IFR Clearances -- Whose job are they?
Who do You Call for Clearance?
Departure Instructions
    SIDs
        SID Types
           Vector SIDs
           Pilot NAV SIDs
        Initial Call on Departure on a SID
        Readback of IFR Clearance with a SID
        Controller Quirks with SIDs
        Flight Planning and SIDs
    Clearances Without SIDs
        Unrestricted Climbs
        Detailed Departure Instructions
    Window of Validity
Who Chooses the Departure Runway?
    At a Controlled Airport?
    At an Uncontrolled Airport?
    How to Tell the Difference
 

In the last article, I presented an overview of IFR clearances. The AIM Canada, Paragraph 6.1 refers to Air Traffic Control Clearances as they pertain to IFR flight. "An ATC clearance shall be obtained before take-off from any point within controlled airspace or before entering controlled airspace for flight under IFR or during IMC." This means a pilot must have an ATC clearance to operate within controlled airspace to fly IFR. This week, we'll be looking at the first part of the above statement regarding take-off from any point within controlled airspace. For this segment, we'll assume a point of departure is within controlled airspace, as are the busier airports in Canada from which most pilots are likely to operate.

Whose Job is it to Issue IFR Clearances?

Most IFR ATC units are responsible, either directly or indirectly for separation of IFR aircraft, and therefore responsible for IFR clearances. What is an IFR ATC unit? In Canada, the ATC unit responsible for the provision of IFR control service in a given airspace is called an "IFR unit". At most airports, the Area Control Center, or ACC, is the IFR unit. At the busier airports like Toronto, Vancouver, and Halifax, among others, there is another ATC unit in operation that is primarily responsible for IFR control in the area around these airports. These units are called Terminal Control Units, or TCUs. Not to be confused with the abbreviation for Towering Cumulus, these units work traffic into and out of the busier airports across the country. All but one of our TCUs in Canada are located within its "Parent ACC", or the Area Control Center in whose FIR the unit's airspace lies. Within the ACCs, the TCU generally operates as a separate "specialty", or a group whose controllers work no other airspace than that assigned to the it. Their airspace is called a "Terminal Control Area", or TCA on the charts. There is an additional facet to this in that some Towers, normally considered VFR ATC units that don't provide IFR separation on their own, will provide some degree of control service to IFR aircraft, typically associated with the release of IFR departures with respect to other departures and arrivals at their airport. Still, this authority is delegated to them by the IFR unit whose responsibility it is to work the area around the airport.

Who do you Call for Clearance?

On that note, we'll start at the basics. A diligent pilot has perused the weather, checked the NOTAMs, filed a flight plan, etc. The walkaround has confirmed no problems with the airplane, now it's time for the IFR Clearance. Where does our pilot get it? From the IFR unit. Either directly or indirectly, the IFR unit is responsible for issuing IFR clearances to aircraft. The first place a pilot should look for is a Clearance Delivery position at their airport (in VATSIM, this position is normally suffixed with _DEL). Typically, only the busier airports have a position dedicated to this task. In absence of that position, look for Ground (VATSIM: _GND). In the real world, sometimes the Tower position, working the active runway(s) and aircraft within the Control Zone (CZ) will be staffed by one person, meaning Tower, Ground and Clearance Delivery functions are being provided by one person, and often any frequencies assigned to those positions will be simulcast, or simultaneously broadcast, from one position. A pilot should still call the appropriate position on the appropriate frequency; don't call on the Tower frequency for IFR Clearance or taxi instructions. This is normally the case within VATSIM, as many Towers (suffixed with _TWR) don't have _GND and _DEL as active positions and the Tower is doing it all.

Years ago, many of the lower-volume Towers would call the IFR unit for a clearance when an aircraft on an IFR flight plan made the request. These days, most Towers have interunit arrangements with the ACC/TCU to relay a "canned clearance" (not an official term) that includes a SID, the flight plan route, and a transponder code. Also in this modern era, airports served with Aerodrome Advisory Service (AAS) or Remote Aerodrome Advisory Service (RAAS) by a Flight Service Station (FSS), have engaged in similar procedures whereby an IFR clearance is issued on behalf of the IFR unit to IFR aircraft, but since there is nobody at the airport to exercise control over take-off or taxi clearances, as would be the case with a Tower, there is typically a mention of the fact that a "validation" is required, meaning the clearance is not yet valid and the aircraft is not authorized to depart under the IFR clearance being issued -- at least, not just yet. Another conversation is required before the aircraft is actually allowed to depart.

