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Basic ATC Manual

The Basic ATC Manual gives an overview of simulated Air Traffic Control precedures, practices and general informaition for us in VATSIM-UK operations.

Revision history
16 March 2006. Changes to reflect the implementation of Class C airspace in the UK.
16 June 2006. Revision to reflect VRC functionality. These changes are primarily of a minor editorial nature and therefore NOT highlighted in yellow.
15 February 2007. Changed to reflect the introduction of Class C airspace above FL195 in the UK.

• Air Traffic Control Mission
• Advanced Simulated Radar Client
• Controller Positions and Functions
• ASRC Flight Strips
• Handoffs
• ATIS - Automatic Terminal Information Service
• Metars
• Squawk Codes
• Airspace
• Control Techniques
• Emergency Operations
• Tips and Techniques
• Final Advice

Air Traffic Control Mission

The primary purpose of the ATC system is to prevent a collision between aircraft operating in the system, and to organize and expedite the flow of traffic. The same holds true in the simulated environment.

The primary objectives of the air traffic service shall be to;

• prevent collisions between aircraft in the air;
• assist in preventing collisions between aircraft on the manoeuvring area and obstructions on that area;
• expedite and maintain an orderly flow of air traffic;
• provide advice and information useful for the safe and efficient conduct of flights;
• notify appropriate organizations regarding aircraft in need of search and rescue aid, and assist such organizations as required. Obviously this objective is of limited applicability in the VATSIM environment.

Advanced Simulated Radar Client

ASRC adds real time air traffic control to flight simulations through a worldwide network of servers.

ASRC provides;

• Realistic display for use by ATC positions from ground through to centre contoller
• Interaction with live simulator pilots via text and voice
• Multiple communication channels for the most realistic experience. Coordination with other controllers via private text messaging

Before logging on to a control position it is MANDATORY that students acquaint themselves with the functions of the ASRC system. ASRC and its associated Operating Manual are available here. You must read this manual and be aware of what ASRC can do before logging on to the network.

A guide to getting started can be found in the TRAINING department under Starting Out.

Aircraft Target and Info Blocks

Aircraft in ASRC can display on the radar display in many formats depending on the type of radar display selected. Unless you are logged on as GND or TWR then only the DSR and ARTS options are available. DSR is customarily used for AREA (CTR) operations, ARTS is customarily used for Airfield Approach control (APP) positions. The symbols shown on the various display formats are fully explained in the ASRC manual.

In addition to the target on the radar display some basic information is provided to help you judge the aircraft speed and position. This is called the data block and again is explained fully in the ASRC manual.

In addition to the info block and target you will see a trail of dots behind the aircraft showing its recent positon history, this is useful for assessing the aircraft's track and ground speed. You may also see a line extending out in fron of the target. This line is the projected path of the aircraft and is based on the position history and ground speed. By default ASRC projects one minute ahead but that can be changed using the on screen menus as explained in the manual.

Although voice communication facility is built into both ASRC and Squawkbox3 you must also be able to control effectively using text only. This will be greatly eased by the use of an alias file in ASRC optimised to your own requirements. The ASRC manual has detailed instructions on the use of alias files.

A sample alias file is available in the downloads section of VATUK website. This should be modified to suit your control position.

Controller Positions and Functions

Below is a basic summary of each Air Traffic Control position and their functions.

Ground Controller (GND)

The Ground Controller is responsible for exercising general surveillance and control of aircraft on the airport movement area, excluding active runways and high speed runway exits. A Ground Controller will issue general information; Pushback and engine start clearances, taxi instructions and IFR Clearance to aircraft.

A full and detailed study of a Ground Controllers Functions is contained in the AERODROME GUIDE.

Tower Controller (TWR)

The Tower Controller is responsible for the surveillance of the active runways and traffic operating by visual reference to the surface in the vicinity of the Aerodrome Traffic Zone. If there is no ground position then Aerodrome control assumes this function as well. Tower determines the active runway and controls all arriving and departing aircraft. In addition Tower is responsible for VFR aircraft within the immediate vicinity of the aerodrome.

Arriving IFR aircraft do not come under Tower control until the aircraft is number one to land or is operating by visual reference to the surface. IFR arriving aircraft may be in communication with TWR prior to this point but TWR is NOT controlling these flights, they are merely in communication with them.

