow-up was, of course, in 1966 and directed by Michelangelo Antonioni and produced by Carlo Ponti - for your enjoyment of a non-U.S.A. film to accompany that popcorn:
Blow-Up (imdb.com)
Anyhow, the drive behind the AD is a simple change to the flight manual IF there is a NOTAM out on the problem.....
My guess is the number of NFF removals of RA's is going to go through the roof, or worse, real problems are going to be signed off as 5G issues. What a mess

Amazing state of affairs.
LRRA are pretty much essential equipment for approaches below CAT I minima. So, yeah, that's a bit of a nuisance. At least the weather in the USA, like JFK, IAD, ORD never goes bad, It's all like California, or Queensland, beautiful one day perfect the next. Same for CDG, LHR, EDDF etc in the EU. Great.
I seem to recall once we were told how GPWS works, a mandated system... so, presumably the GPWS escape manoeuvers that ensue from the erroneous ramp-up of LRRAs will be enjoyed by one and all. Going to be most entertaining in a stack as someone gets a false GPWS "pull up" and bobbles through the pack above.
Will the FAA send out a revision to this lunacy with an edict to disconnect the LRRA input to de-activate GPWS systems? that would be something that would look bad on your resume after the first pax plane plants itself in the sod with a crippled GPWS system. EGPWS is faaaantastic, but GPWS is still mandated by the FARs, but perhaps it now gets partial retirement by EGPWS... except that multiple modes of GPWS are not provided by EGPWS... hmmm. Maybe it is just software, just like the change from 7.0 to 7.1 which was just software at about $100,000 per box, after all it's not like Honeywell to miss a chance to fleece the industry.
At least GPS is a fine basis for all safety systems, except, in the last 18 months around the SCS region, where the dispute over 9 line vs every other nation in the world seems to curiously result in jamming by persons unknown of GPS signals, taking out independent certified GPS systems of different design, OEM, op software. That is a bit untidy for EGPWS systems. Remarkably, there are some systems that are not certified that continue to work reliably and also give EGPWS guidance. Neat that the certified system gets jammed and messed by unknown jammers with disregard for civil aviation, yet the uncertified systems work like a charm.
Glad to see that the FCC and FAA had everyone's backs on this one.
LRRA are pretty much essential equipment for approaches below CAT I minima. So, yeah, that's a bit of a nuisance. At least the weather in the USA, like JFK, IAD, ORD never goes bad, It's all like California, or Queensland, beautiful one day perfect the next. Same for CDG, LHR, EDDF etc in the EU. Great.
I seem to recall once we were told how GPWS works, a mandated system... so, presumably the GPWS escape manoeuvers that ensue from the erroneous ramp-up of LRRAs will be enjoyed by one and all. Going to be most entertaining in a stack as someone gets a false GPWS "pull up" and bobbles through the pack above.
Will the FAA send out a revision to this lunacy with an edict to disconnect the LRRA input to de-activate GPWS systems? that would be something that would look bad on your resume after the first pax plane plants itself in the sod with a crippled GPWS system. EGPWS is faaaantastic, but GPWS is still mandated by the FARs, but perhaps it now gets partial retirement by EGPWS... except that multiple modes of GPWS are not provided by EGPWS... hmmm. Maybe it is just software, just like the change from 7.0 to 7.1 which was just software at about $100,000 per box, after all it's not like Honeywell to miss a chance to fleece the industry.
At least GPS is a fine basis for all safety systems, except, in the last 18 months around the SCS region, where the dispute over 9 line vs every other nation in the world seems to curiously result in jamming by persons unknown of GPS signals, taking out independent certified GPS systems of different design, OEM, op software. That is a bit untidy for EGPWS systems. Remarkably, there are some systems that are not certified that continue to work reliably and also give EGPWS guidance. Neat that the certified system gets jammed and messed by unknown jammers with disregard for civil aviation, yet the uncertified systems work like a charm.
Glad to see that the FCC and FAA had everyone's backs on this one.
Last edited by fdr; 13th Dec 2021 at 02:35.
Suggest all Ops Managers, and all flight crew that have a desire to have GPWS send their seasons greetings to:
Brett Portwood, Continued Operational Safety Technical Advisor, COS Program Management Section, Operational Safety Branch, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 817-222-5390; email: operationalsafety at the good ol' FAA dot GOV.
At this time, the constraints are to remove SA CAT I/II/III, Autoland, EVS and the like at the NOTAMed airports, but your GPWS system is also compromised, so expect warnings to go off. Just what you want is a warning system that goes off randomly, it results in a resistance to response that may affect real warnings. The insanity of this nonsense is breathtaking, the only realistic defence is to have VMC operations only below safety height, which should pretty much stop all turbine traffic in the east of the USA that may be subject to this NOTAM in the season of cheer... or risk repetitive false warnings resulting in resistance to response in real cases, that's what humans do. We are good at learning workarounds, and those workarounds tend to become pavlovian heuristics that have unintended consequences. Of course, Collins, Honeywell and co, can always come up with new LRRAs that operate on a new band, that shouldn't take more than 5 years to push through, and about 25K per aircraft, 3 times that for Boings and Airbusses etc...
