Monople - I don't disagree with anything you said, which is why I think its time to scrap PTL's, but
If our 'schedule' states we will have them returning to Perth
As an airline you are providing a service that relies on a third party, finite resource, RWY space. A travel agent can't sell more tickets than there are seats on your plane, and we can't have 40+ arrivals in one hour. Your schedule has to be realistic, and collectively, airlines are making promises that cannot be kept. Which was the point of PTL's, to make the schedules possible by limiting demand to capacity.
A 1 hour ground delay for a 1.5 hr to 2 hour flight. Thats just plain rubbish.
The length of the flight doesn't factor (maybe it should?) For example, 30 scheduled arrivals in a one hour period, single RWY ILS approaches (20 arrivals an hour) and you are number 30, scheduled to land at 0100. At 0100, only 20 of the 30 have landed, leaving 10 to go at 3 minutes each, you get a half hour delay. Now lets say its 40 scheduled (not uncommon), you've got an hour, 45 scheduled and its 75 minutes. It adds up very quickly.
Maybe we need to go a step further. Rather than airlines submitting their schedules each night as a wish list, and then getting a ground delay, maybe slots need to be allocated on a more strategic level, i.e. when the schedules are being written, or monthly or something.
Now in a sensible world, capacity would be increased to meet demand, but I think we can assume thats not gong to happen. It would be an interesting exercise to work out how much delays cost the airlines and then work out what you cold get by spending the same upgraging the airport.
The one grain of comfort in all this is that while the service may be rubbish, no one's complaining about safety.
