Can TCAS be used in lieu of sighting and passing?
No, there are no separation standards based on TCAS (yet!). This is another reason for doing the passing OCTA. The crews can use logic and maths to establish when they are clear of each other, we have to use Separtion Standards (allegedly devised using logic and maths but with a lot of probability and legal but-covering thrown in).
The main considerations are the climb/descent profiles and how far out the passing will happen, bearing in mind the inbound aircaft has priority.
To get up before, 10 minutes prior to time of passing, nothing else.
I think thats worth emphasising. There are NO distance (DME,GPS etc) standards for opposite direction traffic.
or the flaky VFR procedures some pilots could not bring themselves to use
I thought VFR climb was the only good thing about NAS and we lost it. Especially for the 146 out of NRV held down by an opposite direction F50 at F190 over 100nm away AND on radar.
"Clearance not available, remain OCTA"
"Request VFR climb"
"Roger climb to F240 VFR, no traffic"
"Climb FL240"
