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Pluto777
Topic Author
Posts: 5
Joined: Sat Feb 04, 2017 10:16 am

SELCAL obsolete ?

Sat Feb 04, 2017 10:30 am

I ve done many jumpseat long-haul flights (A330) the past years, and i could see that SELCAL is still very much used by ATC to call an aircraft over the atlantic.
Someone told me that SELCAL is almost obsolete now and that new delivered airliners are not even equipped anymore with the typical SELCAL decoders...
Is that true ? Is CPDLC completely taking over the long distance communications ? Will SELCAL dissapear shortly or not ?
 
skyhawkmatthew
Posts: 480
Joined: Wed Oct 26, 2005 4:42 pm

Re: SELCAL obsolete ?

Sat Feb 04, 2017 11:14 am

SELCAL will still be around for a fair while. CPDLC does not satisfy 'continuous monitoring' requirements in the same way as SELCAL does - and neither does SATCOM - and so even when operating on CPDLC with perfect SATCOM coverage we still must check-in on HF and have functioning SELCAL to fly oceanic.
 
Pluto777
Topic Author
Posts: 5
Joined: Sat Feb 04, 2017 10:16 am

Re: SELCAL obsolete ?

Sat Feb 04, 2017 12:29 pm

Thx Matthew for info, i am also HAM radio operator , so glad to hear that good old HF still remains for a while... So actually, the HF reportings (and selcal) are still mandatory for every oceanic crossing ? So CPDLC has not yet become the subsitute ?
 
BravoOne
Posts: 4094
Joined: Fri Apr 12, 2013 2:27 pm

Re: SELCAL obsolete ?

Sat Feb 04, 2017 2:54 pm

Pluto777 wrote:
I ve done many jumpseat long-haul flights (A330) the past years, and i could see that SELCAL is still very much used by ATC to call an aircraft over the atlantic.
Someone told me that SELCAL is almost obsolete now and that new delivered airliners are not even equipped anymore with the typical SELCAL decoders...
Is that true ? Is CPDLC completely taking over the long distance communications ? Will SELCAL dissapear shortly or not ?



Simply not true. Who told you that?? PS I would love to have a selcal chime for my cell phone:)
 
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Balerit
Posts: 624
Joined: Sun Aug 23, 2015 9:14 am

Re: SELCAL obsolete ?

Sat Feb 04, 2017 3:03 pm

Wasn't SELCAL only a link to the aircraft's homebase, never heard of ATC having it?
 
BravoOne
Posts: 4094
Joined: Fri Apr 12, 2013 2:27 pm

Re: SELCAL obsolete ?

Sat Feb 04, 2017 4:16 pm

Its a service providers tool. Think of Shanwick or Gander on the North Atlantic. They will use it to contact the aircraft and coordinate the ATC component. Suggest you Google TRACK WISE as its an excellent overview of the NAT in operation.
 
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zeke
Posts: 16358
Joined: Thu Dec 14, 2006 1:42 pm

Re: SELCAL obsolete ?

Sat Feb 04, 2017 5:22 pm

CPDLC is taking over for a lot of ATC to aircraft communications however away from land mass ( or over remote land areas) this relies on satellite links. The satellite links are via geostationary satellites which do not provide global coverage, aircraft on polar tracks rely on HF data link.

When established CPDLC aircraft are still required to have established two way voice communications via VHF or HF. This can be as simple are requesting SELCAL check. Without SELCAL aircraft will need to maintain continuous listening watch on the radio.

SELCAL works on both VHF and HF radios.

A lot of airfraft are no long built with ADF as GPS has taken over for RNAV or RNP approaches.
 
BravoOne
Posts: 4094
Joined: Fri Apr 12, 2013 2:27 pm

Re: SELCAL obsolete ?

Sat Feb 04, 2017 7:25 pm

zeke wrote:
CPDLC is taking over for a lot of ATC to aircraft communications however away from land mass ( or over remote land areas) this relies on satellite links. The satellite links are via geostationary satellites which do not provide global coverage, aircraft on polar tracks rely on HF data link.

When established CPDLC aircraft are still required to have established two way voice communications via VHF or HF. This can be as simple are requesting SELCAL check. Without SELCAL aircraft will need to maintain continuous listening watch on the radio.

SELCAL works on both VHF and HF radios.

A lot of airfraft are no long built with ADF as GPS has taken over for RNAV or RNP approaches.


Zeke,

Actually Iridium is now the preferred satellite for polar ops as it does cover that gap above 82N. Obviously the airlines are not going to dump the ,millions of dollars they have so far invested in Inmarsat overnight, but it will in time, replace the existing Inmarsat systems.

https://www.faa.gov/about/office_org/he ... Update.pdf
 
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zeke
Posts: 16358
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Re: SELCAL obsolete ?

Sat Feb 04, 2017 7:39 pm

I am familiar with the technology and we do a lot of polar flying. The problem for us is the lack of STCs that are available.

