Frequencies and Combined Sectors question...

[ATCWanAaB]

When 2 sectors are combined, do they use 1 frequency? Or does the controller monitor/control on 2 separate frequencies? I have read blog posts by controllers who complain that they have "2 airplanes calling up at the same time on the 2 separate frequencies." But I also know from other posts and visiting facilities that they often use just one frequency for combined sectors.

Any clarification would be appreciated.

[tyketto]

When 2 sectors are combined, do they use 1 frequency? Or does the controller monitor/control on 2 separate frequencies? I have read blog posts by controllers who complain that they have "2 airplanes calling up at the same time on the 2 separate frequencies." But I also know from other posts and visiting facilities that they often use just one frequency for combined sectors.

Any clarification would be appreciated.

I'd rather have someone working at a TRACON answer this, as they will have it absolutely correct, but from my observations, here's how it goes.

When I'm at KLAS, and they combine all their Approach/Departure frequencies (that's about 5 approach and 4 departure) on 125.02 (or where ever they want them all combined), they still transmit on the other frequencies. so I could tune to one of their other frequencies (say, 125.9), and still hear the controller, but not the pilots. So yes, it is possible that 2 separate pilots can call the controller at the same time on two separate frequencies.

Prime example. 125.02 is combined for all of Las Vegas, yet in KVGT's ATIS they specify to call Las Vegas Approach on 133.95 if in the air, or 124.0 on the ground. When that happens, they generally ask the pilot to "change to my frequency 125.02." (see FAA JO 7110.65, 2-1-17.d)

Again, someone here who works at a TRACON can explain what they do better, but this is the jist of it.

BL.

[pilot221]

At my facility (Tower and Tracon) when we combine the tower up, we broadcast it on the atis that everything is combined on the tower frequency. With that, we only transmit on the one frequency. We monitor the other frequencies (clearance/ground) but do not transmit on them. If someone calls up on it, it comes out on the speaker as opposed to the headset so we can decipher what is being said. If we are busy with airplanes in the air, we ignore the other frequencies until they realize what is going on or listen to the full atis (ya you!). If we were to transmit on all frequencies, people get confused and we don't want to hear two people talking at the same time through one ear. If we have time, we will key up on the frequency they were on and tell them to change. It's much easier working everyone on one frequency since everyone can generally hear everyone else so you don't get people stepping on each other and not even know it. On that note, it's preference too. Some like to transmit on all and only listen to them through the speaker and the main one through the headset. Some don't care.

In the tracon, it's slightly different. When it's combined, we listen to all frequencies and transmit on all frequencies. Much bigger airspace and we have different frequencies for each sector depending on where the aircraft is. In one sector you might have 2 frequencies (North/South etc). Also, pilots don't know if it's combined or not...they use the frequencies for their area regardless. We can also monitor other frequencies through the speaker as well which makes it easier to hear both if they are calling at once.

Hope that helped.

[drfinal]

At N90 I like to monitor/ transmit on all freqs for the combined airspace I'm working but I tell everyone I'm on the main freq (125.7) Then have just the main one tuned to my ear and the rest on speaker. If someone forgets and switches someone to the wrong freq it'll come out in speaker and I switch him to "my freq 125.7". Likewise a VFR popup calls on one of the other freqs--I hear it in speaker give him a code and tell him to call 125.7.

Sometimes I just have the other freqs in speaker and I'm not transmitting on them and I'll just change the setting when I need to to transmit...

[RV1]

At my facility, the transmitter coverage can be hampered by the altitude of the aircraft, so we have remote transceivers located at our satellite airports. If a plane comes over at a low altitude but will be transitioning my airspace, I'll be able to talk to him for a certain distance on one freq, then switch him to the next, and so on. This also allows an pilot, sitting on the ground at a satellite airport, to be able to talk to me and get his IFR clearance.
End result: broadcasting and listening on six freqs at a time.

[ATCWanAaB]

Thanks guys. Appreciate the info. Nobody from Enroute chimed in, but ill assume its the same, ie. using the speakers to monitor the other frequencies. 

[MIAMIATC]

I know from listening to alot of ARTCC's on various radios/feeds that late ate night or slow periods they will combine. Here in Florida between JAX/MIA Center late at night there may be as little as 6 High Alt. and 6 Low ALt. sectors working betwen both combined. Slow peiods. Miami Tracon works down with 2 after late hours instead of 10-12 controllers.

[davolijj]

In the centers we'll usually transmit and receive on all the individual sector frequencies for low-altitude combined operations.  Because the airspace is so large, and in many cases the aircraft are so low, we need to use each transmitter site to be able to hear them and for them to hear us.  Many of our low sectors have several different transmitter sites for the same frequency which we toggle depending on the position of the aircraft we're transmitting to.  The VSCS then uses a tool called diversity algorythm to monitor all the available receivers and send the best transmissions to our headset.

For high-altitude we'll use just one frequency and monitor the rest on loudspeaker.

[KSYR-pjr]

The VSCS then uses a tool called diversity algorythm to monitor all the available receivers and send the best transmissions to our headset.

That's a pretty slick application of technology.

[w0x0f]

Leave it to JD to be up on all that techno-geek stuff. 

W0x0f

[davolijj]

 

[ATCWanAaB]

Thanks again. What center you at?

[Canadian eh]

i good rule of thumb is that for every 10NM from the freq source, you need to be 1000' to hear/be heard.
so if your 90NM from the source you gotta be at 9000' to be in radio coverage. this is only a guideline that works pretty well up to about 150-160 NM. freq coverage is usually better than the 10NM-1000' the closer you are to the source.  en route  control is normally broadcast on mult freq. (depending on sector size) for the simple fact that in bigger sectors not every plane is within the freq range of just one freq. hope that helps

[davolijj]

Thanks again. What center you at?

You're welcome, and Memphis.