Toronto Terminal Control Unit using NORTH-DEPARTURE freq 127.575

[StarTheAvgeek]

I am normally used to hearing YYZ Terminal Departures on the South frequency (128., but I was archiving a few audio clips from a incident that occured on February 3rd 2024 at approximately 1152 UTC, and after the incident aircraft (EDV4826, a CRJ) reported an electrical fire and started descending, the controller gave handoffs to the north frequency, which I've never heard them using as far as I've heard.

I find it quite interesting, let me know what you guys think.

[SkyViking]

127.57 is used during busy periods especially summer afternoons and evening if enough staffing in the tower permits simultaneous departures from both the north and south parallels then the terminal opens a second departure freq. hence 128.8 caters to the 6-24s and 127.57 handles 5-23 departures, very similar when 124.47 opens up if there are a lot of inbounds at the same time. However with regards to your question if an actual fire emergency has been confirmed by the crew and 132.8 was already handling a slew of arrivals they could have made a quick decision to give EDV4826 an unused frequency to quickly get them back without interruptions from any other aircraft communications.  It's as simple as turning on a toggle switch to begin communicating with the aircraft in distress.

[StarTheAvgeek]

That makes a lot of sense, thank you very much for the reply.