Is it just me or have you ATC folks picked up the pace for arrivals and departures out of YYZ lately? Are there new separation rules or something helping you launch and land aircraft faster and tighter?
We've been cleared to take off at times that I thought there was no way it'd be allowed with someone on final and vice versa had guys take off in front of me while on approach much closer than before. Either way it's been impressive and a job well done from my vantage point.
YYZ is getting steadily busier and over the past month or so, 06R/24L has been closed so we've been mixed mode on the other two from 06:30-22:00 which, when there are 100+ flights in an hour, is a lot of work for not just the tower guys but ground as well. There are now noticeable bulges in demand especially for departures. 9pm is probably the biggest, even on a Saturday there are close to 40 departures scheduled at 9pm which, if it happens to coincide with an arrival push, means line-ups. 11pm is another little push.
The most efficient way to get rid of departures when there are no arrivals is to sequence jet/prop/jet/prop etc and when arrival spacing permits there may be the opportunity to sneak a prop out right behind a jet in gap that two jets could not use. That's probably what you've noticed.
There are no new rules just timing and opportunity. Two jets on the SID need to be 3 miles in trail when the following is switched to departure. That is what slows down departures especially off 33R in a 30kt headwind when there are guys flying the NADP1 and grounding 110kt until 3600ft.
A little bit of a headwind helps too as does that early turn from the DH8As and jets willing to perform like they do south of the border.
During the afternoon/evening I think we've used 33R from B1 for the north bound Dashes less than we have in the past because 05/23 has been busier and North Ground is sometimes too busy with taxying traffic and/or gate holds to make it work in an advantageous fashion. When 06R/24L comes back into use it should ease the arrival load on 05/23 so the flexibility there might come back.
Some of us have been inconvenienced by Dashes asking for 33R at B1 and then not being ready when they get there. When the horde comes out at 2245 that's the ideal time as there are a bunch of heavies heading for 23 too and when traffic permits and the tower guy agrees, I've experimented with sending 33R in the PDC. That seemed to keep things moving better.
Sometimes you just have to go to 05 with the rest of them. H2 and H4 sometimes work well but other times they can be a hindrance if you have to go after jet traffic from the full length as it takes time to get on the runway as they roll by whereas you would be in position and ready earlier at the threshold. Still no harm in asking.
Departing 23 when the 33s are in use? Let me think....
OK you'd be departing from H because B would have traffic on it that had landed on 33L or perhaps 33R;
You'd have to roll through the gap between departures off 33R and be through the intersection of 33L a mile away between arrivals spaced 2.5 miles (50 seconds) apart. Without LAHSO (something that has gone out of use here) that one is more difficult, maybe even impossible to do unless you were flying something much, much faster. Sorry, its a non-starter.
We have departed medevac traffic on 23 from F which the arrival controller only has to fit through his traffic, or 05 from F which the departure guy does. Direction of flight is also a factor. We can't go off 23 to the E or SE as we would have to turn right to avoid the arrivals which would shut down 33R for a time. Same with 05 to the W or S would turn left. Its all about overall efficiency not just what benefits one user, which is why I added medevacs to the first sentence.
Have you ever departed 24R or 24L southbound when everyone else is going to 23 and all the arrivals are on 24R? Saturday afternoons is the prime time for this one.
Or departed 24L when we're landing and departing 23 and 24R? I did this a couple of days ago around 9pm with a Q400 and a 1900.
Or landed on 6R from an approach to 33L? Not done that in a while.
There are a few scenarios that have been tried but it all comes down to timing and opportunity. Not getting to speak with an arrival until about 4 final doesn't give much time to put all the pieces in place to allow a landing on a different runway. We're not going to do something out of left field to benefit one user if it is to the detriment of others and certainly won't do it if the risk outweighs the reward. Safety is still number one on our list.