VATNZ - VATSIM New Zealand

I have been sent a few concerns from controllers and pilots regarding a lack of positive control whilst they are taxiing at New Zealand airports.

I'd like to first discuss how Ground Control is handled in the real world and then how I'd like to see it handled on VATNZ.

In the real world there are two distinct areas on an a controlled airfield. One is called the "Manoeuvring Area" and the other is called the "Movement Area". The Manoeuvring Area is that controlled by ATC and requires a clearance to enter and conversely, the Movement Area is uncontrolled and does not require a clearance. As a general rule, the Manoeuvring Area covers taxiways and runways and the Movement Area covers aprons, including gates, stands and maintenance bays. The reason for the split is that it would be far far to complicated for ATC to issues clearances for every single tug, baggage cart, fuel truck or catering truck to enter the apron area. The Movement Areas are displayed in the AIP on the Aerodrome and Ground Movements Pages for controlled Aerodromes. Have a look if you are not familiar with this.

At large international airports, the Movement Area can be "controlled" (I use that term loosely because they are not controllers and therefore cannot issue clearances) by something called "Apron" or "Ramp Control". These people are employed by the airport company or airline to watch over the ramp area and ensure that aircraft do not collide whilst taxiing to the gate or pushing back from the gate. There is an Apron Control at NZAA for the International Terminal.

I have only seen an Apron position once on VATSIM and that was in the USA during an event at KATL (Atlanta). Generally speaking we do not use an Apron position, therefore, in most parts of VATSIM controllers either do not say anything about starting up and pushback or they may use the phrase "push back and start up at your discretion". There is no clearance authorisation word in there so it's not a clearance.

However - and there is always a catch, most large New Zealand airports were not designed to allow aircraft to push back and remain within the movement area (if such a thing existed when they were built). Those of you who are familiar with Auckand or Christchurch Domestic Terminals will be aware that jets end up pushing back onto a taxiway. In these cases, an authorisation to enter the manoeuvring area is going to be required before pushing back. Because the aircraft is in the movement area first but a clearance is required, controllers will use the phrase "push back approved" and will ensure that there will be no collision on the taxiway. To add to the confusion, even though there is room on the Wellington Apron to pushback without infringing taxiways, the Ground Controller still issues pushback approval because the whole apron is a huge mess of gates.

So where does that leave us at VATNZ?

Regional:

There are no gates at our controlled regional airports so there is no need for pushback approval, only "start up approved, time now xx".

International Towers:

Although you wouldn't normally mimic the Apron control for Auckland's International Terminal, it will be much easier if we just handled all jets the same at AA, WN and CH. So if an aircraft needs a pushback, we say "pushback and start up approved, time now xx".

Positive Control:

If you advise that an aircraft can push back onto a taxiway (e.g. onto B from ANZ Domestic at AA), you cannot simply just say to another aircraft "Taxi to holding point A1, Runway 23L via B, B5 and A, caution 737 pushing back from gate 31", for example. There is no positive control in there at all and it will lead to all types of confusion. You will either need to use taxiway A or B with a hold short to ensure that the aircraft is well clear of the pushbacking aircraft e.g.

"Taxi for Runway 23L via B, hold short of B6"

The same applies for arriving aircraft vs. pushbacking aircraft.

In some cases it may be more advantageous to hold the pushbacking aircraft until a taxiing aircraft passes behind. You can use:

"Behind the 737 on B, pushback approved, behind".

This is very similar to a conditional lineup clearance.

Positive Control on taxiways:

It's also no good to give a departure from the International Terminal taxi via A for Runway 23L and just issue an arrival vacating at A6 "taxi to the gate".

Either you use:

"Behind the 777 on A, taxi to the gate behind" or

"KAL129, taxi for Runway 23L via A, hold short of A6"

and allow the arrival to taxi to the gate, or just wait until the 777 passes the arrival to issue the taxi clearance for the gate.

If you have two departures, one from International and one from Domestic, you need to use the phrase "follow" when issuing a taxi clearance to whichever one you want second. Obviously if they are miles away then there is no need but if the Intl departure is abeam B6 on A and the domestic calls for taxi you need to issue a "follow"
e.g.

"ANZ501, follow the company 767 on A, taxi to holding point A2 Runway 23L, via B4 and A". (note the follow comes before the taxi clearance)

"Use caution" or "caution 767" is not good enough.

Ground Control isn't as easy as it is made out to be. If anybody has any questions please let me know.

Cheers,

David