GMC SOP – Procedures
Basic Procedures
Selection of Runway-in-use
The duty of selecting the runway-in-use is a joint responsibility of Rīga Tower and Rīga Approach. Should both of those stations be offline, the responsibility is transferred to the highest station online; this includes Rīga Ground, should it be the only station online.
The main method of determining the runway-in-use is based on surface wind. The current METAR always contains that information in the following format: 35011KT
. This contains the direction of the wind (350 degrees in this case) and its speed (11 knots). If the wind direction is closer to 360 degrees (from 270 degrees to 089 degrees), runway 36 shall be selected; otherwise, if the wind direction is closer to 180 degrees (from 090 degrees to 269 degrees), runway 18 shall be selected.
The following factors can be also taken into consideration when selecting the runway in use:
- approach and landing facilities serviceability;
- meteorological conditions (RVR);
- reported or forecast wind shear, or when thunderstorms are expected to affect the approach or departure;
- air traffic flow/direction;
- preferential runway system.
A runway-in-use direction with a tail wind component, including gusts, not exceeding 5 kt can be assigned, when:
- air traffic flow expected to runway direction;
- the crosswind component, including gusts, does not exceed 15 kt and/or;
- the runway condition is not worse than “WET” and braking action is not worse than “GOOD” and;
- braking action is not adversely affected by runway contaminants such as ice, slush, snow, frost and water.
The preferential runway system is applied as follows (time given in Rīga local timezone):
00:00 to 17:59 | 18:00 to 23:59 | |
---|---|---|
TAKE OFF | 18/36 | 18/36 |
LANDING | 18/36 | 36 |
Assignment of SSR (Squawk) Codes
All aircraft must be assigned a valid SSR code. In Riga FIR, the following squawk ranges apply:
- 4300 – 4377 for all international flights;
- 0060 – 0077 for all domestic flights (including domestic VFR).
Flight Plan Validation
All aircraft receiving a departure clearance must have a valid flight plan filed (with an exception for VFR flights as long as their intentions are clearly communicated).
Regardless of the presence of a flight plan or lack thereof all aircraft must have a callsign associated with them and their type must be known.
A flight plan is valid if all of the following conditions are met:
- The route starts with one of the waypoints that a SID leads to.
- The route has a Coordination Point Exit (COPX) with one of the FIRs that neighbour the Riga FIR.
- The route has COPX points on all FIR borders that it passes through.
- The Requested Flight Level (RFL) is appropriate for the direction of flight.
The determination whether the RFL is appropriate for the direction of flight is made using the semicircular rule.
- EASTBOUND flights must fly on ODD flight levels.
- WESTBOUND flights must fly on EVEN flight levels.
Designation of odd and even flight levels is sequential up until FL410, thus such FLs as 210, 230, 330, 350, 370, etc. are odd and FLs 220, 280, 320, 340, 360, etc. are even. FL410, however, is the upper limit of RVSM airspace, after which the designation of flight levels happens only every other level, i.e. FL430 is even, FL450 is odd, etc. After FL510, the designation becomes limited to only every 4 levels, therefore, after FL510, the next level is FL550.
Departure Clearances (IFR)
A departure clearance is the initial clearance an IFR flight receives on first contact with ATC. For the departure clearance to be issued all of the following conditions must be true.
- The pilot must have filed a valid flight plan.
- The requested flight level in the flight plan must be valid for the planned direction of flight.
- The pilot must be aware of the current weather conditions at their departure airport. Awareness of said conditions is determined based on the knowledge of the current ATIS identification letter and local QNH by the pilot.
- The ATCO issuing the clearance must be aware of the aircraft’s location and type.
Contents of an IFR Departure Clearance
A departure clearance must contain all of the following items in the order given.
- Standard Instrument Departure.
- SSR code.
Should the pilot be unable to execute the issued clearance or the pilot’s request be that not requiring a Standard Instrument Departure, further departure instruction shall be appended to the end of the departure clearance.
Specifics of RIX Riga Airport
The following rules apply when issuing an IFR departure clearance out of RIX Riga Airport.
- Runways 36 and 18 use H and F SIDs respectively by default.
- J SIDs are available for runway 36 on request; EVRA APS must be notified should a J SID be issued.
