Author Topic: Question regarding Montreal Centre frequencies 134.975 and 128.775 (Ottawa area)  (Read 12425 times)

Offline janlam01

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I am hoping somebody with knowledge of Montreal Centre frequencies surrounding Ottawa could help answer these questions:

1) Does anyone know how frequencies 134.975 and 128.775 are “mapped out”?

(I have determined that frequencies 124.275/135.2 cover areas west and northwest of Ottawa until it reaches Toronto Centre, and 126.575 cover areas north of Ottawa)

2) When aircrafts are going to Ottawa following the “RIVER9 STAR”, are they generally on 128.775 prior to being switched to Ottawa Terminal for Arrivals?

Long explanation for those questions
The reason I am asking is because the CYOW feed contains a Montreal Centre frequency 124.275 (though listed as "Ottawa Terminal"). Over the last few months, I noticed/discovered that around after 10pm ET (though the precise start time varies day-to-day) into the overnight hours, many other Montreal Centre frequencies become available into the feed. As such, I had the opportunity to create a couple of "typical flight" audio clips between Ottawa (CYOW) and Montreal (CYUL).

Recently when I was putting together the audio clip for Air Canada Jazz 8779 from Montreal to Ottawa, I heard Montreal Terminal for Departures handing off the flight to Montreal Centre frequency 128.775 instead of 134.975 - this would have been the first time I actually heard a Controller handing off an aircraft to that frequency.

After creating that audio clip for Jazz 8779, I searched on Flightaware whether there were any other (delayed) flights to Ottawa that would follow the RIVER9 arrival that could be heard on the CYOW feed when they are on 128.775 (as Jazz 8779 followed the RIVER9 STAR into Ottawa from Montreal). As it turned out, I did find a couple of late flights that could be heard when it was on that Montreal Centre frequency before switching to Ottawa Terminal - one on Dec 21/22 and another on Dec 22/23 heard in the CYOW feed. In fact when listening to the archive audio of those flights, they actually checked in with Montreal Centre initially on frequency 132.350 before later switching to 128.775 - conversation on both frequencies from those two flights heard on the CYOW feed.

Now, I have seen frequency 128.775 listed on a Nav Canada Enroute high-altitude charts posted on IVAO.ca, where the frequency could be used in the Ottawa area. But never have I heard Ottawa Terminal for Departures handing off an aircraft to that frequency before going to a destination east of Ottawa. With my lack of knowledge of how the Montreal Centre frequencies are precisely mapped out, I have always had the impression that frequency 134.975 is responsible for areas east of Ottawa, south of Ottawa and within the Canadian border, and west of Montreal. After hearing 128.775 being used, I am a bit confused in the area coverage of this frequency versus 134.975.

I have put together an audio clip containing three Porter flights on both Montreal Centre frequencies that is almost 7 minutes long:
- Porter 287 on Dec 21/22 departing Ottawa to Halifax where Ottawa Terminal does a hand off to Montreal Centre on 134.975, then later asked to switch to the Controller's "other frequency" to 132.350, then a handoff to Boston Center on 128.05;
- Porter 272 on Dec 21/22 from Moncton to Ottawa where the pilot initially checked into Montreal Centre on frequency 132.350 from Boston Center 128.05, then later asked to switch to the Controller's "other frequency" on 128.775, then a handoff to Ottawa Terminal followed by Ottawa Tower; and
- Porter 282 on Dec 22/23 from Halifax to Ottawa - similar scenario to Porter 272, except the handoff from Boston Center was not heard




Offline JetScan1

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Does anyone know how frequencies 134.975 and 128.775 are “mapped out”?

Basically 128.775 extends in an east-west corridor from the Montreal VOR to the Ottawa VOR area (to the charted YYZ/YUL FIR boundary). It covers the T616 and T614 low altitude airways, and the Q824 and Q806 high altitude airways, it's airspace extends up to FL280.

As you noted YOW arrivals via the RIVER9 STAR pass through this sector, as well as YUL depatures via BOBKI and SAVEX. Some YYZ tuboprop arrivals can also be heard routing via T614.

