You are manning a position and all has been going smooth since you came on line. Aircraft are following their routes, filing their flight plans, departing and arriving as directed and you wonder if anything ever gets interesting. Well it does as there are a few not so usual situations that can occur from time to time, especially at the Practical Tests all members have to take and pass for the Controller ratings.We thought it may be interesting and beneficial to cover a number of these situations, in effect members are urged to simulate these on line as part of local VACC training, getting together with a few friendly pilots who are willing to participate. Some of the situations described below can occur in VATSIM others at least at the present time are impossible to recreate, however we hope you enjoy learning a bit about them all.
A go-around, overshoot or missed approach is an aborted landing of an aircraft which is on final approach.
Missed Approach procedures differ from airport to airport and the procedure to be flown can be found on the respective approach plates. In general in VATSIM, ATC usually tends to give all aircraft the same command on a Missed Approach being something similar to:
EX123 Fly runway heading to 3000ft, stand by for vectors.
Whilst one could argue that there really is nothing wrong with this approach to things, as it would allow the pilot to climb on the runway heading giving him or her the time to read the published procedure, the fact is that it is not really correct as there are specific Missed Approach procedures in use at various fields, which call for different instructions.
The Fly Runway heading in VATSIM is being used generally for a number of reasons.
- Easy to remember.
- Gives the ATC flexibility in deciding if the approach will be a left or a right had turn
- Easy for pilots.
However, as most of us know, the increasingly sophisticated Add On packages available means that a growing number of us are able to follow the correct Missed Approach procedure which – you have guessed it – is not a runway heading.
Let us look at the standard phrases and terms that exist in respect to missed approaches, there are more than one may think.
- Missed Approach (MA): Other expression for Missed Approach Segment.
- Missed Approach Point (MAPt): This designates the point during a non-precision instrument approach that signals the termination of the final approach and the start of the missed approach segment, this point may be:
- The intersection of an electronic glide path with a decision height.
- A NAVAID located at the field
- A suitable fix, for example a DME
- · A specified distance beyond the NAVAID or final approach fix, (FAF), not to be exceeded.
- Missed Approach Holding Waypoint (MAHWP) the waypoint designated in the missed approach segment of an instrument approach procedure to which the aircraft will automatically fly and upon reaching this position, enter a specified holding pattern.
- Missed Approach procedure: The procedure that has to be followed after an instrument approach procedure, if, for any reason, a landing can not be effected. It normally occurs:
- When the Aircraft has descended to the decision height (DH) or to the minimum descent altitude (MDA) and reached the missed approach point or waypoint and has not established the required visual reference to land.
- When the aircraft is directed by ATC to pull up or to Go Around.
- Missed Approach Segment: The Part of an instrument approach procedure between the missed approach point, (MAPt), the missed approach waypoint (MAWP) or the point of arrival at Decision Height, and the specified missed approach NAVAID, intersection, fix or waypoint, as appropriate, at the minimum IFR altitude. It is in this part of the approach procedure that the aircraft climbs and returns to the en-route structure or is directed for holding or subsequent approach.
- The route of flight and altitudes are shown on instrument approach charts.
- Missed Approach Turning Waypoint: (MATWP) The waypoint designated in the missed approach segment of an instrument approach procedure to which the aircraft will automatically fly en route to the specified missed approach holding waypoint. (MAHWP)
- Missed Approach Waypoint (MAWP) The waypoint on the final approach course that signifies the termination of the final approach segment and the start of the missed approach segment.
- Overshoot: The phase of a flight wherein a landing approach of an aircraft is not continued to touchdown (also called Go-Around)
- Decision height (DH) is a specified height in the precision approach at which a missed approach must be initiated if the required visual reference to continue the approach has not been acquired. This altitude specified gives the pilot sufficient time to safely re- configure the aircraft to climb and execute the missed approach procedures while remaining clear of terrain and obstacles.