- All non-standard clearances must be requested for release from (i.e. coordinated with) relevant ATS units.
DCL/PDC
IFR departure clearances may be issued by datalink. All items of a datalink clearance must be thoroughly checked by the issuing ATCO. A short instruction on the use of the datalink is available in the EuroScope Plugins Guide.
Pushback and Start-up
A pushback and start-up clearance is needed to authorise initial movement on the apron for a given aircraft and to allow for them to begin maneuvering/taxiing towards the runway-in-use. Such a clearance may only be issued once the aircraft in question has matched their SSR code to the one assigned in the departure clearance.
Pushback clearances in EVRR FIR are issued WITHOUT a direction provided.
There are cases when pushback might not be required for a given aircraft. At Rīga the following stands do not require pushback.
- 100
- 101
- 103
- 108
- 109
- 204 (for aircraft not larger than DH8D)
- 208 (for aircraft not larger than DH8D)
- 224 (for aircraft not larger than DH8D)
- 226
- 290 – 292 (LIGHT aircraft only)
- 309
- 311 – 317
- 461 – 462 (LIGHT aircraft only)
- 471 – 479 (LIGHT aircraft only)
The following stands require a straight pushback due to their proximity to the terminal and other airport infrastructure.
- 102
- 105
- 300
- 303
Aircraft parked on the following stands are required/recommended to be pushed back onto taxiway W:
- 302 (mandatory)
- 304, 306 (optional)
An exhaustive table describing stand characteristics and limits is available in the Republic of Latvia AIP chart EVRA AD 2.24.2 on page 2.
Ground Movement
Any movement happening on the ground of a controlled airfield falls under the rules outlined in this section with some overlaps and exceptions for uncontrolled airfields. Control over ground movements is facilitated through the use of taxi clearances and modifying instructions (incl. conditions, give-way instructions, holding instructions, etc.). Generally, all taxi clearances should include the following items:
- the destination at which the aircraft is expected to hold position;
- the optimal taxi route;
- any relevant modifying instructions.
The designated destination of a taxi route can be a holding point (both named and unnamed, i.e. runway holding points), a parking stand, or a de-icing pad. The optimal taxi route is usually, but not always the shortest possible route to the designated destination. Deviations from this may be allowed for sequencing purposes and to apply priority rules.
All taxi routes must not include the taxiway the aircraft is currently located on unless it is standing on taxiway F.
Taxiing aircraft shall observe the ground speed limit of 30 knots.
Departure Taxi Routes
Departing aircraft should be directed to taxi to one of the holding points adjacent to the runway-in-use. The default holding points are reachable via taxiway A for runway 36 and via taxiway G for runway 18, however, other intersections may be offered to pilots in non-LVP conditions. Below is a table of runway intersections available at Rīga.
Runway | Intersection | TORA/TODA (m) | Remarks |
---|---|---|---|
18 | G | 3200 | Full length |
18 | E | 2609 | Should be offered to all departures with WTC L/M |
36 | A | 3200 | Full length |
36 | B | 2509 | Should be offered to all departures with WTC L/M |
36 | C | 2002 | May be offered to departures with WTC L/M |
36 | K | 2003 | Only available from the western side of the airport (apron Z3) |
TWY Y and TWY D are designated as rapid exit taxiways (RETs) and must not be used for departing traffic as they have no published TODA/TORA values. Additionally, roads on the west side of the airport do not have taxilines on them and therefore cannot be used as taxiways or departure runway intersections.
Although use of the intersections is not limited by wingspan or MTOW, it is fairly uncommon for WTC H traffic to use any intersection other than A or G, therefore pilots of such aircraft need not to be explicitly offered intersection departure opportunities to prevent unnecessary frequency congestion.
De-icing Procedures
Should de-icing be required due to weather conditions, any aircraft requesting such services shall be provided with requested de-icing fluid at an appropriate apron/designated position. Republic of Latvia AIP EVRA AD 2.20.9.1 stipulates the following rules for determining the appropriate de-icing position:
Aircraft de-icing shall be carried out in areas specifically designated by the airport. Jet airplanes with engines mounted under the wing and propeller type aircraft will normally be de-iced on remote de-icing pads with running engines. Aircraft with tail mounted engines which during tactile check have been found to have “clear ice” de-icing shall be carried out on apron with engines off.
