I am sorry but you twisted my statement I said APPARANTLY not flying a quadrantal, I did not say that anything had been BROKEN.
I interpreted your comment:
The big skies theory is great if everyone flies to the same set of rules, unfortunatly yesterday it proves that they do not!
as suggesting that the other aircraft wasn't flying to the rules. But I take your main point.
WCollins wrote:
My own view is that if aircraft flew at a level determined by the last letter of its registration (thus introducing more randomness) it would be more effective, but, as I keep saying, there really is no problem.
I heard of a proposal many years ago that the big hand on the altimeter should match your heading (e.g. NE at 1000s + 125 ft). It provides only 500 ft of separation between opoosite direction, but it seems to meet sensible criteria. Perhaps we should add a die to the requirements of Scehdule 4
Finally, IO540 wrote:
It would make an interesting exercise in probability theory to work out whether IN IMC a mid-air is more or less likely between two objects flying head-on or the same two objects flying in the same direction.
It's a good question. One way of looking at it might be to consider a flight 1 from A to B taking 2 hours at 150 kt, and a flight 2 from B to A, taking 3 hours at 100 kt. They will pass if the difference in their departure times is in a 5 hour window (i.e. if 1 leaves at 1400, it will conflict if 2 departed between 1100 and 1600). If you reverse flight 2, it will conflict only if it leaves in a 1 hour window (1300 to 1400).
While that's a 1-dimensional look at a complex problem, but I think it illustrates the point.