A full and detailed study of a Tower Controller's Functions is contained in the AERODROME GUIDE.

Approach Controller (APP)

The main function of the Approach controller is responsibility for all IFR flights arriving at and departing from an airport, though in certain locations the Approach Controller may be responsible for more than 1 airport.

The Approach Controller is responsible for the separation of aircraft and this is no more important than for arriving aircraft at busy airports. In the UK, Approach will generally be responsible for traffic within 30Nm of an airport and up to FL120. If there is no CTR service available then APP may operate to an absolute maximum of 40Nm up to FL240. Arriving aircraft once established on the Glide-slope would normally be transferred to the Tower Controller but Approach is still responsible for the safety and separation of such flights until they become number one to land.

In certain locations and at busy times the Approach Controller is assisted by a Departure Controller (DEP). This position handles all departing aircraft, providing the link between Tower and Centre Controllers, leaving Approach free to concentrate on arriving aircraft.

The Approach Controller's position can also be split even further into a geographically-based group e.g. West Approach (responsible for aircraft arriving from the west) and East Approach (arrivals from the East). Certain locations also introduce a Final Approach Controller at busy times, responsible for the final separation and sequencing of arriving aircraft.

The work of an Approach Controller will be extensively covered during a student's mentoring.

A full and detailed study of an Approach Controller's Functions is contained in the APPROACH GUIDE.

TMA Controllers (TMA)

The TMA controller is responsible for the control of aircraft after departure until hand off to Area Control (CTR) and for arriving aircraft prior to those aircraft commencing their approach. PRecise details of each TMA position are contained within the relevant sections of the VATUK web site (e.g. Manchester TMA is detailed within MACC section).

TMA controllers are only established at busy locations (London, Manchester and Scottish TMA). They provide an important link between Centre Controllers and Approach Controllers.

The work of a TMA Controller will be extensively covered during a student's mentoring.

Centre Controllers (CTR)

The Centre Controller is responsible for all IFR aircraft within the ACC airspace. Primarily a Centre Controller will be responsible for the en-route phase of an aircrafts flight. Centre also becomes involved in dealing with aircraft at unmanned airports in accordance with VATSIM UK "Top Down" policy.

A Centre Controller may also offer Radar Advisory Service (RAS) and Radar Information Service (RIS) to IFR and to VFR aircraft operating outside controlled airspace subject to workload.

The work of a Centre Controller will be extensively covered during the later stages of a student's mentoring.

Other ATC positions

Above are the Main controllers positions. There are, however, others which you may see from time to time. These include:

Eurocontrol

Euro Control handles all traffic where there is no Centre or Approach available. For example EUR_W_CTR will provide ATC for most of continental Europe and Eire. There are no arrangements for the Eurocontrol sectors to control UK airspace.

Flight Information Service Stations

There are two types of Flight Information Service Station. Flight Information Service Stations using the callsign _I_CTR provide a non radar service including pilots briefings, relay of clearances, issue of squawk codes, weather conditions at airports and any other information useful to the safety of aircraft.

Flight Information Service Stations using the callsign _FSS (such as Eurocontrol or Oceanic) provide a control service to flights covering a vast expanse of airspace where the limitations of ASRC require the use of the suffix FSS in order to provide long range surveillance and radio communications.

Clearance Delivery (DEL)

Clearance Delivery issues ATC clearances to flights prior to their starting up at busy airports. This function is only at major airports to relieve the loading on Ground controllers.

Air Traffic Services Outside Controlled Airspace

As mentioned in the Centre Controllers Responsibilities and Functions above, RAS, RIS and FIS can be provided subject to workload. This is not restricted to Centre controllers, many Approach units provide these services as well. A more detailed look at these ATC functions can be found on the ATSOCAS document

ASRC Flight Strips

The flight strip used in ASRC gives all the information you will need about an aircraft's flight. Each block is explained below.

The first line shows the aircraft´s callsign, what it will call itself over the radio. Almost all airlines (and of course Virtual Airlines) use a company designator, in this instance BAW is British Airways so the flight will be called Speedbird Zero Zero One.

The next line of information shows the aircraft type, in this instance it is Concorde.

