Question for Aussie ATC

[Beg Tibs]

Particularly Brisbane although Im sure the issue is generic..

When flying the Gold Coast arrival into BNE we requested an RNP approach and were told it would be a 4 minute delay. Instead we were given the normal visual approach with no delay.

My question. Both of these approaches use the same waypoints (COTON and LISSA) and for both approaches the times over these waypoints were identical. The tracking after these waypoints is almost identical and the touchdown times were the same.

Im assuming we were not issued the RNP because it would allow ATC more flexibility should they need to take us off track for other traffic..?

Cheers guys and keep up the good work :D

[hermy1]

hi thanks for the query its nice to have com channels flowing.
i'm not aussie ATC but i know in our country we have to have then miles sep behind an a/c doing rnp approach something about ATC not being able to manipulate traffic's speed on the approach.so if you fly a/c that is slower than the rest of the traffic that would have to be increased even more for the faster one behind.so then i can imagine they don't want to hold up faster boys on the downwind until you get closer to threshold.
this is my thumb suck explanation,hope it helps...like i said i don't know much about aussie rules ATC and i don't work at a station that has published rnp approaches.:8

[amberale]

Hi BT,
I'm not quite sure why this happened.
I am BN App/flow.

I'm assuming we were on 01 visuals at the time.
I'm guessing that you were part of a group of like type ac in trail from the same direction. We can pull in a group of four or five ac in a 10mile/2minute trail.
This is our most efficient mode.
We have found that while every ac on RNP flies a slightly different profile they are usually slower than ac on visual approaches.
Also with the low cloud and showers around like today it's not good practice to assume you will get a late sight and follow if you look like losing your 3 miles especially when the pilots have your heads down flying an instrument approach.
That can mean having to pull you off the star if speed control doesn't work.
With the RNP it is harder to get you back onto the approach than it is on a VSA.
Also we are under pressure from noise lobbies/check and standardisation to not cancel STARs over land

That said I would have only expected a 1 or 2 minute delay to facilitate the RNP.
This would have delayed some other aircraft as we make a bit more space around you on RNP so maybe the flow on duty decided to put you at the back of the group if you wanted the RNP.

Sometimes approaches like this can have a follow on effect adding 1-2 minutes delay to a number of following aircraft.
Othertimes, if you are No1 and can do a short RNP in IMC conditions, it might save 20 minutes of combined jet holding.

Hope it helps after all it is a team sport.:ok:

AA