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Lesson 3 - Aerodromes with full ATC Service


This is a series of tutorials and practical flying exercises prepared by the CIX VFR Club to introduce members to online ATC and to enable them to learn at their own pace how to use it. Each lesson consists of a Groundschool section on aviation law and theory, and a Practical exercise to fly using the information in the Groundschool.

There are three basic types of Air Traffic Control with which Club members flying under Visual Flight Rules (VFR) will need to know about.

  1. Air Traffic Control (ATC).
  2. Aerodrome Flight Information Service (AFIS).
  3. Air/Ground radio (A/G).

For this lesson, we will examine the first, and on VATSIM, the most important type.

Aerodromes with a 'full' Air Traffic Control Service

This lesson describes procedures at Aerodromes (Note: not Airports - such as Heathrow or Manchester) where an ATC service is provided and where the aerodrome does not have a large area of controlled airspace surrounding it, but only the standard 2 miles radius 'Aerodrome Traffic Zone' (ATZ). The Club bases at Gloucestershire, EGBJ, and Biggin Hill EGKB, are aerodromes with a 'full' ATC service. Others which the Club uses, and which have ATC services on VATSIM by arrangement are: Carlisle EGNC, Shoreham EGKA, and Lydd EGMD.

VATSIM operates a “top down” system where more the qualified controllers manning Radar positions can provide a Tower service at aerodromes within their area. For example, Thames Radar can offer a service to pilots arriving and departing from Biggin Hill as well as controlling traffic in the wider Thames region. This will be covered more fully in later lessons.


Read Chapter 3 of the Club's Air Traffic Control Manual for VFR Pilots which may be found on the web site in the Training section, Tutorials subsection. ATC_for_VATSIM VFR Pilots.pdf

In addition you may wish to obtain a copy of the CAA official publication, CAP 413 'The Radiotelephony Manual' which contains every official ATC instruction and response. (CAP by the way stands for Civil Aviation Publication'). This is available to download completely free from CAP413 However, don't be frightened off by the huge amount of information it contains. You will be guided in these tutorials in the important parts needed. Possibly as little as a quarter of the total contents are applicable to Flight Sim and VATSIM.

With certain exceptions, an Air Traffic Control service provides pilots with instructions both on the ground and airborne. An Air Traffic Control Officer (ATCO) at an aerodrome with an ATZ gives instructions to all aircraft on the ground, on the active runway, and airborne to outbound aircraft within the ATZ, and to inbound aircraft within about 10 miles or five minutes flying time whichever is the greater.

They can also offer a Flight Information Service (FIS) to en route aircraft within 40 nautical miles of the aerodrome, but this isn't well known and not often used. VATSIM controllers may therefore not offer a service if you contact them and are not landing at their aerodrome.


After start up and before taxiing, the pilot should obtain (and write down) the 'Automated Terminal Information Service' (ATIS) broadcast where provided, particularly noting the designation letter (information Bravo in the example below). The frequency is given in the usual flight guides or on the CAA's AIS Aerodrome charts.

For FS and VATSIM, this procedure is slightly different. Where there is a separate ATIS frequency given, you can receive a voice broadcast in the same way as in the real world, except that it sounds more like a human being (because it was a human being recording it).

If there is no voice ATIS, then when you tune the Controller's frequency, the ATIS text will be displayed on your FS screen scrolling across the usual green banner. Also, if you click on the ATC position name in Squawkbox or FSInn, it will be displayed in a separate window.

With ATC, as with AFIS, your ground movements are controlled, so you must request permission to taxi.

Gloucester Tower: Golf Bravo November Oscar Zulu: Request radio check on wun two two daycimal niner zero and taxi [instructions] with information Bravo.

Golf Bravo November Oscar Zulu: Reading you strength 5: Taxi to holding point Charlie. QNH 1012.

Under ATC control, you must read back all instructions, so: -

Taxi Holding point Charlie, QNH 1012: Golf Bravo November Oscar Zulu.

Engine run up and vital actions may be completed at the holding point, or at designated run-up areas. ATC will advise if a run-up area is used (as at Carlisle, for example). When these checks are complete, you are ready for your next instruction.

Golf Bravo November Oscar Zulu: Ready for Departure

Note that it is not 'Ready for take off'

What ATC say next can vary depending on circumstances, but will eventually include the words:

Golf Oscar Zulu With a right turn out cleared take off runway 22

It is illegal to take off until given an instruction which includes the exact words 'cleared take off' (the runway number will vary of course). You MUST NOT take off until you have had that instruction, and you MUST read back at least the words 'Cleared Take Off' and your callsign.

Cleared take off runway 22 Golf Oscar Zulu

Note that the callsign used has been abbreviated part way through the dialogue. Officially, in the real world, and therefore on VATSIM, the pilot must not abbreviate his callsign until the controller has done so first, but to be honest, this rule is not enforced rigorously and you will hear a number of variations. Where is does matter is where there are two aircraft with similar callsigns working the same frequency, e.g. G-ACIX and G-BCIX, two Club aircraft. Then the controller will invariably ask both aircraft to always use their full callsign.


The instructions to inbound aircraft will be given for positioning purposes, e.g.

Golf Bravo November Oscar Zulu, join overhead for runway two seven, right-hand circuit, QNH 1011, report overhead

All of that is an instruction, which the pilot should obey except if to do so would place his aircraft in danger or in illegal flight conditions (e.g. flying into cloud). As you continue round the circuit to land you will be given further instructions. Then, as you turn onto the final approach, you call

Golf Oscar Zulu final [Runway 22]

In a similar way to departure, you MUST NOT land unless given the explicit instruction

Golf Oscar Zulu Cleared to land Runway 22, Surface wind 210 8 knots.

Note that the ATCO gives you also the runway to land on, by way of confirmation - pilots frequently make approaches to the wrong runway - and the surface wind.

You MUST repeat back

Cleared to land Golf Oscar Zulu

Note that you do not read back the wind, and reading back the runway is optional. If you do not receive a 'Cleared to land' instruction then you MUST initiate a missed approach and rejoin the circuit for another attempt. This is as true on VATSIM as it is in the real world which we are trying to emulate. Specific landing and take off clearances are only required at aerodromes with full ATC.

There are many more possible instructions, all listed in CAP413. Learn as many as you can which are applicable to CIX VFR Club flights, and practice them almost anyway you like. The Club offers one to one ATC voice practice, which can be a good starting point.


In lesson 2, you positioned your aircraft at Barton Aerodrome and practiced some simple R/T exchanges. This time, position an aircraft at either of the CIX VFR Club bases on its appropriate evening and log into VATSIM. Let the Club CFI know that that is what you intend to do, so that he can be on hand to offer advice, if necessary. There should be traffic using the aerodrome, inbounds, outbounds and circuit traffic. Simply sit and listen to the dialogue between the ATCO and the aircraft.

Club Bases

Remember that Thames Radar can offer a service to pilots arriving and departing from Biggin Hill as well as controlling traffic in the wider Thames region, so if Biggin Hill isn't on line, look for Thames Radar in Servinfo or VATSpy.

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