At some airports, it may still be the case that the Tower or FSS must call the ACC for the clearance. In such cases, the pilots are generally encouraged to wait until the aircraft is ready to taxi before the request is made from the ACC. The ACC controller issues what is appropriate at the time with respect to other IFR traffic for relay to the you in the aircraft through the Tower or FSS. Sometimes there is no Tower or FSS to contact. In this case, call the IFR unit directly, by phone or by frequency if there is a Peripheral Frequency (PAL) for the ACC on or near the airport. The following list was made for VATSIM pilots, but it's pretty close to how pilots in the real world should look for who to contact, as well.

Who to call for IFR Clearance in VatSim:

1. Clearance Delivery (_DEL)
2. Ground (_GND)
3. Tower (_TWR)
4. Terminal (_DEP, or _APP if _DEP isn't online)
5. Center (_CTR)

This is the order of units a pilot should look for. Even though a real world airport may not have a DEL position, the same airport in VATSIM could, if it's a special event. So when a pilot is ready to call for IFR clearance, looking for those units in the list above, in that order, is the way to start. If DEL isn't online, look for a GND controller at your airport. If GND isn't online, look for your airport's TWR. Another note, sometimes the Tower at a nearby airport will obtain and relay clearances for you. Such airports will have it noted in the procedures section of their entry in the Canada Flight Supplement, under PROcedures, which says which ATC unit to call for clearance, and then you would use the same order noted above.

Failing that at your departure airport, look for the IFR unit. How do you know who to call in such a case? You have to know what units operate in your area and whose airspace your airport is in. Have a look at the following grossly-outdated snippet from the aerodrome chart in the Canada Air Pilot for Halifax International Airport in Nova Scotia, CYHZ.

Circled in red, you can see the control agency for departures. When the other units listed from left to right are not in service, you'll call Halifax Departure on 119.2 for clearance. Note in the event that CYHZ_DEP is not in operation, you look for CYHZ_APP, who normally works traffic into and out of Halifax in VATSIM. In real life, you would not have to call CYHZ_DEP for IFR clearance directly, but we don't have real-life staffing in the simulated world. Now, in the case of Shearwater, NS (CYAW), the airport is actually located within the Halifax TCA and is provided terminal control service by Halifax TCU. Here is the similar line from that CAP plate.

You can see that you still call Halifax Departure on 119.2. The difference in appearance is that at CYHZ, you're calling departure associated with the airport where you are. Just like you say, "Halifax Tower" when you're calling the TWR at CYHZ, you're calling "Halifax Departure" when you call departure at CYHZ. In the case of CYAW, you're not calling "Shearwater Departure", so they specify on the plate to call Halifax Departure instead.

Now let's say Halifax Terminal is closed, as happens through the night in real life and many other times in VATSIM. Who do you call then? Well, you look for the ACC in whose FIR CYHZ is located. This happens to be my stomping grounds, Moncton Center, or CZQM_CTR in VATSIM. What frequency? In real life, you could call on 119.2 since that's the one listed in the plate, but in VATSIM, you use whatever frequency is associated with CTR. In the case of a sector split in CTR's airspace, look for something that might give you a clue. For example, if you see CZQM_L_CTR and CZQM_H_CTR, it's probably safe to assume a Low-High split, so call the low controller. You might be wrong, but that controller should politely point you to the right controller in such a case.

Departure Instructions:

What to do with that shiny, new ATC clearance? It depends on what you have received.

At the higher-volume airports, you're likely to get a clearance containing a Standard Instrument Departure, or SID. A SID is defined in the AIM as a planned ATC departure procedure. They provide a transition from the terminal environment to the enroute structure of airspace, and are published with a graphical and textual appearance meant to ease understanding for the pilots and to ensure ATC knows exactly what to expect from the aircraft without having to coordinate each individual aircraft's clearance with detailed departure instructions, as discussed below. The SID normally contains both altitude instructions and navigation instructions, and possibly other items such as noise abatement procedures.

