Separation Standards and RNP 10
 

Couple of questions for you ATCers out there from a pilot

1. What is the minimum separation you allow between two RNP 10 aircraft? I understand that the RNP 10 requirement is to be within 10nm but does that mean you allow a separation of 20nm betwwen two RNP 10 a/c or do you add a buffer in there as well?


2. What is the minimum separation you allow between a RNP 10 a/c and one that is not?

The separation in radar environment doesn´t have anything to do with your navigation capability. (depends on the radar system and procedures in use)

In procedural environments and cases with "deemed separation" between airways it might make a difference somewhere. I dont know of any procedural separation standard based on RNAV though...


But there are surely more suitable persons than me to answer on the last part :ok:

It is a bit more complicated than 10 + 10 + fudge factor, have a look at a cogent explanation - Required Navigation Performance - Wikipedia, the free encyclopedia

RNP10 means the nav error of the aircraft will not exceed 10 NM for at least 95% of the time. That is not enuf tolerance for ATC standards, which require 99.something or other%. To get that level of containment you need a circular error of position of 25 NM, put your RNP10 aeroplanes 50 NM apart and they are separated. Don't need a buffer.

There are other same direction standards that let you get closer than that, and radar is better.

And that's exactly the separation used in the Oakland Oceanic FIR at least, 50 NM laterally between two RNP10 aircraft. It's still time-based longitudinally, 10 min standard, which can be reduced using mach technique.

Thats great guys, thanks for the replies! Should keep the students happy in my next course!