Nothing sinister VH-CU,
MAESTRO works everything out based on your estimate for the threshold, applies the landing rate (set by the flow) and works out the order and the delay needed for each and every aircraft. MAESTRO picks it based on the estimate nothing more or less; this is why it's important to have an acurate TAS in your Flight Plan, the FDR works the estimate from your flight planed TAS, Grib winds and a 'predicted trajectory'. all these things may be inaccurate so that is why it doesn't always get it right, but it applies the same method to all so law of averages says it gets it mostly right.
If you get a mates rate (defined offline who gets them, Med1 etc; flights from Continental USA, Africa etc. aircraft in an emergency scenario, MIL VIPs etc.) we need to remember who gets priority otherwise it doesn't always workout correctly.
MAESTRO works everything out on 'planned' times taken from our FDRs. It is very flexible (sometimes not!) but is getting smarter every upgrade. Aerodromes such as Canberra - Sydney; get put in the sequence based on a slot time for departure; which is a strategic decision but often needs to be modified in a tactical way to ensure slots are not lost; this can be tricky.
If 7 aircraft are arriving at 0831 in the morning, maestro will pick the order; but if you speed up ever so slightly you may go from number 7 to number 1. The order is stabilised about 30 minutes before landing... But things can still change for tactical reasons.
When we start applying a delay early; it's because we've taken the order and 'frozen it' so that variations in the FDRs don't affect the entire order. If you've got 7 aircraft at 0831 and a 2.5 minute landing rate number 7 needs about a 15 minute delay; get in early if you can rather than just go to holding, right? Sometimes of course there is nothing at 0829 so we start making 1st go fast etc. and tighten the line behind.
There are different Mates Rates too, Zero Delay applied, 5, 10, 15, 30 maximum applied. Sometimes we give a MIL VIP Zero Delay, establish a line behind that aircraft and then get a call that "we need to meet a specific on blocks time"; which means 3 or 4 need to get in front, embarrassing if you’ve just finished applying the delay already; answer usually means slots lost…
The classic slow down, now speed up scenario.
Another reason for the slow down then speed up is "separation"; often pilots assume we could have just given an interim speed instead of the too slow speed; but this doesn't always work for 'separation' it's not always just about the sequence, hey QFA94?
Last edited by SM4 Pirate; 7th Sep 2005 at 02:58.