The go-around procedure may be initiated either by ATC or by the captain of the aircraft.
The air traffic controller will instruct the pilot to go around if there is an aircraft, vehicle or object on the runway or there are other hazards that could bring the aircraft into a dangerous situation unless instructed to go around. The captain will decide to go around if the aircraft is not lined up or configured properly for the approach, a landing aircraft has not cleared the runway, no landing clearance was issued, the runway is not visible by the time the aircraft reaches the decision height because of low visibility, or if other dangerous meteorological conditions are experienced on final approach.
A go-around in itself does not constitute any sort of emergency.
In other words:
An aircraft shall be instructed by ATC to carry out a missed approach in any of the following cases:
- On Instructions from TWR ATC if no landing clearance is received at the MAWP or DH
- On Instructions from TWR ATC if the aircraft appears to be wrongly positioned on final approach.
- On Instructions from TWR ATC if the aircraft is not visible on radar during final approach.
- On instructions from TWR ATC if the landing runway is not cleared by other aircraft’s.
A pilot can initiate a Go Around on his own if:
- The pilot arrives at DH and is still in the clouds and does not have any visual references
- The pilot has not received Landing Clearance at the DH in this situation actually the pilot HAS to go around except if the pilot decides that going around would bring the aircraft into a more dangerous situation than landing (for example if low on fuel)
- The pilot deems that to continue the approach would endanger the aircraft.
When the captain is instructed, or decides himself to go around, he will apply full power to the engines, adopt an appropriate climb attitude and airspeed, retract landing gear, retract flaps as necessary and follow the published missed approach procedure (a set path to follow in the event of a go-around) or the instructions of the air traffic controller.
A common mistake, which again and again is heard by ATC from different countries instructing an aircraft executing a missed approach, is the following command:
EX123 climb to 3000ft on runway heading.
This is wrong; there is no need to tell the pilot to climb! The pilot is already climbing as per the prescribed Missed Approach Procedures.
The correct command should be something like this
EX123 execute missed approach for runway xx
EX123 continue missed approach, stand by for vectors.
However many pilots on VATSIM are not prepared for a possible missed approach and do know the missed approach procedures. ATC should ask the pilot whether he is able to follow standard missed approach. If he does not then vectors similar to the example above are given.
Choose any local approach chart from your VACC and get familiar with the missed approach procedures. The example below illustrates a simple missed approach procedure and the impact this may have on ATC.
Runway 27: The aircraft continues on a track of 267° to 3000ft and upon reaching 3000 feet (more or less 2nm from GE) the pilot would turn right toward the LO NDB on 314 and would enter the prescribed hold at LO.
The above procedure should happen automatically and unless ATC gives a different command.
As you can imagine we do not want an aircraft circling at 3000ft over LO for too long, especially if there is more traffic inbound the field. So, prior to the aircraft arriving at LO, you could instruct the aircraft to leave LO on heading 110 for a left hand procedural approach back to runway 27.
EX123, going around
Twr “somewhere” Copy Exair123 execute missed approach rwy 27, report inbound LO
EX123, inbound LO
Twr “somewhere” Exair123 leave LO on Heading 110, maintain 3000ft vectors for LOC runway 27
From there onwards it is only a matter of vectoring to bring the aircraft back to the LOC as usual.
Different Fields use different procedures and these procedures again are different depending on the type of aircraft involved in the process. The main thing to bear in mind is that the missed approach procedure does involve a prescribed hold unless ATC instructs the pilot differently.
There are two main methods to control traffic: Radar and Non-Radar.
Radar is used to accurately determine each aircraft’s position in order to separate and sequence traffic.
Non-radar uses time and distance to create blocks of protected airspace for each aircraft along its route.
In real-life, both methods are normally used together according to the situation and equipment limitations, as Radar coverage may not always be 100%. Especially over the ocean or in remote areas.