Next we have the True Airspeed and Ground Speed. Do not confuse the two. The first is the actual speed through the air at which the pilot intends to fly; trust me, many sim pilots have no REAL idea at what True Speed their aircraft will fly, so treat this figure with suspicion. The Ground Speed is the speed at which the aircraft is actually covering the ground. It is measured by the radar system and is a true figure, but of course it has been affected by the wind, so do not worry about the difference between the two; Ground Speed is a more accurate measure if you wish to determine whether one aircraft is catching another. In the above example, T1180 is the true speed requested (Mach 2), and G0 is the radar calculated ground speed. In this case stationary. In other words it is on stand.

The bottom line shows the Computer Ident Number. This number can be very useful as a short cut to entering information about the aircraft but remember that this number is unique to your PC, other controllers will have a different CID for the aircraft. The 01 is a version number and will rarely be anything other than 01 in the VATSIM environment. It can be ignored.

The top line here shows that the aircraft is IFR, the alternate of course is V for VFR.

Next is the departure and destination airfields, in this case EGLL - London Heathrow to KJFK - John F Kennedy, New York, USA. If a pilot has nominated an alternate (the airfield he intends to fly to should he be unable to land at his planned destination) it will be shown below the primary departure and arrival airports.

The next two boxes show firstly the current ATC allocated level and secondly (lower right hand side) the pilot's requested cruise level. These will normally be expressed as Flight Levels but not always so.

Now we have the route to be flown - The pilots intended/requested route of flight (to be discussed in other sections during your training). The whole route will be shown in this area unless it is particularly long in which case this box would simply display "Route too long"

The bottom line of this box is the remarks section. This can include sections detailing whether the pilot has voice capability (indicated by /V/) and other comments inserted by the pilot.

The final box contains the SSR code allocated to the flight by ATC, this may not be the same as the code the aircraft is actually squawking! Also in this box is an ATC Scratchpad entry. ATC may enter any useful information here if it can be contained within three characters. If no information has been entered then this will normally show the flights planned destination code (which is 4 characters generally).

Handoffs

A handoff is an action taken to transfer the radar identification and contol of an aircraft, from one controller to another.

Provided that an aircraft is being transferred from one controller to another in accordance with a Standing Agreement (SA) then the handoff is simply accomplished by using the automated handoff facility built into ASRC (F4 function). In order to be able to use this facility it is essential that all aircraft which are in the air and under Control from ATC are "tracked" using the F3 facility.

Where a Standing Agreement does not exist, or an aircraft has to be transferred other than in accordance with the SA, then individual Controller to Controller co-ordination MUST take place. This can be via PM on ASRC or by direct voice communication on Teamspeak

When handing off an aircraft which is not on a SA it is important to let the receiving controller know of any instructions you have given to an aircraft, using the same medium as used for the co-ordination process. At the same time it may be necessary to tell the pilot to report such instructions to the next controller. A common example of this would "report your radar heading to London Control on ".

It is most important that you ensure ALL CONFLICTS are resolved prior to handoff.

The method of initiating and accepting a handoff is detailed in the ASRC manual.

Automated Terminal Information System (ATIS)

In Real World ATC an ATIS is the continuous broadcast of recorded weather and other non-control information.

In the VATSIM environment the principal purpose of ATIS is to provide the voice channel information so that the pilot clients (Squawkbox and FSINN) will autotune the appropriate server and voice room. It is also important to set this information even if an individual controller is not voice rated.

To set your ATIS in ASRC open the Options/Settings menu and type the relevant information in the ATIS box.

The following information must be included in your ATIS:-

• $mypvtrw
• $radioname() $freq()

ATIS information SHOULD be limited to maximum 3 lines of information and MUST NOT exceed 4 lines.

NOTE: In the real world, the METAR is included in an ATIS. This information MUST NOT be used in ASRC unless it is in the abbreviated format $metar(eg**) replace the asterisks with the appropriate letter for the airfield you are working.

METARS

A METeorological Actual Report (METAR) is a report giving the actual weather at a given airport. METARS are issued every 30 minutes or more frequently if conditions require. The weather conditions found in ASRC are based on real world METARS.

A METAR report contains the following elements:

1. Station identification
2. Date of the month and time issued
3. Surface wind direction and speed (possibly with variations in either direction or speed)
4. Visibility
5. Present weather
6. Cloud coverage
7. Temperature and dew point. (°C in Europe)
8. Airfield QNH
9. Recent weather
10. Trend forecast

If the visibility is 10 Km or more, there is no cloud below 5,000', no Cumulonimbus cloud at any level and no significant weather then items 4, 5 and 6 will be replaced by CAVOK.

