More food for thought, particularly after my last post on the "what irks you about ATC" thread. In a procedural environment I work on the principle that both the Dash8 (of whatever variety) and the 737/A320 will take around 8 minutes from 30 miles. There is no way that a DHC8 type turboprop is going to lose to a jet if they are at thirty around the same time. It may be a pain in the ass for the jet doing a step descent but the flexibility of the Dash in the circuit means it is always going to win.
So tonight in Mackay, weather iffy for circling approach, I had computer generated estimates for a Q400 beating a 737, both from the south, by 7 minutes to the field. Both wanted an Rnav approach for Rwy14. No problem, says I to Brisbane en-route, give em what they want. Handover time comes, it's a dead heat. What? I thought there was seven minutes between them? Err, yeah, well, sometimes the computer gets it wrong; how do you want them sequenced? How the hell would I know, says I, not having a clue who is going to finish up in front and by how far.
There was an incredibly long and detailed coordination exercise about what was going to happen, who would be number one, what sort of approach etc, and I found myself thinking, how is this happening? There are only two aircraft in the sky as far as I'm concerned and we're discussing the possibility of making one of them do an orbit at sixty miles! I decide that the 737 will be first cos I can always apply a bit of speed when they call me if necessary. Can you get the 737 through the Dash's level before you transfer them to me? Umm, I think so! The sequence is handed off with the advice that the 737 is reducing speed due turbulence.
Laugh all you want, and in the description it is ridiculous, but it's another example of how decisions have to be made a long time in advance of the event, and despite our best intentions it can go badly wrong. Multiply it by a factor of whatever for full radar environments.
And if the lady who was controlling in Brisbane happens to read this, I'm not putting any **** on you at all! In the end it worked beautifully, but we could equally have finished up BOTH looking pretty silly.
It's a funny old game.