Aircraft carrying out de-icing on an apron position are expected to notify GMC appropriately, though no assistance is expected from the GMC ATCO. An apron position may either be a parking stand or the aircraft’s position after pushback only with engines off. Aircraft requiring the use of a de-icing pad are expected to request taxi instructions appropriately from GMC.
At Rīga there are 8 de-icing pads placed symmetrically next to the runway. De-icing pads adjacent to runway 36 are designated as DS1 through DS4 while those adjacent to runway 18 are designated as DN1 through DN4. Although there are no set rules for the use of each de-icing pad, below is a table explaining the generally understood way of assigning de-icing pads to requesting aircraft.
De-icing Pad | Limits | Remarks |
---|---|---|
DS4, DN4 | Max. wingspan 36 m | Primary de-icing pads |
DS1, DN1 | Max. wingspan 36 m | Secondary de-icing pads |
DS3, DN3 | Not suited for B748, A388, and similarly sized aircraft | NIL |
DS2, DN2 | NIL | To be used for B748, A388, and similarly sized aircraft |
Arrival Taxi Routes
Arriving aircraft should be directed to taxi to a designated stand. In most cases the optimal taxi route matches the shortest possible route barring any safety concerns and application of priority rules. Below is a non-exhaustive table describing stand allocation rules at Rīga.
Stand | Origin Filter (Schengen*) | Limits | Remarks |
---|---|---|---|
100 | NIL | Max. wingspan 65 m | Frequently used for heavy aircraft; blocks stands 112 through 115 |
101 | Schengen ONLY | Max. wingspan 29 m | NIL |
103 | Schengen ONLY | Max. wingspan 30 m | NIL |
102, 104 – 109 | Schengen ONLY | Max. wingspan 36 m | NIL |
110, 111 | NIL | Max. wingspan 36 m | Stand next to the VIP terminal |
112, 113 | NIL | Max. wingspan 36 m | Block stand 100, and stands 112 through 115 |
114 | NIL | Max. wingspan 52 m | Blocks stand 100, and stands 112 through 115 |
115 | NIL | Max. wingspan 42 m | Blocks stand 100, and stands 112 through 115 |
204, 206 | NIL | Max. wingspan 27,05 m | NIL |
205, 207, 208 | NIL | Max. wingspan 35,92 m | NIL |
214 – 218 | NIL | Max. wingspan 36 m | NIL |
219 | NIL | Max. wingspan 35 m | Very seldom used for non-BTI aircraft |
224 | NIL | Max. wingspan 35,9 m | NIL |
225 | NIL | Max. wingspan 36 m | NIL |
226 | NIL | Max. wingspan 36 m (see remarks) | Contrary to designated max. wingspan was used for A225 in the past |
227, 228 | NIL | Max. wingspan 36 m | NIL |
229 | NIL | Max. wingspan 28,91 m | Is sometimes used for helicopter storage |
230 | NIL | Max. wingspan 28,5 m | Is sometimes used for helicopter storage |
290 | NIL | Max. wingspan 36 m | FBO stand; blocks stands 292 and 293 |
291 | NIL | Max. wingspan 23,8 m | FBO stand |
292, 293 | NIL | Max. wingspan 30,4 m | FBO stand; blocks stands 290 |
300 | NIL | Max. wingspan 65 m | Aircraft must taxi into the stand via TWY U1 |
301 | Non-Schengen ONLY | Max. wingspan 65 m | Aircraft must taxi into the stand via TWY U1 |
302 – 306 | NIL | Max. wingspan 36 m | NIL |
307 – 309 | Non-Schengen ONLY | Max. wingspan 36 m | NIL |
311 – 316 | NIL | Max. wingspan 36 m | NIL |
317 | NIL | Max. wingspan 32 m | NIL |
321 – 326 | NIL | Max. wingspan 36 m | NIL |
327 | NIL | Max. wingspan 34 m | NIL |
401, 402 | NIL | Max. wingspan 42 m | Is sometimes used for aircraft storage |
461 | NIL | Max. wingspan 24 m | GA stand |
462 | NIL | Max. wingspan 28,65 m | GA stand |
467 – 470 | NIL | Max. wingspan 36 m | NIL |
471 | NIL | Max. wingspan 20 m | GA and helicopter stand |
472 | NIL | Max. wingspan 23,93 m | GA and helicopter stand |
473, 474 | NIL | Max. wingspan 22 m | GA and helicopter stand |
475 | NIL | Max. wingspan 22 m | GA stand |
476 | NIL | Max. wingspan 23,93 m | GA stand |
477 | NIL | Max. wingspan 22,75 m | GA stand |
478 | NIL | Max. wingspan 23,25 m | GA stand |
479 | NIL | Max. wingspan 22 m | GA stand |
501 | NIL | Max. wingspan 73,3 m | Cargo stand, apron 5 (DHL) |
502, 503 | NIL | Max. wingspan 68,4 m | Cargo stand, apron 5 (DHL) |
511, 512 | NIL | Max. wingspan 36 m | Cargo stand, apron 5 (DHL) |
Apron Z3 | NIL | Max. wingspan 42,36 m | Located on the west side of the airfield outside of GMC AoR; engine run-up and test stand |