There are different types of SIDs, as well. The Vector SID normally provides the pilot with an altitude and a heading to fly on departure, having the pilot "expect radar vectors to assigned route". The second is a Pilot NAV SID which has specific departure instructions telling the pilot to fly a specified course or VOR radial to a fix and expect further clearance from ATC after departure. Similarly, RNAV SIDs provide pilots with a point-to-point route to fly by use of an RNAV system after take-off. There are also Hybrid SIDs which combine vectors and Pilot NAV/RNAV instructions. Pilot NAV and RNAV SIDs typically contain "transitions" that would be assigned with the SID to take the pilot from the departure runway to a point associated with the enroute structure based on the direction the pilots wants to fly, such as the flight planned route or a Mandatory Route out of the Terminal Area.

Since "one size fits all" doesn't *quite* cut the mustard, there are provisions in each SID to allow for communications failure if something other than the standard communication failure procedures are required. For example, the altitude instructions for all SIDs in the Maritime provinces are to "climb to 5,000 or as assigned". For a Piper Navajo, 5,000 feet may be a reasonable altitude for the flight planned route, but a B747 going from CYHZ to CYYZ really wouldn't like to fly at 5,000 feet all the way. In the event of a comm failure, the pilot can use the comm failure provisions to allow a more appropriate altitude if such a thing were ever to happen.

So what is to be done with a clearance containing a SID? We'll start with the Vector SID. An aircraft has planned a flight in a Dash 8 from CYFC to CYSJ (Fredericton to Saint John, NB) at an altitude of 7,000. Thanks to good flight planning, a pilot can see that restricted area CYR 724, visible in the bottom right hand corner of the SID plate's diagram, prevents filing direct to CYSJ, so the airway V310 is the route, which leaves the YFC VOR on the 097 radial toward FRENN, as shown on this grossly-outdated SID chart. The airway information can be found on the appropriate LO Enroute IFR chart, BTW. Here's an example:

    "Fredericton Ground, CVA116 request IFR to Saint John at 7,000"
    "ATC clears CVA116 to the Saint John Airport, via the Fredericton Six Departure, Flight Planned Route, Depart Runway 33, squawk 3101."

Examine this SID plate example shown at left for CYFC. Looking at the text underneath, you can see that off runway 33, you are expected to fly runway heading, which is a heading of 330° magnetic according to the diagram. Runway heading is also used for Runways 09 and 27. The reason I chose this SID plate as an example, is because the departure instructions for Runway 15 are a little different. Remembering CYR 724 in the bottom right corner of the diagram, the SID can't very well send aircraft off Runway 15 on runway heading like the others since that would put an aircraft into the restricted airspace. To that end, there are two headings published, one heading east and the other heading west. Because not all of the information you need is in the pictorial presentation, the text description must be read, too. Normally on a facing page nowadays, the DEPARTURE ROUTE DESCRIPTION section serves as the textual form of departure instructions, which may include special notes (like trees near the departure path) or special instructions or requirements (such as a minimum climb gradient to a specified altitude due to obstacles near the airport). For Runways 09, 27 and 33, it's quite simple: fly runway heading for vectors, and climb to 5,000 feet. For Runway 15, ATC must specify the transition type, in this case either "Westbound" or "Eastbound". The headings are written for each case, and both have the same altitude assignment as the other three runways, 5,000 feet. Reading the text, you can see it's not just a casual turn on departure. It's a Climbing Right Turn or Climbing Left Turn to tell you to turn immediately after take-off because of the restricted airspace.

Note that above those descriptions there is the "catch all" for ATC: "Unless otherwise assigned by ATC". This would allow ATC to change the departure instructions, if required. If you're only flight planned at 3,000, why would you climb to 5,000? Or if they had traffic overflying the YFC VOR at 4,000, they certainly wouldn't want you climbing to 5,000. They can assign a lower altitude as part of the SID. They can also change the heading with the clearance without canceling the SID. Any modifications to a SID in such a manor require a verbatim readback, just like any IFR clearance. It is the pilot's responsibility to ensure they can comply with any changes to the SID, just as with any IFR clearance. If not, the pilot must advise ATC. Simply reading back the clearance correctly indicates acceptance of the clearance and ATC will expect you to fly it as stated. They will also plan other traffic around you, expecting you will do as you're told. Doing something other than what they gave you just because you didn't like it could have you ending up with a new hood ornament for your Dash 8.