134.975 is the sector directly to the south of 128.775, south of the T614 airway, extending east to the Montreal area, south to Boston Center and west to the charted YYZ/YUL FIR boundary. YUL arrivals via the HABBS3 STAR and YOW arrivals via the DEANS7 STAR pass through this sector, as well as YOW departures via IKLAX.Q844.ART, via KODEX.KAVSU.SAVAL, and via AVVON.T733.

The 126.575 sector borders 128.775 to the north. During normal business hours the 128.775 and 126.575 sectors are usually combined and their frequencies cross-coupled, also included is the frequency at Mont Tremblant. During the day when it's particularly slow they have also been noted to combine the 134.975 sector as well, but it doesn't seem like they do it very often. The transmitters for both 134.975 and 128.775 are located in Ottawa.

During the overnight/midnight shift as you noted they combine all the Montreal low altitude sectors together and cross-couple all the frequencies. They also combine the Ottawa and Quebec City terminals.

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I have determined that frequencies 124.275/135.2 cover areas west and northwest of Ottawa until it reaches Toronto Centre

These two frequencies are always cross-coupled, they are also linked with 135.050. Together they cover all the low altitude Montreal airspace west of the YUL/YYZ FIR boundary, extending up to FL230.

You can pull up the enroute navigation charts here (I don't have any actual sector charts) ...

http://skyvector.com/



« Last Edit: January 02, 2014, 06:24:02 PM by JetScan1 »

Offline janlam01

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Thank you for taking the time in answering my questions. Your knowledge is quite impressive!

I was looking on SkyVector's web site and saw that waypoints BOBKI and SAVEX (for CYUL departures) are just slightly south of airways T614/Q806. Would it be safe to say that the southern border of 128.775 is south of T614/Q806 (covering waypoints KEMVI, KANUR, MELTI) but north of T781/Q921 and T733/Q943?

You also mentioned that 128.775 and 126.575 are usually combined. Have there been occasions where those two frequencies/sectors are separated? If so, where would the northern border of 128.775 be? I know that Ottawa Departures via waypoints RADEN and TAKOL (towards Q941 airway) are usually covered by 126.575 (and I'm assuming waypoint ALIDO on the LEAMY2 STAR as well).

As for Ottawa Terminal and Quebec Terminal being combined, I have noticed during the evenings (and sometimes during the mid-morning hours on weekends). Which leads me to ask, where are they physically located? I find it interesting that Terminal would look after both Ottawa and Quebec City.

Offline JetScan1

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Would it be safe to say that the southern border of 128.775 is south of T614/Q806 (covering waypoints KEMVI, KANUR, MELTI) but north of T781/Q921 and T733/Q943?

Yes I believe this is correct. YUL-YYZ flights route via BOBKI.MELTI.TORNI and use 128.775. So as you say the sector appears to start at a point between TORNI and EPSAT then extend to the east just north of T781/Q921 to a point between MELTI and VERTI then from there to a point between BOBKI and LAFIT. 

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You also mentioned that 128.775 and 126.575 are usually combined. Have there been occasions where those two frequencies/sectors are separated? If so, where would the northern border of 128.775 be? I know that Ottawa Departures via waypoints RADEN and TAKOL (towards Q941 airway) are usually covered by 126.575

I have not heard them being operated separately in recent memory, but then again I have not been monitoring on a regular basis. Given the traffic isn't that heavy in this area I'm guessing the only time they might need to split them up is during times of multiple weather deviations due thunderstorms or when there is holding into YUL/YOW ?

The border appears to extend just north of the T616/Q824 airway. YUL departures via KESKA.BIPKO.IPSAK.OMEGI.RADEN use 126.575 while YUL departures via KESKA.SAVEX.KANUR.LETAK use 128.775.






Offline janlam01

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Would it be safe to say that the southern border of 128.775 is south of T614/Q806 (covering waypoints KEMVI, KANUR, MELTI) but north of T781/Q921 and T733/Q943?

Yes I believe this is correct. YUL-YYZ flights route via BOBKI.MELTI.TORNI and use 128.775. So as you say the sector appears to start at a point between TORNI and EPSAT then extend to the east just north of T781/Q921 to a point between MELTI and VERTI then from there to a point between BOBKI and LAFIT.  