* The Republic of Latvia is a party to the Schengen agreement that allows for unrestricted movement of people and goods between 29 countries which are parties to the agreement. Further reading is available on The European Commission website and on Wikipedia.
An exhaustive table describing stand characteristics and limits is available in the Republic of Latvia AIP chart EVRA AD 2.24.2 on page 2.
Transfer of Control and Communications
Rīga Ground, the only GMC ATS unit in EVRR FIR, is a non-radar station, therefore the transfer of control and transfer of communications from/to adjacent ATS units happens simultaneously. The only adjacent ATS unit to Rīga Ground is Rīga Tower.
Departures
Departing traffic should be transferred to the next ATS unit while taxiing to the runway-in-use at a sufficient distance from the holding point to ensure continuous movement past the holding point given a situation with no other traffic playing a factor. Executing a transfer just before the departing aircraft leaves taxiway F to join their planned runway intersection generally creates sufficient space to allow for continuous movement of traffic.
Arrivals
Arriving traffic shall switch to GMC frequency unless otherwise stated by TWR upon vacating the runway. All arriving traffic is expected to make the first call on the frequency to begin 2-way communications.
Coordination
Coordination is an inalienable part of air traffic control. Timely and efficient coordinations ensures that all ATS units support each other and facilitate efficient operations at all times. Broadly all coordination between ATS units may be divided into 2 categories: notifications and requests for release.
Notifications
Notifications are designed to notify a neighbouring ATS unit of a condition that may impact their operations that is either unavoidable or for which the responsibility falls onto another ATS unit, or in case said impact is under most circumstances minimal. The receiving ATS unit maintains the right to refuse an incoming notification and request that adherence to standard procedures be resumed, though such refusal must be accompanied by a valid operational reason. Below is a table of required notifications from GMC to neighbouring ATS units.
Recipient | Condition | Remarks |
---|---|---|
APS | A departing IFR aircraft is requesting a J SID | Only when runway-in-use is 36 |
TWR | Long-term unavailability of a taxiway | Reason must be communicated |
TWR | Unavailability of a runway intersection | Reason must be communicated |
TWR | A departing aircraft is to occupy a de-icing pad | NIL |
Requests for Release
Unlike notifications requests for release require immediate action or some form of response from the receiving ATS unit. The receiving ATS unit maintains the right to refuse an incoming request for release as long as the refusal does not constitute a denial of service to any aircraft; such refusal must also be accompanied by a valid operational reason. Below is a table of required requests for release from GMC to neighbouring ATS units.
Recipient | Condition | Expected Response | Remarks |
---|---|---|---|
TWR | A non-IFR aircraft is requesting a departure clearance | A relevant departure clearance | The aircraft remains on GMC frequency and GMC ATCO shall relay the clearance issued by TWR |
APS | An IFR aircraft is requesting a non-standard departure clearance | A relevant departure clearance | The aircraft remains on GMC frequency and GMC ATCO shall relay the clearance issued by APS |
APS | An IFR aircraft is unable to follow a standard departure clearance | A relevant departure clearance and/or instructions to mitigate the possible implications of the reported deviation from standard procedures | NIL |
TWR, APS | An aircraft is requesting to depart from a runway other than the current runway-in-use | Approval/Refusal of the request and any additional relevant instructions | NIL |
Advanced Procedures
Departure Clearances (VFR)
Similarly to IFR aircraft, a departure clearance is the initial clearance a VFR flight receives. In EVRR FIR all departure clearances, including those for non-IFR traffic are issued while the traffic is still at its parking stand.