Procedural Approaches are normally used in NON RADAR environment; hence they will hardly (if ever) be of importance for us as VATSIM is a 100% radar environment.
However, having said this, we can if we so want to; simulate a Non Radar environment. Such a simulation may in fact be simulated during a Controller Practical Test
In earlier versions of the software we use it was possible for a pilot to disconnect from the servers whilst maintaining voice contact as the programs used were stand alone applications. With voice now being integrated the moment a pilot disconnects he or she is totally gone. The only way to simulate a loss of radar contact is:
- For the pilot to disconnect but keep a pre agreed kind of voice communication open, for example team speak or Skype
- For the pilot to change his Squawk from C mode to Standby mode, as ATC you will lose all the vital data. Depending on radar mode used you may see an “x”.
- For you as ATC to turn off the monitor, the problem here would be that all traffic in your area is blanked out.
In practice (if this situation should occur) then the most likely scenario will be the pilots continuing on line but in Standby mode.
Assuming however that a non radar or radar loss occurs then you as ATC will have to reply mainly on the pilot being able to maintain non-radar separation minima: which is the minimum (visual) separation to be maintained by approaching aircraft following a published procedure approach.
APP Somewhere, ExAir123 lost radar contact, do you copy on voice?
ExAir123, Approach affirmative
APP Somewhere, ExAir123 report speed, heading and FL
ExAir123 speed 310, heading 180, FL120
APP Somewhere, ExAir123,depart SVD on R-210, descend FL80, speed 250kias
ExAir123, copy SVD on R-210, FL80 and speed 250kias
APP Somewhere, ExAir123 report DME 20 SVD VOR on R-210
ExAir 123, reporting at D20 SVD on 210
APP Somewhere, ExAir123 descend FL60, maintain present heading report abeam KAS VOR
ExAir123 copy FL60, hdg 210 will report abeam KAS
ExAir123 reporting abeam KAS
APP Somewhere, ExAir123 copy, turn left heading 175 for vectors ILS APP runway 04L, report over EKRK or RK NDB
ExAir123, left hdg 175 for 04L will report over EKRK or RK NDB
ExAir123 reporting over EKRK, (or RK NDB) FL60
APP Somewhere, ExAir123 descend to 4500ft on QNH 1013 report D15 KAS on radial 075
ExAir123 at D15 on R-075 KAS
APP Somewhere, ExAir123 turn left for base hdg 130 descend to 2500ft, reduce speed to 190kias
ExAir123, 2500ft, 190kias on base leg
APP Somewhere, ExAir123 turn left hdg 070 cleared ILSapp 04L please log back on SB now or Squawk C mode now
We should not ever use these procedures unless approved as part of a Practical test or upon request from a pilot wanting to test his flying skills making use of his IFR instruments or on request of an ATC wanting to gain more “spatial” knowledge.
Having trained this kind of situation ATC hopefully have learned how to anticipate in their mind where an aircraft is in relation to other aircraft and in relation to the Airport and active runway.
In VATSIM, our environment, it is impossible to have a communication loss as we have redundancy since we can use both Voice and Text. In real life though a 7600 squawk signifies No Radio or Lost Verbal Communication.
This code lets controllers know that a radio failure has occurred on the plane. Planes with a radio failure are given priority over other, non- emergency traffic, and as long as the pilot has visual contact with the airfield, then ATC will communicate with them via aviation light signals..
Neither Flight Simulator nor our on line programs are capable of mimicking the use of aviation light signals so this will never occur at the present time in VATSIM but assuming it could:
In the case of a radio failure or aircraft not equipped with a radio, air traffic control may use a light gun to direct the aircraft. The light gun has a focused bright beam and is capable of emitting three different colors: Red, white and green. These colors may be flashed or steady, and have different meanings to aircraft in flight or on the ground. Planes can acknowledge the instruction by wiggling their wings, moving the ailerons if on the ground, or by flashing their landing or navigation lights during hours of darkness.
