Vertical Separation.

[Noah Zark.]

Can anyone help, please? I'm not in the "Biz", just a dedicated enthusiast.
This afternoon, I was watching two airliners, in a beautiful clear blue sky, flying over me, and directly away from me.
At first, it seamt that they were flying parallel to each other, and they were abreast of each other.
In fact, their paths converged, until one passed directly over the other one. I know that they were not really close to each other, and the angle I was then viewing them at exaggerated the fact.
What I would like to know is, what would their vertical separation have been? (Quadrantal rule?)
Thanks. N.Z.

[Notso Fantastic]

2000' minimum going the same way.

[Noah Zark.]

Thanks for that, Notso.
Regs. N.Z.

[Capt Claret]

Noah,

Here in Dunnunda minumum separation would be
1000' if below Flight Level 290 (FL290), 1000' if above FL290 and both aircraft were RVSM approved (Reduced Vertical Separation Minimum) 2000' if above FL290 and either one or both aircraft were not RVSM approved.

[eyeinthesky]

Quote

2000' minimum going the same way.

Unquote

Not necessarily. They could have been 1000ft apart waiting for the cross to continue further climb.