For the departure clearance to be issued all of the following conditions must be true.
- The aircraft type must be verbally communicated by the pilot and/or stated in the flight plan.
- The aircraft must be equipped with a mode-A functioning transponder.
- The number of souls on board must be verbally communicated by the pilot and/or stated in flight plan remarks.
- The pilot’s intentions must be verbally communicated. If a VFR flight plan is filed, it must include intentions matching the ones stated by the pilot.
The details of the pilot’s request must be communicated to Rīga TWR as part of a request for release. In response TWR is expected to issue a clearance to be communicated to the pilot by GMC. Any changes to the issued clearance must be coordinated with and approved by Rīga TWR.
Contents of a VFR Departure Clearance
A departure clearance must contain all of the following items in the given order.
- Departure instructions.
- Departure runway.
- Altitude restriction.
- SSR code.
Rules for Issuing Departure Instructions
Although the responsibility to issue non-IFR clearances does not lie with GMC, the following section is copied from the TWR SOP – Procedures to accommodate for situations in which GMC is the only ATS unit online which can happen on the VATSIM Network.
VFR operations may only be conducted if the cloud ceiling is at or above 1500FT and RVR is ≥ 4000 meters.
VFR departures may be initially cleared for 2 types of departure: aerodrome visual circuit or a directional VFR departure.
Aerodrome Visual Circuit
The diagram above describes the vertical and lateral limits for the aerodrome visual circuit at Rīga. Should a pilot request to follow a visual circuit as part of their departure clearance request, the following departure instructions shall be issued by default:
EASTBOUND
aerodrome visual circuit (left-hand circuit for RWY 18 and right-hand circuit for RWY 36).- Altitude restriction
NOT BELOW 1500FT
.
Should there be operational reasons (e.g. traffic flow) that impact the safety or practicality of assigning the aforementioned departure instructions, deviations from the default instructions are possible. Similarly, pilots’ requests for non-standard departure instructions may be accommodated within reason.
The altitude restriction within an aerodrome visual circuit MUST NOT exceed 2500FT.
The distance between an aircraft in the aerodrome visual circuit and the runway centerline MUST NOT exceed 3 NM while on downwind (flying parallel to the runway centerline).
Directional VFR Departure
Alternatively to following an aerodrome visual circuit, a pilot may request depart the airfield. A departure request must always contain the requested direction and/or requested exit point (VRP). Should a pilot request to depart the airfield, the following departure instructions shall be issued by default:
- Clearance to exit the controlled airspace including instructions on how the exit shall be performed. Said instructions must contain a valid exit point in the form of a VRP.
- Altitude restriction
AT OR BELOW 1500FT
, unless exiting via SARPS, in that case altitude restrictionAT 1000FT
shall be used.
VFR traffic shall cross Riga CTR boundary via the following CTR entry/exit points: ARNIS, ELING, KROGS. VFR traffic heading towards Spilve ATZ may use exit point SAPRS (at 1000 ft). VFR traffic arriving from Spilve ATZ may use entry points SARPS (at 1000ft) and RIVER (at 500ft).
Should there be operational reasons (e.g. traffic flow) that impact the safety or practicality of assigning the aforementioned departure instructions, deviations from the default instructions are possible. Those deviations include, but are not limited to issuing a clearance for an exit point other than the one that was requested, modifying the default altitude restriction, etc. Pilots’ requests shall be accommodated within the bounds of operational safety and reason.
The altitude restriction for exiting the controlled airspace MUST NOT exceed 1500FT.
Conditional Clearances and Give Way Instructions
There are situations in which a clearance/instruction should be issued to a pilot, but there is some sort of temporary obstacle to the fulfilment of the clearance/instruction in question. In such cases conditional clearances come to rescue. Conditional clearances only differ from regular radio transmissions by them being prepended with a relevant condition. Conditional clearances are composed as follows:
- Conditional keyword [
after
/once (clear of)
]. - Description of the obstacle (i.e. airline and aircraft type).
