Actually the separation standard is 1 nm.
Tolerences are then added to this dependant on the airspace and surveilance system.
So in TMA within 50 nm of a radar head the tolerences applied to each "paint" are 0.8 nm.
0.8 + 0.8 = 1.6 + 1nm for the separation = 2.6. This is rounded up to 3nm.
In enroute the tolerences are 1.6.
1.6 + 1.6 = 3.2 + 1nm sep =4.2. Rounded up to 5nm.
Those tolerence figures are approximate. I'm a long way from my copy of the books but you should get the idea.
Outside of radar/ADSB coverage the standards are 20nm or 10 minutes longitudinal.
Lateral [I think, it's been a long time since wielded a spanner]
30nm either side of track for DR.
That is 61nm between aircraft tracks at the same level.
8nm either side of track for Rnav
That's 17nm between aircraft tracks at the same level.
If no one is looking at the radar which standard should it be gauged on?
AA
Last edited by amberale; 18th Jul 2008 at 10:58.