OPNLguy From , joined Dec 1969, posts, RR:
Reply 1, posted (12 years 10 months 3 weeks 1 day 19 hours ago) and read 5947 times:
SELCAL stands for SELective CALl.
Monitoring the radio, especially on longer flights, can be a real pain in the ears, and a distraction. SELCAL works in conjunction with a VHF or HF radio aboard the aircraft, freeing the crew from having to monitor the radio.
When a company dispatcher needs to contact an aircraft, they get on the radio and key-in the 4-character alpha code specific to the intended aircraft, and when the aircraft radio receives it, a blue light and chime will alert the crew, and they'll then turn up their radio volume and converse as needed.
EssentialPowr From United States of America, joined Sep 2000, 1820 posts, RR: 2
Reply 2, posted (12 years 10 months 3 weeks 1 day 19 hours ago) and read 5924 times:
SELCAL = SELective CALling
The system continuously monitors a preset freq from a network of ground stations that are specially equipped with an encoding device that enables a specific a/c from a specific airline or company to be called.
In a General description of the system, a regionally specific freq printed in the Jepps must be monitored by the (typically) #2 VHF. An incoming call triggers the Aural unit in the a/c to say "SEL CAL", so the crew can then hit the PTT and talk to dispatch. The system is then reset by activating the PTT button.
Vaporlock From , joined Dec 1969, posts, RR:
Reply 9, posted (12 years 10 months 3 weeks 1 day ago) and read 5804 times:
>Dc10hound, I understand what you mean by "an electronic dog leash" especially if Mother keeps calling from the nest over & over again! It sounds like a high power "pager" system, and I guess a lot of questions would be asked if the pilots didn't respond.
The reason I thought that pilots would have been happy when SELCAL was installed is because of what OPNLguy said.."Monitoring the radio, especially on longer flights, can be a real pain in the ears, and a distraction".
I also understand that this system uses a VHF radio that could be used to contact ATC if needed, however it's normally dedicated to the SELCAL.
OPNLguy From , joined Dec 1969, posts, RR:
Reply 11, posted (12 years 10 months 3 weeks 21 hours ago) and read 5789 times:
It's true that there are some crews out there who consider SELCAL and other similar devices as a nuisance or otherwise an electronic "leash" , but there's another perspective to consider....
Flightcrew members can initiate contact with their dispatch center just about anytime they want, and the dispatch office never moves or changes its phone number. Conversely, if a dispatcher wants (or more importantly, *needs*) to contact his/her flight(s), the dispatcher has to have a predictable uplink path in order to do so. That means the crews need to have their SELCAL units "on" (a few don't), and the associated radio tuned to the proper frequency. This way, if the dispatcher needs to be the one initiating the contact, they'll get through.
Some crews don't fully consider this need, thinking that once they're airborne, they're completely on their own, and don't have any use for anyone on the ground. In some contexts, they're absolutely correct, but in others, they forget that the airline (as an entity) must maintain positive operational control of the airline, including during flight time.
I can't count the times I've initiated contact to pass along updated weather conditions, changes in planned operation(s), and making contact on behalf of ATC (with a missed frequency change), and if that uplink path wasn't there, flight safety might have been compromised. In these post-9/11 times, we also have more potential security issues to deal with. If I can't contact one of our flights that's temporarily not talking with ATC (missed freq change above), they nowdays get scrambled upon. Not exactly great customer relations when passengers see a couple of F15s or F16s forming up with you at FL330...
To sum it up, sorry if our calls are deemed nuisances, but we have our jobs to do as well.
727pfe From , joined Dec 1969, posts, RR:
Reply 12, posted (12 years 10 months 3 weeks 13 hours ago) and read 5766 times:
I disagree with the satement about using selcal with ATC. It's used quite extensively when crossing the pond. You give your selcal code to ATC and they contact you when they want to talk to you. It saves having to listen to HF for an extended period.