Transponder help for a newbie

[Ian Ashton]

Hi to all,

I had my first flight on Vatsim a few days ago, not the best RT I have done, but thankfully got through it without any massive faux pas on my part!

My question is regarding airfields without "live" Vatsim controllers (maybe offline etc)

This is IFR

I assume I still file a flight plan, and announce intentions (and listen) at obvious stages on Unicom etc.

What do I squawk mode C as ATC would normally assign? Do I squawk a generic 7000?

Thanks in advance

Ian

[Joshua Jenkins]

First of all, welcome to VATSIM!

6 minutes ago, Ian Ashton said:

This is IFR

I assume I still file a flight plan, and announce intentions (and listen) at obvious stages on Unicom etc.

Yes that's correct.

7 minutes ago, Ian Ashton said:

What do I squawk mode C as ATC would normally assign?

CoC B4 states: "A pilot shall not squawk standby while their aircraft is in motion except when requested by air traffic control. Simulation of aircraft without a transponder is permitted with air traffic control approval." (source: https://www.vatsim.net/documents/code-of-conduct)

So if you have an aircraft with a transponder squawk mode C when taxiing (different airports and regions have various regulations on this stage of flight and your transponder mode but that's a topic for a different thread), taking off, or landing.

10 minutes ago, Ian Ashton said:

Do I squawk a generic 7000?

The squawk code isn't really all that important if ATC is offline. 2000 is "The code to be squawked when entering a secondary surveillance radar (SSR) area from a non-SSR area used as Uncontrolled IFR flight squawk code." Used in ICAO countries, Canada, Australia and US (source: https://en.wikipedia.org/wiki/List_of_transponder_codes). 2200 is typically for oceanic airspace. 7000 is the VFR squawk code in ICAO countries (comparable to 1200 in the US or Canada).

I hope that clarifies your questions and once again welcome to your new favorite hobby 😜

Cheers!

[Andreas Fuchs]

1 hour ago, Josh Jenk said:

2200 is typically for oceanic airspace.

2000 is normally the code to be set 30 minutes after entering Oceanic airspace. Wikipedia shows both SQ2000 and SQ2200 for Oceanic operations. The North Atlantic is definitely using SQ2000.

Edited December 8, 2020 at 10:39 AM by Andreas Fuchs

[Joshua Jenkins]

Good catch. I thought something was wrong about that when I posted it. Guess that's what happens when you try and reply to forum topics at 2AM.

[Andreas Fuchs]

Hi Josh, but you were not wrong! Wikipedia lists both codes for Oceanic airspace, for SQ2200 referring to some FAA document. I have not verified it, maybe it is true, maybe not. In the real world (Europe/Africa/MiddleEast in my case) we always set SQ2000, unless a discrete code has been assigned to us.

[Joshua Jenkins]

I believe this is the section in the FAA document that the Wikipedia article references. If I understand it correctly, oceanic is always 2000 unless ATC assigns  one of the other non-discreet codes or a discreet code.

[Ian Ashton]

Thanks to everyone for your help, this is a steep learning curve! (even with over 3000hrs of real flying experience VFR)

In the sim, I am only flying short hops in Europe, in and out of the UK, no pond crossing yet. I was just confused regarding what to squawk and set as an ID without ATC.

So, if I am understanding this correctly:

Only squawk Mode C during taxi, take-off and landing (but why would ATC require altitude info when taxiing?)

Turn off once airborne, UNLESS  I enter an ATC zone, in which case they will assign and ID. Is this correct please?

If I then leave ATC control, I assume I then turn off Mode C/Transponder?

Sorry, so much to ask!

 

[Andreas Fuchs]

Hi Ian,

activating transponders is a thing of recent years, because most, if not all, large airports do have a ground tracking system for traffic. They receive your Mode-S signal and get your flight shown on their ground radar map. Therefore it has become SOP to switch ON transponders at least in mode "ALT OFF" (if available), otherwise to "ALT ON", once you are ready to move from your parking position. Basically we do it once we have received out ATC clearance with a discrete transponder code: set code and select ALT OFF/ON. Only when entering a runway for your actual departure will you switch it "full ON", in our jets that would be "TA/RA" to also activate the TCAS. After landing, this will be reverted from TA/RA to ALT OFF/ON once the landing runway has been vacated. Only when on stand will the transponder be set to STBY.

Here on VATSIM you will do the same, because we also simulate "ground radar" and when you depart outside active airspace, just set SQ2000 for IFR flights and SQ7000 for VFR and MODE C/ALT ON (or whatever your plane can do). Keep it like this until you land or until ATC assigns a discrete code to you.

Edited December 8, 2020 at 01:53 PM by Andreas Fuchs

[Tomas Hansson]

No, transponder needs to be set to Mode C whenever the aircraft is in motion. So turn on when you start taxiing at your departure airport and turn off when you arrive at the gate/ramp at your arrival airport.

 

(Edit: Andreas was quicker.)

Quote

B4 - A pilot shall not squawk standby while their aircraft is in motion except when requested by air traffic control. Simulation of aircraft without a transponder is permitted with air traffic control approval.

 

Edited December 8, 2020 at 02:01 PM by Tomas Hansson

[Andreas Fuchs]

Yes, in VATSIM that is effectively Mode C. Some addon aircraft allow you to select several transponder modes (STBY, ALT OFF, ALT ON, TA, TA/RA, IDENT button). Practically, we only simulate STBY, Mode C and Ident, so ALT OFF, ALT ON, TA, and TA/RA are all Mode C for our purposes.

[Andreas Fuchs]

2 hours ago, Josh Jenk said:

believe this is the section in the FAA document that the Wikipedia article references. If I understand it correctly, oceanic is always 2000 unless ATC assigns  one of the other non-discreet codes or a discreet code.

 

oh, brilliant, thanks for looking this up. I will make a change request to that Wikipedia page.

[Joshua Jenkins]

1 hour ago, Ian Ashton said:

Turn off once airborne, UNLESS  I enter an ATC zone, in which case they will assign and ID. Is this correct please?

If I then leave ATC control, I assume I then turn off Mode C/Transponder?

Sorry if my initial response was confusing Ian. I think Andreas and Tomas hit the nail on the head quite well with following up on my explanation.

 

10 minutes ago, Andreas Fuchs said:

oh, brilliant, thanks for looking this up. I will make a change request to that Wikipedia page.

Awesome! Correct information is always a plus.

[Ian Ashton]

Thanks to all for taking the time to respond, really appreciated. Yes, the first response from Josh was a bit confusing!! but I now understand.

Safe flights everyone, and thanks again

Ian