ASRC - Observer's Guide

(version 1.2 - November 2003)

This page will show you how to log on to VATSIM using ASRC and Roger Wilco, and how to make the most of being an observer.

Before you start, make sure you have a VATSIM CID (Controller Identification number) and password, and have joined the UK Division. Details of how to do all this are on the "Getting Started" page.

Guidance for downloading and installing ASRC and Roger Wilco are on the "ASRC Setup" page. The combined Installation and Observers Guide can also be downloaded in Word format as ASRC Observers Guide.doc

 Logging on  Observing with text  Observing with Roger Wilco Using Private Chat

Logging on

  1. Open ASRC.
  2. If you have voice enhancements enabled Roger Wilco will open automatically. If you are not already online RW will open your dialler dialogue. When you connect you will be connected to the internet, but NOT to Vatsim.
  3. If you do not have voice enhancements enabled the dialer will not appear until you reach the OK button in the ASRC connections box.
  4. In ASRC select File/Connect. A dialogue box will open.
  5. Enter your callsign. When you are controlling this will be the callsign of your position, but as an observer you can choose your own. It is recommended that you choose something by which you can be recognised online, such as your initials or first name, followed by _OBS. eg RUTH_OBS, RM_OBS.
  6. Leave the Tag box blank.
  7. Set the Rating box to your official Vatsim rating. If you are just starting out this will be Observer.  You can only log on at a higher rating when you have passed the appropriate exam. Observers can watch and can take part in private chats, but cannot communicate on ATC radio frequencies.
  8. Enter your real name in the appropriate box.
  9. Choose one of the servers from the drop down menu to log in. If you only have the default list of the US and UK servers you will need to have updated the list first
    1. The easiest way is to use the ServInfo programme. Use File/Export ipaddr.txt and save the file in the ASRC root directory (where your asrc.exe is installed).
    2. If you do not have ServInfo you can obtain a recent copy of ipaddr.txt from the ASRC/resources page on the Essex website.
  10. Facility should be set to Observer.
  11. Enter your CID and password.
  12. Press OK, and you will be connected to VATSIM. If you are not already online, your dialler dialogue should pop up automatically.
  13. You will now see aircraft positions appear on the map. You have successfully logged on!


Observing a controller on text

You now need to choose a controller to observe. The best position for a beginner to observe is a Tower (TWR), because these control all the take-offs and landings, and if there is no Ground controller available, they will also give the clearances and taxi instructions. You can also observe the Approach (APP) and En-route (CTR) controllers, who will be giving specific headings, flight levels and speeds for aircraft already in the air.

Look at your radar screen and identify any airports that look reasonably busy. If you have ServInfo, you can see how many aircraft are due to fly in and out. In ASRC the Controller List is in the upper right section of the screen. This lists the active controllers and observers in your visibility range. This will be centred on London Heathrow (EGLL) unless you have changed the "centre on" setting. The visibility range is set in the Options/Settings menu.

What do those codes mean? The main airport codes can be found on the "Useful information" page. For example, Stansted is EGSS, and Luton is EGGW, so Stansted Tower is EGSS_TWR, and Luton Ground is EGGW_GND. Controllers using voice put a V in their callsign eg EGSS_V_TWR. Other abbreviations you may see are T(rainee), M(entor), (R)adar and E(xaminer).

  1. In order to observe a controller you need to connect to his ATC frequency using the VSCS (Voice Switching and Control System).
  2. Click on the controller's callsign in the controller list. In the CRD (Computer Readout Display) in the bottom right hand corner of your screen, the controller's details will appear in the middle RA (response area) box. On the first line will be the controller's callsign and the ATC frequency e.g. EGSS_V_TWR 123.800. Make a note of both.
  3. Open the VSCS by pressing TAB or using the drop down menu. The grey boxes are called "frequency buttons", and each can be set to one ATC position.
  4. Click on BUTN CNFG on the bottom line, and then on the first available grey box.
  5. In the dialog box enter the frequency (eg 123.800), the name you want on the button (eg Stansted Tower or EGSS_TWR), and the RW Channel (normally the same as the Callsign eg EGSS_V_TWR). Click on OK.
  6. The box will now turn white and will be labelled with its name. Click on the box to open it.
  7. There are three coloured boxes. From left to right these are Transmit, RW connection, and Receive. Green means ON, and black means OFF. At the moment only the right button (receive) should be on. Anything that is typed on this frequency by the controller or the pilot will appear in the transparent textbox at the bottom of the screen. As an observer, you will not be able to input anything yourself.
  8. You can check you are connected correctly by looking at the bottom of the screen. The frequency you are connected to is displayed in yellow text (receive mode only) surrounded by a red box (voice mode off). You may not see very much text communication at all, as most pilots and controllers use voice, so it is worth setting up Roger Wilco as soon as possible.
  9. You will get a better view of what is going on if you use the sector file for the airport you are observing. This shows the taxiways, runways, buildings and boundaries in detail. If you followed our "Getting started" instructions, you will also have the Essex Radar sector file. To open the Essex Radar file, click on File/Open, and then navigate to your sector file folder. To centre your screen on a particular airport just type the four letter ICAO code and then press the <home> key.
  10. All the Essex RAM sector files are available on the Essex website. Other files can be obtained from the Downloads page of the Vatsim-UK website.