Wish that the FAA and FCC had kept with just making a stew to go with yoghurt and tabbouleh instead of becoming amorous with the goats.
FAA 2021-23-12 DOCKET

At least IATA and IFALPA understands the issue, even if it was subsequently disregarded in the FAA AD...
IATA PROBLEM STATEMENT 27 NOV 20 MONTREAL
List of potential equipment failures:
Interference to RA operations can affect:
1. Autoland functions: This is particularly critical in low visibility auto approach like Cat II or III conditions. Pilots cannot conduct CAT II and III approaches if RA is malfunctioning.
2. EICAS/ECAM: Nuisance warning after take-off or during approach which will distract crew from their tasks at hand. This will lead to deterioration of operational safety levels.
3. False or missing GPWS alert: Anywhere in proximity to ground, this could inhibit some functionalities of the TAWS (Terrain Alerting Warning System) reactive modes which would remove a safety net in case against CFIT (Controlled Flight Into Terrain). Additional distractions for crews from tasks at hand, – “too low gear” and “too low flaps”, “don’t sink”,” terrain and pull up warning” and other alerts. A big concern is GPWS not triggering an alert when it should have done so, because of interference which can result in CFIT event!
4. Unreliable instrument Indications: This could contribute to an increased number of hard landings because of errors in automatic altitude indications and voice announcements.
5. Abnormal behaviours in Automatic Flight Systems: a. Autoland system b. Flight Control Laws (e.g. failure to transition to Flare law resulting in a higher than expected pitch on the flare; Retard function, etc.) c. Auto-throttle automatic stall protection. d. Auto Speedbrake deployment
Remember, your busses, big 'n little, use RA for determining control laws.... watch this space...
In spite of the perceptiveness of IATA and IFALPA in NOV 2020, we get 5G on the same band as the RA's???? WTF!
Brett Portwood, Continued Operational Safety Technical Advisor, COS Program Management Section, Operational Safety Branch, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 817-222-5390; email: operationalsafety at the good ol' FAA dot GOV.
At this time, the constraints are to remove SA CAT I/II/III, Autoland, EVS and the like at the NOTAMed airports, but your GPWS system is also compromised, so expect warnings to go off. Just what you want is a warning system that goes off randomly, it results in a resistance to response that may affect real warnings. The insanity of this nonsense is breathtaking, the only realistic defence is to have VMC operations only below safety height, which should pretty much stop all turbine traffic in the east of the USA that may be subject to this NOTAM in the season of cheer... or risk repetitive false warnings resulting in resistance to response in real cases, that's what humans do. We are good at learning workarounds, and those workarounds tend to become pavlovian heuristics that have unintended consequences. Of course, Collins, Honeywell and co, can always come up with new LRRAs that operate on a new band, that shouldn't take more than 5 years to push through, and about 25K per aircraft, 3 times that for Boings and Airbusses etc...
Wish that the FAA and FCC had kept with just making a stew to go with yoghurt and tabbouleh instead of becoming amorous with the goats.
FAA 2021-23-12 DOCKET

At least IATA and IFALPA understands the issue, even if it was subsequently disregarded in the FAA AD...
IATA PROBLEM STATEMENT 27 NOV 20 MONTREAL
List of potential equipment failures:
Interference to RA operations can affect:
1. Autoland functions: This is particularly critical in low visibility auto approach like Cat II or III conditions. Pilots cannot conduct CAT II and III approaches if RA is malfunctioning.
2. EICAS/ECAM: Nuisance warning after take-off or during approach which will distract crew from their tasks at hand. This will lead to deterioration of operational safety levels.
3. False or missing GPWS alert: Anywhere in proximity to ground, this could inhibit some functionalities of the TAWS (Terrain Alerting Warning System) reactive modes which would remove a safety net in case against CFIT (Controlled Flight Into Terrain). Additional distractions for crews from tasks at hand, – “too low gear” and “too low flaps”, “don’t sink”,” terrain and pull up warning” and other alerts. A big concern is GPWS not triggering an alert when it should have done so, because of interference which can result in CFIT event!
4. Unreliable instrument Indications: This could contribute to an increased number of hard landings because of errors in automatic altitude indications and voice announcements.
5. Abnormal behaviours in Automatic Flight Systems: a. Autoland system b. Flight Control Laws (e.g. failure to transition to Flare law resulting in a higher than expected pitch on the flare; Retard function, etc.) c. Auto-throttle automatic stall protection. d. Auto Speedbrake deployment
Remember, your busses, big 'n little, use RA for determining control laws.... watch this space...