In conditions of low visibility (1500M or less) Runway Visual Range (RVR) may be added after the main visibility element.

Trends are only issued at major airports.

The following is a breakdown of the main METAR elements:

EGLL 291020Z 31015G27KT 280V350 1200 R27R/1000 +SHRA FEW005 SCT010CB BKN025 10/03 Q0995 RETS9 BECMG FM 1100 27030G50KT

1. Identification

2. Wind

3. Visibility

4. Runway Visibility

5. Present Weather

Combinations of up to 3 elements could be present in the Present Weather group

6. Cloud

7. Temp/Dew point

8. Pressure. QNH

Qindicates pressure in millibars. If A were used the QNH would be in Inches and 100ths. The UK always uses millibars

9. Recent Weather

For weather to be classed as REcent it must have started and ceased since the last routine observation

10. Trend

Trend indicates how the weather is going to develop over the next two hours. Trends are only issued at major airports

Example;

EGLL 301220Z 24015KT 200V280 8000 -RA FEW010 BKN025 OVC080 18/15 Q0983 TEMPO 3000RA BKN008 0VC020

Decoded;

London Heathrow at 1220 UTC on the 30th; Surface wind 240deg, 15kts varying between 200 and 280 deg; prevailing visibility 8km; light rain; Cloud few at 1000ft broken at 2500ft overcast at 8000ft; Temperature +18deg C Dew Point +15deg C; Trend temporarily 3000m vis in moderate rain broken at 800ft overcast at 2000ft

In the UK wind shear is not reported but is used in other countries. Windshear is not replicated from METARS on MSFS.

Squawk Codes

Squawk codes are issued to aircraft as part of their ATC clearance, as well as issued to Aircraft entering an ACC airspace.

Also known as SSR (Secondary Surveillance Radar) or Transponder Codes, a Squawk Code is a radio identity code that allows a specific aircraft to be identified on a radar scope.

In ASRC a Call sign is shown on radar by default if the full data tag is displayed, unless an aircraft's flight plan has not been sent in which case ASRC would just display the aircraft Squawk Code or if the aircraft is squawking the code which has been set in the ASRC "Options/Settings" menu as the VFR code it will display just as a letter "V" (for VFR).

Squawk Codes are allocated according to a set of rules defined in the UK AIP, which change from time to time.

Controllers are encouraged to make use of a utility entitled ATCA (Air Traffic Controller's Assistant) - available from the VATUK Downloads section, which looks up the appropriate code from a central database and avoids code duplication as much as possible.

Flights which will remain close to their original airport may be allocated a discreet code appropriate to that airport, again these codes can be accessed via ATCA.

Special Purpose Codes

The following codes are reserved for emergency situations as described:-

• 7500 - HIJACK (See important note below)
• 7600 - Radio Communications Failure
• 7700 - Emergency (Mayday)

Code 7500 MUST NOT be used on VATSIM. Selection of this code by a pilot will result in an IMMEDIATE forced disconnection from the network.

Conspicuity codes

The following codes may be used in the situations described if no other code has been allocated by ATC:-

• 7000 - General UK VFR squawk
• 1200 - VFR squawk allocated by default in Squawkbox3
• 2200 - IFR squawk allocated by default in Squawkbox3
• 2000 - Operating in an environment where no radar surveillance is available (e.g. North Atlantic Ocean)

Airspace

This section will go into some detail in regards to Airspace classifications. The airspace in the UK from the surface up to FL600 is divided into two Flight Information Regions (FIRs), the London FIR and the Scottish FIR. The boundary of control from London to Scottish does NOT follow the divide between London and Scottish FIRs! In real life these are further subdivided at FL245 into lower and upper FIRs, but VATSIM-UK FIRs do not divide in this way. The London FIR is further divided into London ACC and Manchester ACC.

There are 2 types of flights:-

• IFR, where Instrument Flight Rules apply and
• VFR, where Visual Flight Rules apply.

Controlled Airspace

Controlled airspace is airspace of defined dimensions within which Air Traffic Control service is provided in accordance with the airspace classification.

ICAO classified airspace in seven classes, denoted by a letter from A to G where Class A represents the highest level of control and Class G is uncontrolled airspace. Class B is not used in the UK.

Class E airspace is not implemented on VATSIM-UK, Class E airspace is treated as Class D for simplicity.