Rockwell Collins has iridium modem for airliners, however it requires an STC for each type before we could use them. Most of the STCs I saw were aimed at the 737/757.
 
BravoOne
Posts: 4094
Joined: Fri Apr 12, 2013 2:27 pm

Re: SELCAL obsolete ?

Sat Feb 04, 2017 7:44 pm

True. Collins has made a big move for the BBJ market but other follow ons for the reasons mentioned above. Not aware of any one kind fits all STC so that may be a show stopper for Cathay. What airframes are doing the 82N operations besides the 777?
 
mcdu
Posts: 1704
Joined: Thu Apr 28, 2005 5:23 am

Re: SELCAL obsolete ?

Sun Feb 05, 2017 3:17 pm

Balerit wrote:
Wasn't SELCAL only a link to the aircraft's homebase, never heard of ATC having it?


It is used frequently for example by ATS when crossing remote areas. Over the Atlantic the crews will get SELCAL check to establish communication with the appropriate ATS (GANDER or SHANWICK). This is used in conjunction with CDPLC. Often the flight will receive a SELCAL from the ATS to verify a position report in the event CPDLC does not send a report. CPDLC is not an authorized substitute for coverage in OCA's. CPDLC is a supplement but not a replacement. Can't imagine anyone ordering an aircraft that is used in CLASS II/ETOPS without SELCAL.
 
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Balerit
Posts: 624
Joined: Sun Aug 23, 2015 9:14 am

Re: SELCAL obsolete ?

Sun Feb 05, 2017 4:55 pm

mcdu wrote:
Balerit wrote:
Wasn't SELCAL only a link to the aircraft's homebase, never heard of ATC having it?


It is used frequently for example by ATS when crossing remote areas. Over the Atlantic the crews will get SELCAL check to establish communication with the appropriate ATS (GANDER or SHANWICK). This is used in conjunction with CDPLC. Often the flight will receive a SELCAL from the ATS to verify a position report in the event CPDLC does not send a report. CPDLC is not an authorized substitute for coverage in OCA's. CPDLC is a supplement but not a replacement. Can't imagine anyone ordering an aircraft that is used in CLASS II/ETOPS without SELCAL.


From the late sixties to the nineties and maybe beyond, we at SAA used SELCAL exclusively from the base station located at Flight Ops in SAA Technical . We had our own radios with massive antennae for keeping in contact with our aircraft due to the sanctions on our country and the very long flights we were doing around the bulge and other destinations. ATC was never a part of this.
 
BravoOne
Posts: 4094
Joined: Fri Apr 12, 2013 2:27 pm

Re: SELCAL obsolete ?

Sun Feb 05, 2017 5:48 pm

SELCAL dates back to at least the mid fifties. Use to use it in what was a former KLM L1049H
 
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7BOEING7
Posts: 3039
Joined: Fri Oct 12, 2012 5:28 pm

Re: SELCAL obsolete ?

Sun Feb 05, 2017 7:34 pm

Balerit wrote:
Wasn't SELCAL only a link to the aircraft's homebase, never heard of ATC having it?


All Boeing airplanes that I flew, that delivered from 1979 thru 2011 had SELCAL installed -- either VHF or VHF and HF. The only airline that was different that I remember was KLM(?) which had a CALSEL(?) on their 733/734's (maybe 747's too) allowing a base to aircraft or aircraft to base call(?). Only flew two SAA airplanes, one a 732 in 1981 which might have had a different system (didn't stand out when I flew it or was installed later) and a 738 in 2002 (which was not used by then per your next post).

Any KLM pilots out there?
 
KingOrGod
Posts: 193
Joined: Mon Jan 16, 2017 3:19 pm

Re: SELCAL obsolete ?

Mon Feb 06, 2017 8:18 am

Balerit wrote:
mcdu wrote:
Balerit wrote:
Wasn't SELCAL only a link to the aircraft's homebase, never heard of ATC having it?


It is used frequently for example by ATS when crossing remote areas. Over the Atlantic the crews will get SELCAL check to establish communication with the appropriate ATS (GANDER or SHANWICK). This is used in conjunction with CDPLC. Often the flight will receive a SELCAL from the ATS to verify a position report in the event CPDLC does not send a report. CPDLC is not an authorized substitute for coverage in OCA's. CPDLC is a supplement but not a replacement. Can't imagine anyone ordering an aircraft that is used in CLASS II/ETOPS without SELCAL.


From the late sixties to the nineties and maybe beyond, we at SAA used SELCAL exclusively from the base station located at Flight Ops in SAA Technical . We had our own radios with massive antennae for keeping in contact with our aircraft due to the sanctions on our country and the very long flights we were doing around the bulge and other destinations. ATC was never a part of this.


I worked FAJS Oceanic, and we used (and still use) SELCAL on all our oceanic traffic (including the orange tails). When we struggled to get them on HF for something, we would call Springbok ZUR and they would use their (directional?) antenna to help us out. But we always did a selcal check on 1st contact so they could turn down the HF speaker as that frikken noise could drive one insane.

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