In spite of the perceptiveness of IATA and IFALPA in NOV 2020, we get 5G on the same band as the RA's???? WTF!
Last edited by fdr; 13th Dec 2021 at 05:01. Reason: IATA
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testing
Hi, would anyone know what the FAA action is based on ? Did they test actual equipment, i.e. radio altimeters near 5G antennas, or did they study the literature which says there is a possibility that there might be trouble ? I am hoping that tests have been conducted to get to the bottom of this ....
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I'm a PNT technologist not a pilot and only comment (occasionally) on technical matters. I used (a very long time ago) to be an FAA qualified Aircraft dispatcher, There was a US PNT Advisory Board (PNTAB) meeting in Washington last week at which Hon. Jeff Shane, IATA Representative & PNTAB Member gave a presentation on recent FCC decisions and implications. I can't post a link but the presentation is here and quite informative... perhaps someone else could post/share for me. The presentation is available to download on the gps.gov website under the PNT Advisory Board Dec 9-10. , Dec 09 5.15-5.40pm.5th Meeting
December 9-10, 2021
December 9-10, 2021
I'm a PNT technologist not a pilot and only comment (occasionally) on technical matters. I used (a very long time ago) to be an FAA qualified Aircraft dispatcher, There was a US PNT Advisory Board (PNTAB) meeting in Washington last week at which Hon. Jeff Shane, IATA Representative & PNTAB Member gave a presentation on recent FCC decisions and implications. I can't post a link but the presentation is here and quite informative... perhaps someone else could post/share for me. The presentation is available to download on the gps.gov website under the PNT Advisory Board Dec 9-10. , Dec 09 5.15-5.40pm.5th Meeting
December 9-10, 2021
December 9-10, 2021
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To add perhaps some significance to one of the above posts, Jeff Shane is General Counsel of IATA - in the realms of public and private international air law, positions for attorneys working as lawyers don't get any more significant than that. (Correction: Mr. Shane retired as GC summer 2020 - but still.)
Here's the link to the agenda for the PNTAB meeting recently, in case it might be of interest.
GPS.gov: 25th Meeting of the National Space-Based Positioning, Navigation, and Timing Advisory Board - December 2021
(Also, in my previous post, I was somewhat tentative in arguing that the FAA had stepped into what it saw as a kind of power vacuum. It appeared that the cellular providers had been able to out-lobby, out-money, and out-influence the voices of and advocates for integrity of the aviation safety ecosystem. And that with the start of this White House administration, its Secretary of Transportation - lacking as he does any operational experience or insight with regard to aviation operations or safety, or big-league interest infighting in Washington (despite his other fine qualities) - had emerged as a . . . . bystander. So rather than cede the playing field to the cellular providers, and knowing that the current DoT leader isn't a heavy-hitter like Liddy Dole or Elaine Chao, FAA took the bull by the horns. I think, with the explanation of just how bad the risks to operational aviation safety really are (THANK you fdr and others), this power-match map looks even more accurately drawn.)
With U.S. Permanent Rep to ICAO Council, Ambassador Chesley "Sully" Sullenberger having now been sworn in to his office, maybe something different can take shape. Hope springs eternal.
Here's the link to the agenda for the PNTAB meeting recently, in case it might be of interest.
GPS.gov: 25th Meeting of the National Space-Based Positioning, Navigation, and Timing Advisory Board - December 2021
(Also, in my previous post, I was somewhat tentative in arguing that the FAA had stepped into what it saw as a kind of power vacuum. It appeared that the cellular providers had been able to out-lobby, out-money, and out-influence the voices of and advocates for integrity of the aviation safety ecosystem. And that with the start of this White House administration, its Secretary of Transportation - lacking as he does any operational experience or insight with regard to aviation operations or safety, or big-league interest infighting in Washington (despite his other fine qualities) - had emerged as a . . . . bystander. So rather than cede the playing field to the cellular providers, and knowing that the current DoT leader isn't a heavy-hitter like Liddy Dole or Elaine Chao, FAA took the bull by the horns. I think, with the explanation of just how bad the risks to operational aviation safety really are (THANK you fdr and others), this power-match map looks even more accurately drawn.)
With U.S. Permanent Rep to ICAO Council, Ambassador Chesley "Sully" Sullenberger having now been sworn in to his office, maybe something different can take shape. Hope springs eternal.
Last edited by WillowRun 6-3; 13th Dec 2021 at 21:35. Reason: Correction noted
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Airbus Vs Rad Alr Vs 5G
A bigger issue ,as far as I can see, is that even in perfect weather any, sustained disturbance in the RA signal on the Airbus could cause a downgrade in the control laws. Definitely not something you want at the bottom of an approach in a windy day.........