Controlled airspace is also that airspace within which all aircraft operations are subject to certain pilot qualifications, operating rules, and equipment requirements.

• For IFR operations in any class of controlled airspace, a pilot must file an IFR flight plan and receive an appropriate ATC clearance. Standard separation is provided between all aircraft operating under IFR in controlled airspace.

• Pilots flying VFR are responsible for ensuring that ATC clearance and radio communication requirements are met prior to entry into Class C and D airspace. In class F and G airspace, where clearance is not required it is RECOMMENDED that pilots make their presence known to the appropriate ATC unit.

• Pilots wishing to fly IFR in Class F airspace are strongly urged to file a flight plan with ATC and to take advantage of a Radar Advisory Service which will provide Separation against other participating IFR flights and will attempt to provide Separation against all other flights.

Airspace Classification

As mentioned above in the UK Real World Airspace Class A represents the highest level of control , whereas Class G is uncontrolled airspace. Class B is not used in the UK and Class E is not reproduced in VATSIM UK.

Class A Airspace

In Class A airspace all flights must be operated in accordance with IFR. Class A is the highest level of controlled airspace usually allocated to the busiest airspace (Heathrow Control Zone and all Airways). Not available to VFR

Class C Airspace

Class D Airspace

IFR and VFR flight permitted, all flights are subject to ATC service. IFR flights are separated from IFR flights and receive Traffic Information on VFR flights which are less than the prescribed Standard Separation minima away from them. VFR flights may receive Traffic Information on other VFR flights.

Class F Airspace

IFR and VFR flight permitted, flights are not required to avail themselves of an ATC service but are strongly recommended to do so. Participating IFR flights are separated from other participating IFR flights and receive Radar Advisory Service (RAS) against all other flights. VFR flights may receive Radar Information Service (RIS).

Class G Airspace

IFR and VFR flights are permitted and may receive RAS RIS or FIS depending on the type of service being offered, flight rules and ATC workload.

Summary - IFR

Summary - VFR

Air Routes

There are two fixed route systems established for Air Navigation. They are Lower and Upper Air routes.

Lower Air Routes

This system consists of airways designated from varying base levels up to FL245. These airways are depicted on En Route Low Altitude Charts.

High Altitude Air Routes

High Altitude Air routes are established from FL245 upwards. These routes are designated by a U (e.g. Upper November 864 is UN864, and is a major Airway into or out of UK airspace.

Requirements for VFR Flights

Weather Minima for VFR flights within Class C Controlled Airspace.

• 8km flight visibility; 1500m horizontally from Cloud; 1000ft vertically from cloud

Weather Minima for VFR flights within Class D Controlled Airspace.

At and Above FL100

• 8km flight visibility; 1500m horizontally from Cloud; 1000ft vertically from cloud.

Below FL100

• 5km flight visibility; 1500m horizontally from Cloud; 1000ft vertically from cloud
• Fixed wing aircraft at or below 3,000' AMSL with an IAS of 140 kts or less 5km flight visibility Clear of Cloud and in sight of the surface.
• Helicopters at or below 3,000' AMSL Clear of Cloud and in sight of the surface.

Weather minima for VFR flights Outside Controlled Airspace (Class F and G Airspace)

At and Above FL100

• 8km flight visibility; 1500m horizontally from Cloud; 1000ft vertically from cloud

Below FL100

• 5km flight visibility; 1500m horizontally from Cloud; 1000ft vertically from cloud

At or below 3000' AMSL

• Fixed wing aircraft flying at more than 140 KIAS 5 Km visibility clear of cloud and in sight of the surface.
• Fixed wing aircraft flying at 140 KIAS or less 1,500m visibility clear of cloud and in sight of the surface.
• Helicopters Clear of cloud and in sight of the surface.

Control Techniques

Airspeed

ou should always be aware that ASRC displays only ground speed for aircraft. It is important to keep that in mind before reminding a pilot of speed restrictions you have issued. In a no-wind situation the pilot's indicated airspeed will be lower than what you see on your display. due to the difference between Indicated Airspeed and True Airspeed especially at higher altitudes, it is up to you to compensate for the difference, and not assign an unreasonable airspeed restriction.

