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ARINC Southern California SELCAL HF help

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Oct 14, 2006
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#1
I am trying to find what frequency is used by ARINC for aircraft in HF for the SOCAL San Diego area can anyone help?
 
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#5
I'm confused. Selcal or SOCAL, ARINC or MWARA, LDOC or ATC?

ARINC provide a service around the mainland US where aircraft can contact their operations base via an HF radio link and then a phone call to their company operations base - nothing to do with Air Traffic Control at all. MWARA is the "Major World Air Route Area " system where ATC control en route aircraft by HF radio and hand them over to other controllers when they reach the boundary. Selcal is a system where the ATC controller can alert the aircraft flight crew that he want to talk to them without having their HF radio hissing in their ears all the time. ARINC is a company owned by Collins who provide the equipment and operators for ARINC but MWARA controllers are employed by the FAA I believe. There is no LDOC in New Zealand, the major international companies have direct HF communications into their operations offices via discrete frequencies..

Here's a nice big chart that tells you everything..... it's a wee bit out of date but not much has changed....

http://www.liveatc.net/downloads/hfaero.jpg
 
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#8
San Diego County I assume is a land area - they won't be using HF radio at all - VHF radio only in the recognised band and frequencies for that area and altitude. If the aircraft is going out over the ocean then the VHF controller will tell the aircraft to call the MWARA controller at San Francisco on such and such an HF frequency at a time, a reporting point or a Lat/Long position. Any in-flight emergencies will be handled on the normal frequencies - there is no 'special' frequency.
 

ka3jjz

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#10
And if there's any kind of an in flight emergency, it's very unlikely that they'll put it out on such a publicly available system such as HF or VHF. I'm pretty sure they have something like a squawk code that is used for this

Mike
 
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#11
Well, I didn't mean that there would be explicit details of the emergency over the air - a squawk code only brings up an advisory that there is a problem to the radar controller and there are suitably worded "disguises" the flight crew may use to describe the problem or plan to ATC. There are various squawks for various problems which may crop up.
 

dlwtrunked

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#13
Well, I didn't mean that there would be explicit details of the emergency over the air - a squawk code only brings up an advisory that there is a problem to the radar controller and there are suitably worded "disguises" the flight crew may use to describe the problem or plan to ATC. There are various squawks for various problems which may crop up.
You probably mean but some may have misinterpreted
"a squawk code *may* be an advisory that there is a problem to the radar controller" (like 7500 for hijacking, or 7700 for radio failure, or7700 for emergency) but often they are used to indicate something mundane the aircraft is doing like VFR or IFR or a particular operation. Regarding another post, they do not hide an emergency by doing that except perhaps from someone in the ****pit not seeing what they did and what it meant. There are no "secret" means for commercial aircraft to currently communicate - only ways that fewer can receive or decode.
 

bryan_herbert

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#14
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#16
Every blue water aircraft that is HF radio equipped is allotted a 4-letter code. This code stays with the airframe, not registration, not flight number, not company. The 4-letter code relates to 4 musical tones, 2 tones then 2 other tones. A decoder box permanently fitted to the aircraft and listening to the HF radio receiver before the squelch or volume circuitry is continuously listening to the HF radio frequency that the flight deck crew have dialled up because they have been told to by the ATC controller. The flight deck crew do not want to hear the continuous chatter and other selcal tones for other aircraft so they turn the audio gain down. If the ATC controller wants to contact this particular aircraft he transmits the 2x2 tones on the HF frequency - the ATC controller know what the tones are because when the aircraft moved into his sector they carried out a selcal check - the tones decoder on the aircraft hears and responds to the correct code by sending chimes the the flight deck speakers/headphones and also lights a couple of lights on the comm panel. The flight deck bloke who is doing the radio at the time turns up his HF audio on the allotted frequency and transmits "Air NZ flight 1234 answering selcal" and hopefully the ATC controller answers back.

I can't make it any more simple than that.
 

alcahuete

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#17
Is it not a tone that only that specific aircraft can hear? I was trying to be basic as possible.
No it's not. Any aircraft can hear the tones and the transmissions if they have their volume turned up. It is not just heard by a specific aircraft. A specific aircraft will get notification when their specific tone set is broadcast, but it's absolutely nothing like PL. @majoco described very well how it works.

And if there's any kind of an in flight emergency, it's very unlikely that they'll put it out on such a publicly available system such as HF or VHF. I'm pretty sure they have something like a squawk code that is used for this

Mike
100% incorrect. It is all broadcast in the clear on publically accessible frequencies. While the 7700 code can be used to indicate an emergency, that is generally not used by aircraft that are under ATC, and the nature of the emergency and other items would need to be communicated anyway. The only time you're really ever going to see 7700 used is for a VFR aircraft not in communication with ATC, to draw attention to the datablock on the scope.
 
Joined
Jul 13, 2007
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Olive Branch, MS
#18
And if there's any kind of an in flight emergency, it's very unlikely that they'll put it out on such a publicly available system such as HF or VHF. I'm pretty sure they have something like a squawk code that is used for this

Mike
If a pilot has an emergency, it will come out on the radio. I've had a few declare on my frequency, mostly for medical reasons, though I have had one that got an indication of a possible mechanical/electrical issue and returned to their point of departure. A controller can also declare an emergency for a pilot if need be.

Pilots do have the ability to indicate an emergency to a controller via CPDLC as well.
 
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#19
I don't see the point in sending a message via CPDLC when you already in contact with ATC if you are over land and using VHF with the need of a bit of urgency. Even RDARA is quicker than CPDLC although if you using RDARA then it's likely that it's a fair way to your next airport although you could divert to a nearer place that's capable of handling your emergency. Certainly if there's a suitable squawk code for the problem then by all means dial it up as it flashes on the radar controllers screen but if your are out of radar coverage in the boonies or over the ocean what's the point? Quickest is the pilot calling his HF control station and get some advice - it may be medical, it may be engineering but you'll get the quickest answer. I don't think many HF controllers have the luxury of FlightAware or Flightradar24 on their consoles yet and if the aircraft is far away from the nearest receiver there's nothing to see. There's another demon in the cupboard yet - mandatory ADSB by January 2020 in the US - but I don't see any straight answers about flying VFR rules.
 
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