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island_airphoto
13th May 2024, 10:06
HF propagation has been horrible with very high noise levels the last 2 days or so. Has this disrupted ATC at all on the oceanic routes?

ScotWings
13th May 2024, 10:13
Agreed. It was awful last week and we very nearly couldn’t get a clearance.

ahwalk01
13th May 2024, 10:41
Could it be this?

Aurora - 30 Minute Forecast | NOAA / NWS Space Weather Prediction Center (https://www.swpc.noaa.gov/products/aurora-30-minute-forecast#:~:text=The%20aurora%20is%20an%20indicator,that%20i mpact%20electric%20power%20transition.)

DTA
13th May 2024, 12:00
A Coronal Mass Ejection which sounds fun but it has caused a a severe to extreme (G5) solar storm which hit earth from Friday night. Another smaller peak is expected tonight reportedly. It is the biggest storm since 2003.

island_airphoto
13th May 2024, 12:04
A Coronal Mass Ejection which sounds fun but it has caused a a severe to extreme (G5) solar storm which hit earth from Friday night. Another smaller peak is expected tonight reportedly. It is the biggest storm since 2003.
Polar routes at night might be interesting!
Auroras have been seen south of me at 38 north if the sky is clear.

golfbananajam
13th May 2024, 14:09
Out of interest, are the HF frequencies fixed for all time, or do they change regularly (less than daily) based on atmospheric conditions and the results of, for example, chirp sounding?

Prob30Tempo TSRA
13th May 2024, 14:38
Out of interest, are the HF frequencies fixed for all time, or do they change regularly (less than daily) based on atmospheric conditions and the results of, for example, chirp sounding?

there’s different families of them , and you’ll be allocated an appropriate one for time of day

island_airphoto
13th May 2024, 15:55
Out of interest, are the HF frequencies fixed for all time, or do they change regularly (less than daily) based on atmospheric conditions and the results of, for example, chirp sounding?
They are fixed as in not randomly picked on the spot, but they do have lower and higher frequencies to pick from. I have no idea what tools ARINC and the rest of them use to pick one for the day.
https://radio.arinc.net/atlantic/
https://radio.arinc.net/static/data/ARINC%20HF-VHF%20Voice%20Coverage%20Atlantic-Carribean.pdf
They span from 2 to 18 MHz, so they can usually pick a good one. The last couple of days it has been more like horrible to not working at all for me on the boat HF. Someday maybe airplanes will go to ALE - is anyone working on that? Maybe possible now, I am not sure??

ARINC even has a warning here:HIGHER THAN NORMAL SOLAR ACTIVITY. PLEASE SEE NEW FREQS
GIVE OUT THESE HIGH FREQS AS A 2ND SECONDARY

21964 (LDOCF AND SOUTH AMERICA & CARIB)
21925 (NORTH ATLANTIC)

hoistop
13th May 2024, 19:48
I would guess it has to do with Aurora borealis at its extreme. Two nights ago, we saw a nice aurora borealis - am located at 46 deg N (!). Also internet network in my area was down for a few hours, and again today morning. Not sure if it is connected, but this never happened in last years. Funny to see how such atmospheric (natural) event can (probably) put everything down - I am even unable to check my heating system (heat pump) remotely since Saturday night.

ATC Watcher
13th May 2024, 20:08
It is indeed due solar activities, which we call space weather . There are NOTAMs warning of the areas affected . Should have been on your NOTAM package the last days as current activity is exceptional , Mind you it is not only HF, could also disrupt satellites, i.e GPS.

Cornish Jack
14th May 2024, 09:20
Always had these problems with 'sun-spots'. Very peculiar (and variable) 'skip-distances' which (in the 60s) had our R/C model frequency monitor picking up Italian taxi-driver messages !
H/F has always been variable especially at night ...'trogging' down the West Med at night, impossible to contact Gib but 5/5 with Singapore ! :confused:

double_barrel
14th May 2024, 10:43
It is indeed due solar activities, which we call space weather . There are NOTAMs warning of the areas affected . Should have been on your NOTAM package the last days as current activity is exceptional , Mind you it is not only HF, could also disrupt satellites, i.e GPS.