- Condition based on the current movement of the obstacle.
- The clearance itself.
It is important to note that conditional clearances forbid any action until the condition given is resolved, therefore should a taxi instruction be issued as part of a conditional clearance, the aircraft in question will not be allowed to perform any ground movement/maneuvering and the taxi instruction will not go into effect until the condition is resolved.
An alternative to conditional clearances specifically for taxi instructions is given provided by give way instructions. Unlike conditional clearances, give way instructions may be issued on their own or appended to regular taxi instructions. Give way instructions also do not delay the taxi instruction going into effect, they just limit the scope of it and simply instruct the pilot to give way to somebody else. Give way instructions are composed as follows:
- A regular taxi instruction (if applicable).
- The
give way to
key phrase. - Description of the obstacle (i.e. airline and aircraft type).
- Description of the obstacle’s movement.
Helicopter Procedures
Helicopter movement at Rīga is regulated by Republic of Latvia AIP EVRA AD 2.16 and 2.20.10. Helicopters may take off both from the runway and from the helipad (next to stand 230). Special helicopter stands are available at Rīga – H01 and H02. ALL helicopter movement must be coordinated with and released by Rīga Tower. The following rules apply to all helicopters at Rīga:
- Any helicopter vacating the helipad must report “helipad vacated” or be asked to confirm this.
- Helicopters with skid undercarriage are to use all ground taxiways as air taxiways.
- All helicopters intending to air taxi should include the term “air taxi” in the taxi requests. If it is unclear, which type of taxi the pilot is requesting they shall be prompted to specify it.
- Wheeled helicopters shall not use helicopter stands for turning on the ground and may ground taxi for departure when pre-aligned on the respective lead-out line. Wheeled helicopters shall not touch down or lift off on aircraft stands 313, 314, 315, and 316.
- Helicopters landing on the helipad shall avoid, as far as practicable, overflying any other aircraft, de-icing pads, and all aprons except Apron 2. It is a joint duty of Rīga Ground and Rīga Tower to prevent violations of this rule.
- Simultaneous movement on the helipad and H01/H02 stands is NOT allowed.
- Simultaneous movement on the helipad and the runway is NOT allowed.
- Any traffic overflying RIX Riga Airport at or below 1500 ft is considered to be an obstruction to runway movements (this includes both helicopters and fixed-wing aircraft).
Workload Management and Safety
Safety is the top priority of any air traffic service. Pre-planning, consistency, and proper application of priority rules are the backbone of safe and efficient service. This section explains the mentioned concepts one by one.
Pre-planning
The process of pre-planning is crucial to maintaining safe and efficient operations. The process consists of 2 parts:
- Determining the preliminary traffic sequence (i.e. planning the provisional order of aircraft with equal priority).
- Considering the clearances and instructions that should be issued in the next 5 to 10 minutes.
Obviously, deviations from the initial plan are possible and happen quite often in practice, though having a plan beforehand is always much safer than not having one. Finally, it is important to note that planning also requires spacing to be taken into account. As a rule of thumb, all traffic should be prevented from blocking other traffic as much as reasonably practicable, for example, not more than 2 aircraft should be in-waiting at intersection B in order to not block TWY F. Consideration of potential consequences must always be applied when sequencing traffic and issuing instructions!
Consistency
The general recommendation to help maintain consistently efficient operations is to apply the so-called “scan” technique. GMC ATCOs are expected to be on the lookout for the following things when scanning their AoR:
- Departing traffic approaching the holding point (i.e. expected handoffs to TWR).
- Arriving traffic vacating the runway (i.e. incoming handoffs from TWR).
- Traffic following the instructions issued to them.
- Traffic being in the queue for a clearance of any type.
Application of Priority Rules
GMC should apply the following priority rules to traffic within its AoR:
- Transfer of control of departing traffic to TWR is the instruction with the highest priority.
- Departing traffic shall be prioritised over arriving traffic on frequency, arriving traffic should be prioritised over departing traffic in terms of ground movement.
- Aircraft which have started their engines have priority over those that have not done so.