Observing using Roger Wilco (RW)

Most controllers and pilots use voice, as it is easier and quicker. However, please note that voice and text are given equal priority. Text is also used as a backup when voice transmissions are of poor quality.

  1. Each controller uses a voice room, identified by the server IP address and the controller's callsign e.g. You can only observe a controller on voice if you are connected to the same voice server. Most UK controllers use the UK2 voice server ( If you followed the instructions above this is what you will be connected to. You can see which voice server you are connected to by looking at the Options/Settings menu.
  2. To find out which server a controller is using, you need to read his ATIS (Automated Terminal Information Service).
    1. Type .atis <callsign> (the . is important).
    2. You will see the callsign in the Controller List start flashing. Click on it and press the Controller Select (csel) key. If you haven't changed the defaults this will be the \ key.
    3. A grey box will appear near the bottom of the screen with the ATIS in it. If it scrolls past too quickly, use <pageup> to scroll back. You can turn the grey box off by pressing \ again.
    4. Make a note of the IP address and RW callsign; note the latter is sometimes different from the text callsign.
  3. If you are connected to the same voice server you can join the voice room. If not you will need to change to the correct server (see section 4 below). To join the voice room:
    1. Open the VSCS (drop down menu or TAB)
    2. Use the BUTN CNFG to check that the RW callsign is correctly entered in the third box of the configuration dialogue.
    3. If the frequency button is closed (the box is white) click on it to open it.
    4. To open the Roger Wilco channel click on the middle box which will turn green.
    5. At the bottom of the screen the box surrounding the frequency will change from red to green. You are now connected to the voice room and can listen to the controller and pilots talking.
    6. Make sure the left xmit (transmit) button is black (off), so that you do not accidentally transmit on the controller's frequency.
  4. To change the voice server
    1. Open the VSCS (drop down menu or TAB), and close any open voice connections by ensuring that the middle boxes of all the open frequency buttons are black (off).
    2. If any are green (on), click on the relevant boxes to turn them off, or close the frequency boxes.
    3. Change the Voice Server in the ASRC Options/Settings menu. If you have left any voice connection open, the voice server box will be greyed out and you will be unable to change it.
    4. You may now connect to the new controller's frequency (see section 3 above).

RW etiquette. The only people speaking in a voice room should be the controller and the pilots. Observers MUST maintain radio silence. The only exception is when there are no pilots in the voice room, when the controller may choose to use voice with an observer rather than text. This is highly unofficial, and if a pilot comes on frequency, must be stopped immediately. Consult the manual on how to use VSCS to transmit.


Using private chat
Observers can communicate with other people online by using the private chat facility.

Receiving a text call

  1. If you have an incoming message the letters "CL" at the top of the controller list (top right of the screen) will flash yellow, and the background behind the caller's callsign will flash grey.
  2. To view the message, click on the callsign. You can also select the callsign by typing the two character ID to the left of the callsign and then pressing the controller select <csel> key. This will be \ if you haven't changed the default setting.
  3. A grey text-box will appear near the bottom of the screen with the incoming message displayed. The identity of the caller will be displayed in the RA (response area) box at the bottom right of the screen. The currently selected individual in the controller list will have a white box around the callsign.
  4. The chat-box must be grey in order to type in it. To reply just type your answer in and press <enter>. If you press <enter> without typing anything in, the box will turn black. To turn it grey, press <enter> again.
  5. To change to another person you already have communicated with, just click on their callsign.
  6. To close a chat-box, press the <csel> key.

Initiating a text call

  1. To open a chat-box with anyone in the controller list type the two character ID to the left of the callsign and then pressing the controller select (csel) key. This will be \ if you haven't changed the default setting.
  2. The grey chat-box will appear. Anything you type will then be sent to that individual.
  3. Their reply will appear in the chat-box.