Aircraft In Flight
Aircraft On the Ground
Ground Vehicles or Personnel
Return to engine start-up point
Cleared to land
Cleared for takeoff
Cleared to cross/proceed
cleared to approach airport, or return to land
Cleared to taxi
Continue circling, give way to other aircraft
Airport unsafe, do not land
Immediately taxi clear of runway in use
Clear the taxiway/runway
Alternating Red and Green
Danger, continue current action with caution
Nearing restricted airspace
Blinking Runway Lights
vehicles, planes, and pedestrians immediately clear landing area in use
In the event a “simulated” radio communication failure should occur, you as ATC will be able to track the aircraft and vector possible conflicting traffic away from the stricken aircraft which in the absence of instructions will follow a procedure similar to lost radar contact.
Instrument approaches are generally designed such that a pilot of an aircraft in instrument meteorological conditions (IMC), by the means of navigation with no assistance from air traffic control, can navigate to the airport, hold in the vicinity of the airport if required, then fly to a position from where he or she can obtain sufficient visual reference of the runway for a safe landing to be made, or execute a missed approach if the visibility is below the minimums required to execute a safe landing. The whole of the approach is defined and published in this way so that aircraft can land if they suffer from radio failure; it also allows instrument approaches to be made procedurally at airports where air traffic control does not use radar or in the case of radar failure.
- PROCEDURE: A recommended or optional directive or a mode of operation.
- PROCEDURE TURN: A maneuver in which a turn is made away from a designated track followed by a turn in the opposite direction, both turns being executed so as to permit the aircraft to intercept and proceed along the reciprocal of the designated track. Procedure turns are designated "left" or "right" according to the direction of the initial turn. However, if possible, the procedure turn is designated "left." (also called a “teardrop”)
- SEPARATION MINIMA: Minimum (visual) separation to be maintained by approaching aircraft following a published procedure approach.
As ATC you will not have any further involvement with this aircraft and your job is limited to ensuring that all other aircraft in the area are advised that there is an aircraft in distress in the vicinity and that they may expect vectors or holds or delays due to the present situation.
ATC will ensure that the airspace and the primary landing runway are kept free of any conflicting traffic to ease the approach of the aircraft in question simulating 7600.
Code 7600 is frowned upon in VATSIM, as it is not realistic in our simulated environment. As such unless this was pre-arranged and part of a practical test as ATC you should call for supervisor assistance and in the absence of any supervisor on line you should file an incident report.
Ending this series of the “unexpected” we focus on Emergencies.
An emergency condition is classified in accordance with the degree of danger or hazard present.
(a) Distress is a situation where safety is being threatened by grave and imminent danger and requires immediate assistance. The spoken word for distress is MAYDAY and is pronounced 3 times.
(b) Urgency is a situation where the safety of an aircraft or other vehicle or of some person on board or within sight is threatened, but does not require immediate assistance. The spoken word for urgency is PAN PAN, and is pronounced 3 times.
The first transmission of the distress call and message by an aircraft should be on the air-to-ground frequency in use at the time. If the aircraft is unable to establish communication on the frequency in use, the distress call and message should be repeated on the general calling and distress frequency 121.500 MHz, or any other frequency available, in an effort to establish communications with any ground or other aircraft station.
The distress call shall have absolute priority over all other transmissions. All stations hearing it shall immediately cease any transmission which may interfere with it and shall listen on the frequency used for the distress call.