Indicated Airspeed

The aircraft's airspeed indicator depends on the effect of air being forced into a small tube mounted on the outside of the aircraft (pitot tube). This airspeed indication is affected by the density of the air, which changes with altitude and ambient air temperature. As the aircraft climbs the air becomes less dense and the airspeed indicator shows a lower speed than the aircraft is actually moving through the air. Pilots rely on indicated airspeed to control the aircraft, because it is a true representation of how the aircraft will behave in respect to stall speeds and other known aircraft characteristics.

True Airspeed

True airspeed is the speed the aircraft is actually moving through the air. It has no aerodynamic relevance, its only purpose is to be able to calculate ground speed after having allowed for wind effect in the flight planning stage.

Ground Speed

While true airspeed is the speed an aircraft moves through the air with no regard to the wind, ground speed is the speed the aircraft is moving over the ground. So remember that the speed you see on your radar is ground speed, and the speed the pilot normally sees is indicated airspeed. Your speed will usually show a higher value than the pilot's, depending on his altitude, unless he has a strong headwind. Unfortunately, some pilots display true airspeed instead of indicated airspeed because it is one of the FS options. Be aware of that possibility when an aircraft appears to slow considerably below an assigned airspeed restriction.

Speed Restrictions

In the UK an airspeed restriction applies of a maximum of 250kts below FL100.

This restriction may be lifted by the Controller in Controlled Airspace. It is NOT permissable to cancel this restriction in class F or G airspace. For example if it's quiet and there are no traffic conflicts it may be desirable to lift the restriction for a departing aircraft, once it's established on its SID. By the same token Controllers are advised to keep the restriction in force to ensure separation of traffic at busier times or locations.

Cruising Level

Level Assignments

A level assignment is one of the required elements of an IFR clearance, in many cases the initial level assignment will be an altitude whereas the final level assignment will be a Flight Level. The assignments are, of course, made with the purpose of helping you to keep all aircraft separated. IFR vertical separation rules for subsonic aircraft are:

• Up to and including FL410 - 1,000 feet.
• Above FL410 - 2,000 feet.

For aircraft at supersonic speeds the above figures must be doubled. This refers to the aircraft's CURRENT speed, not the speed it is capable of, so a concorde flying at subsonic speed is only subject to the normal vertical separation criteria.

Direction of Flight

Cruising levels are allocated according to the aircraft's Direction of Flight. For all controlled Airspace, Cruising Flight Levels will be allocated according to RVSM rules. RVSM stands for Reduced Vertical Separation Minima, and replaces to older requirements which existed from FL290 to FL410. All Flight Sim aircraft are assumed to be compliant with RVSM criteria.

RVSM level allocation

VFR Aircraft are subject to the same cruise level requirements in Class B airspace.

There are of course exceptions to this rule which you will be taught during your more advanced training, but as an example UN864 between DCS and BHD, the track of the air route is Westerly according to the above but uses Easterly levels as the rest of UN864 (beyond BHD) is Easterly. The reverse applies from BHD to WAL on the same route.

Some air routes are designated as "one way" routes, however the same rules for cruising levels still apply.

The direction of flight rules are intended for the en-route phase of flight during normal circumstances. They do not apply to aircraft being vectored in a TMA environment or to Approach Control situations; however if an aircraft is to be levelled off for any length of time during its climb or descent it makes sense to follow the "Direction of flight" rules above.

Navigational Aid Limitations

Navigational aids can be classified as almost anything, visual or otherwise, that give an aircraft positional data. For our purposes the limitation we are concerned with is the useful range of VORs, DMEs and NDBs. VORs without DME are becoming a rarity, and most navaids, except for DMEs, have distance information available. With a DME if you are receiving the correct ident coding and a distance readout it can be considered to be useable and accurate.

Radio navaids have a published coverage in terms of distance and sometimes altitude. This takes into consideration signal strength, their protection from navaids on the same frequency, and other factors. The coverage of any radio navigation aid is published in the UK Air Pilot in the en route section. GENERALLY FS radio navigation aids comply with the limitations defined as above, but if a navigation aid is being received together with the correct morse ident in FS then it can be assumed to be correct and useable.

Controllers should beware of asking a pilot for position information relative to a radio navigation when the aircraft may be beyond the useable range of the facility. FS2002/2004 also replicate low altitude reduction in coverage, that is to say an aircraft which is on the ground will not pick up a VOR twenty miles away, but should receive it by the time it is at an altitude of 1,000'.