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You also mentioned that 128.775 and 126.575 are usually combined. Have there been occasions where those two frequencies/sectors are separated? If so, where would the northern border of 128.775 be? I know that Ottawa Departures via waypoints RADEN and TAKOL (towards Q941 airway) are usually covered by 126.575

I have not heard them being operated separately in recent memory, but then again I have not been monitoring on a regular basis. Given the traffic isn't that heavy in this area I'm guessing the only time they might need to split them up is during times of multiple weather deviations due thunderstorms or when there is holding into YUL/YOW ?

The border appears to extend just north of the T616/Q824 airway. YUL departures via KESKA.BIPKO.IPSAK.OMEGI.RADEN use 126.575 while YUL departures via KESKA.SAVEX.KANUR.LETAK use 128.775.


Thanks again for your response. I've made an attempt in doing a sketch for both 128.775 and 134.975 on SkyVector, based on your observed info - here is the link: http://tinyurl.com/lycrocj

124.275, 135.200 (as well as 135.05 that you've added) would be west of 128.775 and 134.975.

Let me know how that looks.

Offline JetScan1

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Let me know how that looks.

Yep looks good, that's what I have as well. The only part I'm not sure about is the western part of the border between 126.575 and 128.775. According to an older out of date chart (from Flight Explorer) it shows the border extending from north of OLIGO between the Q848 and Q804 airways towards the northeast between the two airways to a point abeam EBNYR then from there in a straight line through TAKOL to the bounday as you have it depicted. It's hard to confirm exactly were the border is as the sectors are normally combined and there isn't much eastbound traffic on those airways. I'm working on a chart as well I'll post it when I get it done. Listening today so far the 134.975/128.775/126.575 sectors have all been combined with the frequencies cross-coupled. Seems to be the typical weekend configuration.

   

Offline JetScan1

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As for Ottawa Terminal and Quebec Terminal being combined, I have noticed during the evenings (and sometimes during the mid-morning hours on weekends). Which leads me to ask, where are they physically located? I find it interesting that Terminal would look after both Ottawa and Quebec City.

I see they have them combined now. I believe the YOW and YQB terminal controllers are located in Montreal at the Center.

Offline janlam01

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Yep looks good, that's what I have as well. The only part I'm not sure about is the western part of the border between 126.575 and 128.775. According to an older out of date chart (from Flight Explorer) it shows the border extending from north of OLIGO between the Q848 and Q804 airways towards the northeast between the two airways to a point abeam EBNYR then from there in a straight line through TAKOL to the bounday as you have it depicted. It's hard to confirm exactly were the border is as the sectors are normally combined and there isn't much eastbound traffic on those airways. I'm working on a chart as well I'll post it when I get it done. Listening today so far the 134.975/128.775/126.575 sectors have all been combined with the frequencies cross-coupled. Seems to be the typical weekend configuration.
So, I've made a very minor adjustment.
- Extended slightly north of OLIGO
- Went northeast between Q848 and Q804 to EBNYR (but made sure it did was south of ALIDO)
- then crossed TAKOL

SkyVector Link: http://tinyurl.com/mca5xap

Hopefully I interpreted what you wrote correctly. If not, I won't dwell on it further :)

I believe the YOW and YQB terminal controllers are located in Montreal at the Center.
That's interesting - didn't know that before. I wonder what the reason for having Ottawa and Quebec Terminals located in Montreal? One would think that Terminal would be located in the respective city.

Offline JetScan1

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That's closer. Attached below is a screenshot that shows the sectors as depicted on Flight Explorer. This chart is around 8 years old and is a bit of a sloppy job showing terminal control boundaries and low altitude center boundaries, but is the best they have for the area as they don't seem to want to bother updating their database. As you can see since Montreal redesigned the airpace a few years ago most of the waypoints and airways have been changed.   

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I wonder what the reason for having Ottawa and Quebec Terminals located in Montreal?

So Nav Canada can save money. I think they moved the Ottawa terminal to Montreal over 10 years ago now ?

Offline janlam01

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That's closer. Attached below is a screenshot that shows the sectors as depicted on Flight Explorer. This chart is around 8 years old and is a bit of a sloppy job showing terminal control boundaries and low altitude center boundaries, but is the best they have for the area as they don't seem to want to bother updating their database. As you can see since Montreal redesigned the airpace a few years ago most of the waypoints and airways have been changed.   

Thanks for the posting that screenshot - that helps. No worries about the chart being outdated.