Note for this segment: This chart is nearly 20 years old as of the date of this update, and criteria don't provide for this any longer. This SID was replaced with a new SID with only an eastbound heading for runway 15, and a separate SID for westbound departures on runway 15. History would prove this inadequate, also. The new way of doing this would be to publish a different SID if the same runway is to be used for two separate directions. For example, CYSJ is located southeast of this area, and the departures off runway 32 have a SID for westbound departures and a separate SID for eastbound departures. The other runways are contained on yet another SID to help prevent confusion.

Further, there are communication failure instructions provided in this SID. Because the standard communications failure instructions may not be sufficient, given the departure instructions, they had to give special consideration for just such a case with SIDs. They are pretty clear and concise, so I won't go into further detail here.

So now the pilot has read back the clearance, indicating that acceptance of it. What should the pilot do if given the example clearance above? Well, after departure off Runway 33, the pilot should climb to 5,000 feet, and stay on the runway heading until receiving clearance or instruction from ATC to climb higher or to turn. One distinction here is that the runway heading is to be flown not the runway track. That is, correction for wind drift should not be applied. This is the same with any radar vector from ATC. If the runway heading were 044°, the pilot should fly 044°. Basically, when instructed to fly runway heading, take-off and don't turn.

On initial call up to ATC, the AIM states that you should include these items in your call:

Items to include in initial departure call:

1. Aircraft Callsign
2. Runway of Departure
3. Present Vacating Altitude (to the nearest 100-foot increment)
4. Assigned SID altitude

Why do they want all of that stated? The station being called (Moncton Center) and the Aircraft Callsign (CVA116) are pretty obvious. The runway is simply a safety feature, meaning to remind ATC of what runway the aircraft is departing. The present vacating altitude is stated so ATC can validate the Mode C readout from the aircraft's transponder. ATC can't use the Mode C for separation purposes if it isn't validated, and this is the earliest time to do it. If it's not validated, ATC would have to ask for altitude reports when assigning altitudes and applying separation between aircraft. The report of SID altitude is meant as a confirmation for both pilot and ATC that they are operating on the same page. In VATSIM, even if the same controller is acting as _DEP or _CTR and _TWR at that airport, a pilot should still make an initial call to ATC just as it would occur if the _TWR cleared you for take-off and to switch to the _DEP or _CTR controller.

ATC should respond to the initial call with further climb instructions if a higher altitude can be issued, or provide information on when you can expect a higher altitude if it's not available right away due to traffic. Also, at this point the pilit is technically being vectored to the route assigned in the IFR clearance. In this case, while not depicted as V310 on the SID plate, The YFC 097 radial, which is depicted, happens to be V310, so that's the target of the vector. ATC will consider the presence of other IFR traffic in the vectors that will be issued on departure as the aircraft is directed to the airway. If the aircraft is to be vectored to intercept outside of the airspace depicted on the SID plate, ATC should inform the pilot, and be told where to expect to intercept the route as cleared. Let's continue our example from the departure instructions above.

    "CVA116, Moncton, identified. When able, turn right heading 120. Climb to 7,000"
    "CVA116, turning right heading 120. Climbing to 7,000"

Now the pilot has received clearance to climb to the flight planned altitude. But the turn... What's this wording "when able"? That's ATC's way of allowing a pilot to turn when you're ready, and indicating to you that you're below a safe radar vectoring altitude. This is a CYA (Cover Your Ass) phrase, but it does serve a purpose: the pilot must know a safe altitude has been attained prior to commencing a turn. For example, a note on the SID plate might say, "No turns below 1,300". In such a case, a pilot who checks in at 800 feet shouldn't start that turn right away. It may be worded in other ways, too, like "when able, turn right...", and so forth. If you were above the Minimum Radar Vectoring the controller knows you're safe to do so with respect to obstacles and terrain. If it turns out the heading issued will put you on the airway, the heading may be follow ed by another instruction such as:

    "CVA116 fly present heading to intercept V310 and proceed on course. You're 3 NM north of the YFC VOR"

I think those instructions are pretty straight forward. Now the pilot is joining the enroute segment of flight, so we'll leave this example.