- Traffic following IFR always has priority over traffic following VFR or any other type of flight rule.
Low Visibility Procedures
Low Visibility Procedures shall be applied at Rīga in accordance with Republic of Latvia AIP EVRA AD 2.22.4. The criteria for instantiating and cancelling LVP are as follows:
- Standby for low visibility procedures is prompted by ATC when RVR is 700 m or less or the ceiling is 200 ft or less.
- Low visibility procedures are effected by ATC when RVR is 550 m or less or the ceiling is 150 ft or less.
- Low visibility procedures are cancelled by ATC when RVR is greater than 700 m and a continuing improvement in RVR conditions is anticipated, and the ceiling is greater than 250 ft.
Pilots will be informed when low visibility procedures are in operation by ATIS or radio. Pilots will be informed over radio when LVP are cancelled. Low visibility operations will be suspended as a result of certain equipment failure/degradation modes or procedure breaches. ATC procedures do not allow for snow clearing on the manoeuvring area when LVP are effected but do allow for limited snow clearing on the manoeuvring area when standby for LVP is prompted.
When LVP are effected, the following taxiways may be used to vacate the runway: A, B, C, Y, D, E, and G. Backtrack procedures are NOT allowed unless that is the only safe way to vacate the runway. When LVP are in force runway entries are limited to:
- taxiway A for runway 36 (or taxiway B if A is not available);
- taxiway G for runway 18 (or taxiway E if G is not available).
Only taxiways with centre line lights shall be used for taxiing. A list of such taxiways can be found in the Republic of Latvia AIP EVRA AD 2.24.1 Aerodrome Chart. Otherwise, presence of a “follow me” vehicle is required.
When LVP are in force, all taxiing aircraft shall resort to using Intermediate Holding Positions (IHP) equipped with yellow IHP lights. Such IHP are located on the following positions:
- on taxiway F at intersections with taxiways E, D, C, A, B, de-icing pad DS (south), de-icing pad DN (north), as well as IHP F1 and F2;
- on taxiway G; IHP G1 and G2;
- on taxiway A; IHP A1 and A2;
- on taxiways E, D, C and B: ITHP before intersection with taxiway F.
All aircraft taxiing to the runway-in-use shall be instructed to hold short of one of the IHP on taxiways A or G listed above. (IHP listed for taxiway F at intersections with taxiways B and E may be used when taxiways A and G respectively are unavailable)
Taxiing aircraft shall observe the ground speed limit of 15 knots.
VATSIM Specifics
Although Latvia vACC strives to achieve maximum realism, there are still some specifics introduced by the VATSIM environment that must be taken into account.
Communication Types
VATSIM offers all pilots 3 types of communication. All aircraft in a given ATS unit’s AoR must be provided service on an equal basis, regardless of their type of communication. The available types of communication are explained below:
- VOICE (
/v
or blank space in EuroScope) – the pilot both receives voice instructions and speaks on frequency themselves; - RECEIVE (
/r
in EuroScope) – the pilot receives voice instructions, but speaks on frequency using text; - TEXT (
/t
in EuroScope) – the pilot receives instructions in text and speaks on frequency using text.
It is generally recommended that text (/t
) pilots receive instructions relevant to them a little earlier than other pilots normally would to provide ample time for the pilot to read the instruction back in text form.
Use of Aliases and Commands
A set of basic EuroScope commands is available in the EuroScope Basic Guide. This section will primarily focus on the available aliases.
To better accommodate text (/t
) pilots, the EVRR FIR Sector File has a list of aliases built in. Below is a non-exhaustive list of aliases that are most relevant to GMC:
.clr
– issues an IFR clearance;.rc
– read back correct;.sq
– prompts the aircraft to set the correct squawk code;.ps
– pushback and start-up approved;.su
– start-up approved;.taxi36
or.taxi18
– taxi instructions to the respective runway;.cont
– hands the aircraft off to the next ATS unit; the relevant EuroScope station ID shall be used in the blank spaces, the instruction will populate with relevant values after theTAB
key is pressed;.v?
– asks the aircraft if they’re able to receive voice instructions.
A full list of all aliases built into the EVRR FIR Sector File is available in the respective folder inside the sector file: %sector_file_folder%/EVRR/Alias/alias.txt
.