RNAV Operations

RNAV is short for aRea NAVigation, and does not rely on ground based pinpoint navigation aids but is capable of navigating the aircraft to a published waypoint which is identified only by latitude and longitude co-ordinates.

Area Navigation capability is mandatory for IFR flight in Controlled Airspace and MSFS already has an inbuilt RNAV capability in the GPS system. Many other third party RNAV systems are also available for the Flight Sim pilot so there is no reason why any sim pilot should not be able to navigate direct to a waypoint fix.

Position and Altitude Reports

Position reports are normally only required in a non-radar environment. Sim Pilots should not be asked to report position when being tracked on radar except for a specific purpose. For example a busy controller wants to be reminded when the aircraft reaches a certain position.

Although a Tower Controller has radar display it is often appropriate for him to ask for a report from the pilot when the aircraft is passing 4 miles from touchdown to allow him to ensure there is no departing aircraft on the same runway, and then issue landing clearance. In the same way it is necessary for a landing aircraft to report "Clear of Active Runway", so that Tower can get departing aircraft lined up on the active runway, ready for departure.

Emergency Operations

An emergency can be either a Distress or an Urgency situation. The definition of a Distress situation is one of being threatened by grave and/or imminent danger and requiring IMMEDIATE assistance. A pilot who considers himself to be in this situation must make a call prefixed by the word "MAYDAY" transmitted three times. An Urgency situation is one where the pilot is concerned for the safety of his aeroplane or passengers but does not require IMMEDIATE assistance, just priority over other traffic. In this situation the pilot must make a radio call prefixed by the words "PAN PAN" transmitted three times.

An emergency can be declared by either the pilot or the controller. If you believe that an aircraft is encountering an emergency situation, you can declare an emergency. If the words "Mayday" or "Pan-Pan" are not used and you are in doubt that a situation constitutes an emergency or potential emergency, handle it as though it were an emergency.

Because of the infinite variety of possible emergency situations, specific procedures cannot be prescribed. However, when you believe an emergency exists or is imminent, select and pursue a course of action which appears to be most appropriate under the circumstances and which most nearly conforms to the instructions in this manual.

Except during an Exam situation ALL emergencies on VATSIM UK are at the controllers discretion. If a pilot declares an emergency other than during a practical exam and you do not feel that you can adequately cope with the emergency without inconveniencing other traffic it is acceptable to require the pilot to either cancel the emergency situation or to disconnect. This option is NOT to be used simply to avoid handling an emergency, it should only be used if handling the emergency will significantly inconvenience other system users.

Obtain enough information to handle the emergency intelligently. Base your decision as to what type of assistance is needed on information and requests received from the pilot because he is the only person in full posession of the details of the situation. Hopefully, you will already know what type of aircraft and its position. Some other information you should try and obtain is:

1. Nature of the emergency
2. Number of persons on board
3. Fuel remaining in time
4. Pilot´s request or intentions

It is very important to let the pilot know you understand his (emergency) status. The correct phraseology is: "ROGER YOUR MAYDAY/PAN".

Radio silence should then be imposed on the frequency if it is a MAYDAY situation using the phrase, "All stations except MAYDAY traffic - cease transmitting - OUT." Once the aituation is resolved or the aircraft is transferred to another frequency radio silence should be cancelled using the phrase, "All stations MAYDAY traffic ended at time **** OUT"

When you receive information about an aircraft in distress, forward detailed data to the centre in whose area the emergency exists. Remember, the pilot has a lot of things to do. He is still trying to keep the airplane flying and/or control the situation. So don´t be upset if he is unable to give you all the information you request. Don´t pester him about it, just assist him the best you can.

If it appears likely that you will need to transfer the aircraft to another frequency then be sure to advise that controller in plenty of time. If at all possible do not ask the pilot to change frequency, but relay messages from other agencies as necessary.

When an emergency occurs on or in the vicinity of the airport, control other air and ground traffic to avoid conflicts in the area where the emergency is being handled. All runway movements should be cancelled if an inbound aircraft is in a distress situation. This is to ensure that no other aircraft can become disabled on the runway thereby requiring the emergency aircraft to divert.

Emergency Squawk code is 7700, all aircraft in distress should be asked to squawk 7700 but it must be remebered that this will not be high on the pilot's priorities.

HIJACKED AIRCRAFT

It is absolutely forbidded to simulate a hijack situation on VATSIM network.