The other form of SID is a Pilot NAV SID. The difference? ATC isn't going to provide navigation by radar vectors on this one. The pilot will have to read the departure instructions and comply with them. An example of this kind of SID is shown by yet-another-grossly-outdated SID plate at left, the Baie Comeau, QC (CYBC), ROGVU 3 Departure. Once again, the pilot must read over the pictorial representation AND the textual description to ensure awareness of all the direction and details when accepting a clearance with such a SID. ATC will provide the pilot with a higher altitude when it becomes available and further clearance beyond the clearance limit issued in the SID in the Departure Route Description when traffic permits. It is expected that this will occur on, or shortly after, initial contact with the IFR unit, in this case Montreal ACC (CZUL_CTR), as the SID informs the pilot to expect further clearance within 10 minutes after departure. Notice the comm failure instructions. The pilot has authorization to proceed to Mont Joli, QC (CYYY) for an approach to land, or to continue enroute. Quite different from standard comm failure proceedures again.

As with any IFR clearance, pilots are not required to accept a clearance with a SID in it. If a pilot has a good reason not to fly a SID, ATC sould be advised that the clearance issued is not acceptable, provided with the reason, and ask for something else. Note this may mean that the pilot may have to wait, since ATC may not be able to issue something else right away, or simply by refusing, the short window of opportunity for your departure might have used up if other traffic is around.

At controlled airports, a clearance with a SID need not be read back in full, as with other clearances. The pilot may readback the aircraft's callsign, and the transponder code if the original ATC clearance contains a SID, as with the example out of Fredericton given earlier. However, ATC may request a full readback, and under this circumstance, the pilot is obligated to provide ATC with the full readback. If the pilot is unclear on one or more parts of the clearance, the pilot should ask for clarification. If there are modifications to the SID, like altitude or heading assignments, then a readback of this information is required, even at a controlled airport.

One final note on SIDs: Pilots should not fly a SID if one was not specifically assigned in the clearance. SIDs are an ATC procedure for departures, not a pilot procedure like an RNAV STAR is for arrivals. If ATC wants a pilot to fly one, it will be assigned as part of the ATC clearance. If a pilot really, really wants to fly one and it's not assigned, that pilot can always ask for it when requesting and amendment to the IFR clearance.

What if the clearance does not contain a SID? There are two ways of issuing a clearance without a SID. These are the methods most likely to be encountered by pilots operating from lower-volume airports, even if a SID is published for the airport in many cases. The first method is to give an unrestricted climb out, the second is to give detailed departure instructions.

The unrestricted climb is useless to ATC for providing separation from other aircraft, so such a clearance will only be issued when there is no other traffic around. They're basically allowing the pilot to do anything within reason to get on course. The area around the Saint John airport, taken from this again-grossly-outdated plate of the Saint John 2 SID, is illustrated at right to give some guidance in this next example. Though I used the SID diagram as a reference for my example, a pilot is only expected to use the SID plate's diagram for navigational reference when actually flying a SID assigned by ATC. For the next example, assume an aircraft departing Saint John Runway 32, and given the following clearance to follow V314 which happens to be the YSJ 288 radial highlighted in red on the diagram:

    "ATC Clears CVA116 to the Princeton airport via V314, maintain 8,000. Squawk 3102."

This means ATC has no reason to restrict the pilot's departure path in any way. They really don't care what you do, so long as the aircraft doesn't wander into CYR 724, the big, bad block of restriced airspace northwest of CYSJ. A pilot could not be faulted for doing any of the following examples, and is not technically limited to these.

1. Depart Runway 32, climb runway heading to intercept the YSJ 288 radial (AKA V314) and proceed on course.
2. Depart Runway 32, turn right direct theYSJ VOR to pick up the airway there.
3. Depart Runway 32, turn left 10° and fly that heading to intercept V314 on course.

