|Have a look here to see who pays how much to the doorman...
https://www.torontopearson.com/en/Airpo ... and_Fees/#
We had a slot allocation back into YYZ for 10pm the other night from YOW. Called clearance about 8.30 for a 9pm departure and was told because of flow, our new wheels up time was 10.49pm! Then listened for the next 2 hours whilst every AC/Encore got the requested time they wanted with no more than 20 mins delayed at the most. YYZ was VFR and they were using the 33's. I even heard an AC guy call up and say he wasn't going to make his slot time and they called him back with a new slot for 15 minutes later, and our time was still over an hour away.
Whilst I understand the current limitations due to the runways, this seems a little one sided as far as delays. The biggest issue is managing clients with anything from a 30min to 4 hour delay. Better stock up the booze and snacks
The best rate on 33 is 42 planes per hour, depending on the number of lights & heavies. This consists of 36 on 33L and 6 offloads onto 33R, which then delays departures while they wait for the lander. The number of offloads can be dynamic depending on the balance of arrival vs departure demand.
Unless your flight plan was filed into the system before the GDP was published (there is always lots of notice to file prior), you will get an arrival slot at the end of the program. Occasionally, GDPs are run with a "pop-up factor" which allows room for extra slots within, but when the system is constrained this much, a small or zero factor is applied. Thus, last minute filers can encounter larger total delay regardless of their celebrity status or how many fat stacks they're willing to lay down.
The airlines you heard are getting the times they requested, because they know in advance from their dispatch what their departure slot time is. For example, the flight was scheduled at 800 and gets an atc delay until 930, that flight knows to delay boarding etc. and call up and request 930. It only seems that they are getting what they requested, but the delay is roughly the same as everyone else's. When you see aircraft getting just a handful of minutes after they requested, it's either done to reduce the airborne holding volume at destination by pushing things back, or to accommodate a company aircraft off another airport that couldn't make its time.....see below:
In terms of missing a slot, with hundreds of flights and code share partners, the airline dispatchers are able to use what is called a "slot credit substitution". It allows both them and ATC to trade slots with their other flights. For example, because of a boarding delay, flight 123 can't arrive at 1900, so it will trade that arrival slot with flight 456, who was supposed to arrive at 1915. 456 then gets to depart earlier and preserve a duty day, or someone already airborne gets a shorter hold.
If you think keeping one VIP happy by feeding beer and pretzels, assigning blame to faceless air traffic control, and ordering a limo is tough, just imagine trying to balance the priorities of 1500 daily flights with dispatchers swapping times due to crew duty day issues, aircraft missing slots due to boarding, baggage or mechanical issues, aircraft not departing on time due to inbound traffic, runway inspections or deicing, missed approaches taking up a slot, 2 airlines that want to run a different operation from the 3rd which conflicts with atc priorities of traffic management, adjusting to changing winds, weather, and runway operations, all the while ensuring that there is always enough airborne inventory so slots aren't missed, and there aren't too many planes holding to overwork the enroute controller, with pressure from the customers to up the rate, and pressure from the tower to allow more room between arrivals for contingency, on your 9th 12hr day in a row just to make the system work and then being criticized by a special snowflake.