I can confirm that the amateur HF frequencies were totally dead during the recent solar event. I admit that I rather expected some odd and perhaps enhanced HF propagation rather than a total obliteration. But it's a long time since I did all that theory!

island_airphoto
14th May 2024, 13:27
I can confirm that the amateur HF frequencies were totally dead during the recent solar event. I admit that I rather expected some odd and perhaps enhanced HF propagation rather than a total obliteration. But it's a long time since I did all that theory!
S9 noise mostly, but 6 meters and 2 meters (54 and 144 MHz) could get some aural propagation by aiming due north. Not really enough for voice comms, but you could get some digital modes to make contact.
At the worst of it I could barely get WWV on 10 MHz and not much else.

JRBarrett
14th May 2024, 14:07
It is indeed due solar activities, which we call space weather . There are NOTAMs warning of the areas affected . Should have been on your NOTAM package the last days as current activity is exceptional , Mind you it is not only HF, could also disrupt satellites, i.e GPS.

On Friday afternoon, two of our aircraft (corporate) experienced an FMS advisory “SBAS UNAVAILABLE” at two different geographic locations. This was an indication that the GPS was not receiving an adequate WAAS signal. This was right about the time that the geomagnetic storm was rapidly increasing in intensity. There was an FDC NOTAM issued at 19:45Z that warned that WAAS/LPV might be unavailable for the next 24 to 36 hours. Primary GPS continued working.

J.O.
16th May 2024, 14:55
On Friday afternoon, two of our aircraft (corporate) experienced an FMS advisory “SBAS UNAVAILABLE” at two different geographic locations. This was an indication that the GPS was not receiving an adequate WAAS signal. This was right about the time that the geomagnetic storm was rapidly increasing in intensity. There was an FDC NOTAM issued at 19:45Z that warned that WAAS/LPV might be unavailable for the next 24 to 36 hours. Primary GPS continued working.

Interesting. A colleague of mine who was flying in VMC in a Garmin 500-equipped aircraft last Friday experienced intermittent HDG FAIL messages on both PFDs as well as AHRS ALIGN and ATTITUDE FAIL messages. He was able to clear them by switching AHRS inputs but then they'd come back. During descent, his RAD ALT was scrolling between +2000 ft and 15 ft. Our avionics guru put all of it down to the solar storm interference in the AHRS. It would be pretty disconcerting to have that occur in IMC, especially when your standby instrument has its own AHRS.

Private jet
16th May 2024, 17:53
iirc the useful "night time" frequencies are approx half of the "daytime" frequencies. "Sun up, frequency up. Sun down, frequency down", but with solar storms who knows, cope with the inevitable.

lucille
17th May 2024, 10:17
In this day and age, who doesn’t have satcom on board? You can always “phone home”…. I.e. the call mummy, whom ever ATC you’re supposed to be chatting with.

island_airphoto
17th May 2024, 12:43
If anyone is interested in this stuff, look here for a quick summary of solar weather:
https://solar.w5mmw.net/

DTA
18th May 2024, 12:38
For anyone that may be impacted by this, the sun rotates on a 27 day cycle. It is expected that the sun spot cluster that caused problems last week will still be active when they point back at us in a couple of weeks. The sun is almost at solar maximum when it is most active which is an 11 year cycle.

island_airphoto
18th May 2024, 19:02
if you want to see how bad it can possibly be:
https://en.wikipedia.org/wiki/Carrington_Event

Klauss
20th May 2024, 05:17
Hi, were the ICAO space wether advisories useful ? They are official info, available like here:
https://www.ilmailusaa.fi/warnings.html#top=0#id=swx#FMILang=en#select-area=4
or here:
https://swx-map-service-test.herokuapp.com/
or here:
https://www.swpc.noaa.gov/products/icao-space-weather-advisories
?

markredgwell
24th May 2024, 12:28
More Solar Storms are coming as the Big Sunspot that caused all the Solar Flares is about to rotate back around to face the Earth by he weekend. info on Space weather live.

Per Ardua Ad Asda
29th May 2024, 16:38
www.spaceweather.com is a good source for advance notification of aurorae. You'll only get about 8.25 minutes warning of a potential radio blackout though, as that's how long it takes the X-Ray emissions to reach Earth (i.e. those won't be posted on that site until after they've hit!).