Tips and Techniques

Contoller Conduct

It is extremely important to realize that this is a simulated environment. Many mechanical-type problems can take place ranging from internet congestion (lag) to excessive frequency usage. It is very important to remain calm while working. You will find that the more you work, the easier the information will be to pass.

Here are some key points to remember while controlling:

• Sometimes when you have issued an instruction the pilot may not immediately acknowledge. That does not mean that the pilot did not get the instruction. It may be that there is lag or another type of problem. Reissue the instruction after a few seconds to ensure the pilot receives it. Remember, the pilot has to fly the aircraft first and foremost and possibly type into SquawkBox at the same time if not voice equipped.
• Be patient with new pilots. Some pilots are just as nervous as you and are not adept at flying, let alone flying and using SquawkBox. If you encounter a novice pilot, make the instructions short, with plenty of time in between them. An experienced pilot will let you know if you are invading his expertise. However, you will find that experienced pilots will help you out a lot more, so don't get upset if they tread on your professional feet. They are just trying to help.
• If you encounter a problem pilot, contact an online supervisor. This is accomplished by typing .wallop followed by a message which will be delivered to all supervisors and administrators currently logged on to the network. Normally, a supervisor will come to your assistance if there is one available. You should never argue with a problem pilot or let your temper direct your actions.
• If you find yourself being overwhelmed don't be afraid to ask for help. It is better for an experienced controller to give you tips than to let the situation snowball. This is a learning experience for all and the smoother the operation, the more information you will retain.
• Utilize chat windows with other controllers that are in your area. This is essential for rapid coordination. If another controller is being a problem, also report it to a supervisor or Administrator.

Working with unstaffed adjacent centre airspace

Naturally, the real ACCs are staffed all the time , and the answer to this problem will not be found in the the manuals. Some experienced sim controllers handle more than one centre under light traffic conditions, but it can be very difficult. You must not control adjacent ACC airspace unless there is a formal provision in place for this. Even where arrangements do exist to control adjacent airspace (e.g. EGTT_N_CTR can control MAN_CTR airspace directly below it) the most reasonable thing to do may be to not control in adjacent ACC airspace, and to concentrate on your own responsibilities.

If an aircraft calls you for service from another centre, you should proceed as follows:

If the aircraft is inbound to your centre, advise the aircraft that no ATC is available, and ask him to call you at some point close to the boundary for example:

EGPX_CTR: AWG4411, NO ATC AVAILABLE AT EISN_CTR REPORT OVER MULLA.

Obviously if the aircraft will conflict with other traffic under your control you may specify a level the aircraft should be at when entering your airspace. If the aircraft is leaving your airspace and entering an unmanned ACC, the following example is suggested:

EGPX_CTR: UKD14, NO ATC AVAILABLE AT EISN_CTR, RADAR SERVICE TERMINATED, CONTINUE ON UNICOM 122.80.

En-route Navigational Assistance to Inexperienced Pilots

If a pilot insists on you navigating for him, other than suggesting the use of the built-in Flight Sim GPS, there is little choice but to spell out a route of flight. This can be distracting and time consuming. The most practical solution, other traffic permitting, is to provide as few VORs as you deem reasonable and assign a heading to fly until receiving the next VOR.

Tips for coordinating in chat box windows

Make sure you have a distinctive sound associated with "chat message" under Options/Sounds menu. When coordinating with another controller it is always better to suggest a course of action to resolve a situation rather than ask the other controller what he wants to do about it.

Summary

The most important thing to remember is to have fun. No one is perfect. Utilize your time online to hone your skills. You will find that even if you are unsure about a particular procedure or instruction, most pilots will gladly help and return often knowing that they are working with a cool, level-headed controller who can adapt to changes. Flexibility is the key. Not all things will work the way you want for various reasons, but having a plan and being flexible will keep all parties calm and happy.

Final Advice

Please remember that this is a simulation. Leave your anxiety and temper at the door and try and act as professional and pleasant as possible. You will always come across pilots and other controllers that you would love to vector into the ground, but do your best to overcome any aggression.

Also, keep your head in the game! Things could get hectic and you have to be ready. More mistakes are made by controllers during slow periods because they forget that it only takes one aircraft to ruin your day. Pay attention and learn from other people's experiences.

Oh Yes - a Warning

.....Its very very very enjoyable and addictive!!!