MAYDAY, MAYDAY, MAYDAY, THIS IS EX123, FIVE ZERO MILES SOUTH OF BUDAPEST AT ONE SEVEN TWO FIVE ZULU, FLIGHT LEVEL TWO HUNDRED, AIRBUS 320, OUT OF FUEL, WILL ATTEMPT CRASH LANDING AT LHBP, EX123 OVER
PAN PAN,PAN PAN, PAN PAN, ALL STATIONS, ALL STATIONS, ALL STATIONS, THIS IS BORDEAUX APPROACH, REPEAT THIS IS BORDEAUX APPROACH, EMERGENCY DESCENT AT BORDEAUX AIRPORT, ATC INSTRUCTS ALL AIRCRAFT BELOW FLIGHT LEVEL 70 WITHIN RADIUS OF ONE FIVE MILES OF “XYZ” VOR LEAVE WEST AND NORTH COURSES IMMEDIATELY, THIS IS BORDEAUX APPROACH OUT.
(a) The following general procedures are intended as guidance only. Although all possible contingencies cannot be covered, they provide for cases of inability to maintain assigned level due to:
(ii) Aircraft performance; and
(iii) Pressurization failure.
The pilot’s judgment shall determine the sequence of actions to be taken, taking into account specific circumstances, and ATC shall render all possible assistance.
(b) If an aircraft is unable to continue flight in accordance with its ATC clearance, a revised clearance shall, whenever possible, be obtained prior to initiating any action, using a distress or urgency signal if appropriate. If prior clearance cannot be obtained, an ATC clearance shall be obtained at the earliest possible time. The pilot should take the following actions until a revised ATC clearance is received:
(i) Establish communications with and alert nearby aircraft by broadcasting, at suitable intervals: flight identification, flight level, aircraft position, (including the ATS route designator or the track code) and intentions on the frequency in use.
(ii) Initiate such action as necessary to ensure safety. If the pilot determines that there is another aircraft at or near the same flight level, which might conflict, the pilot is expected to adjust the path of the aircraft, as necessary, to avoid conflict.
This is the most serious of the 3 codes, as it signals that the aircraft is either in distress or in an unsafe condition requiring urgent action from both ATC as pilot.
The first thing to do is to react on the “Mayday” (Distress) or “Pan-Pan” (Serious Emergency) messages broadcast by the pilot.
- Acknowledge receipt of Emergency
- Inquire as to the nature of the Emergency
- Inquire as to the number of souls (persons) on board
- Inquire as to the fuel on board, in terms of minutes of flight time.
- Let the PIC state his intentions or request.
ExAir123, Mayday received, when able Advise Nature of Emergency, Pax and Fuel on board and Intentions.
Remember that the pilot has a lot to do in trying to control an unresponsive aircraft and he may not be in a position to give you an immediate answer, don’t get upset or press for a reply.
Assist the pilot as best as you can, ensure that ALL traffic in the area is well clear of the code 7700 aircraft both horizontally and laterally. If it looks like the code 7700 is approaching an airfield in order to attempt a landing, ensure the approach to and the runway is free of conflicting traffic.
If you have other inbound IFR or VFR traffic, vector them around and away from the Code 7700 aircraft.
A 7700 code takes precedence over ALL other traffic, ATC need to give this code 7700 its utmost time and attention without forgetting all other traffic under its area of control.
If you encounter a 7700 on route requesting deviation to a nearest airfield which happens to lie outside of your FIR, advise pilot that nearest airfield is ABC at XX nautical miles in the ABC FIR. Or nearest local Field is XYZ at YY nautical miles, let the pilot choose which one he wants.
If he chooses the one outside of your FIR, co-ordinate the hand over with the appropriate ATC and hand the flight over in normal manner.
If possible, keep the pilot advised of the actions taken. Inform other traffic of the situation in order to prevent the transfer of traffic to the frequency used for the distress communication.
Assist the aircraft in emergency by the following action with respect to voice communication:
Impose silence on stations interfering with the distress communication. Address such instruction to "all stations" or to a particular station, according to circumstances.
Madrid Tower, To All Stations, stop transmitting, mayday in progress.
When distress communication has ended or when silence is no longer required on the frequency used for distress communication, transmit a message to "all stations" indicating that normal operations can be continued.
Madrid Tower, to All Stations, distress traffic ended