The runway in my sample clearance above isn't specified, either, so the pilot could use any other runway and come up with other similar forms of departure plans. The key is to follow what little was specified. That is, don't depart Runway 23 and fly directly to PNN VOR. That wouldn't be flying the airway assigned. The pilot isn't expected to do many specific things with this clearance as issued, but is expected to pick up V314 within a reasonable distance from the YSJ VOR and track that outbound. What you decide to do in such a case comes down to airmanship. If uncertain, the pilot should ask ATC for further instructions and clarification before departing.

Whatever the point of departure, when a pilot calls for IFR clearance the pilot should be ready to write some detailed departure instructions, since ATC may have conditions to be met that require something more specific. In fact, the examples above of what could be done with an unrestricted climb could very well be what ATC assigns. They might have the pilot, "Depart Runway 23, climb runway heading to 6,000 before proceeding on course". Or "Depart Runway 32, climb runway heading to intercept V314 and proceed on course. Not above 4,000 til by MOWND." All kinds of wonderful things could be said here, depending on the traffic situation. As with the SID, and any other IFR clearance, if what is issued is not acceptable, the clearance should be refused and a different clearance requested. If the departure instructions are unclear, because of ambiguous wording, for example, the pilot should ask for clarification before departing.

In both cases of departure clearances, SID or otherwise, one common condition may be a period of validity for the IFR clearance. A pilot may hear words like, "Do not depart until 2345z," which is pretty self-explanatory. The other side of of things is, "Clearance cancelled if not airborne before 2350z." Again, pretty clear. If the clearance contains both of these conditions, there is a five minute window to depart. The clearance is valid when the clock turns to 2345 and 0 seconds, and cancelled (or VOID as our American counterparts say) when the clock rolls over to 2350 and 0 seconds. This means your wheels have to be off the pavement before 2345. Occasionally, you may hear a phrase like, "Do not depart until ACA332 lands". In this case, the pilot can't take-off until the aircraft with the specified callsign lands. If ACA332 conducts a missed approach, that aircraft hasn't landed, so the departing aircraft's clearance is still not valid. In that case, ATC should be contacted for further instructions. Again, if anything is not quite understood, or anything seems ambiguous, clarification should be sought from ATC before departure.

Runway Choice for Departure:

With all that was said above, I didn't talk about who gets to choose the runway for departure. The pilot is ultimately responsible for the safety and operation of the aircraft, so the pilot is the one who decides which runway to be used. This may mean a delay as the pilot may have to wait for other traffic to get the desired runway. If the wait isn't acceptable, the pilot may accept a clearance for another runway. Rules about runway choice differ from controlled to uncontrolled airports, too.

At a controlled airport, the TWR usually determines an active runway based on a number of considerations. These include, but are not limited to, winds, visibility in bad weather, noise abatement requirements, runway surface conditions in the winter time, and so on. Towers have been given guidelines to comply with when choosing runways based on wind direction. When the winds are less than 5 knots, a "calm wind" runway can be chosen. This could be the longest runway that takes departing aircraft away from populated areas, for example. When the winds are higher, other considerations come into play. The maximum crosswind component considered in selecting an active runway is 25 Knots where there is more than one runway at the field. Also, at a controlled airport, an IFR clearance will not always contain a departure runway, since ATC can control an aircraft's departure with taxi instructions and a take-off clearance. If ATC tries to assign a runway that is not suitable for the flight, the pilot may refuse the clearance and ask for something else. The same pilot may also experience delays, since other traffic may be using a runway which will not permit the departure off the desired runway.

At an uncontrolled airport, the pilot has to make this determination based on available information. The good airman will consider items similar to those the controller will consider when selecting an active runway, just as would be the case when evaluating a controller's choice of active runway. At an uncontrolled airport, the IFR controller has neither the responsibility to determine the runway to be used for take-off, nor the authority to assign one. ATC can issue a departure runway as a condition of the IFR clearance, though, if the airport is inside a Class E Control Zone which extends controlled airspace to the ground. It is the pilot's responsibility to ensure the flight can be conducted safely while adhering to the clearance by considering other traffic (including VFR), weather conditions, etc. If a departure off the runway issued in the clearance is unacceptable, the pilot should inform ATC as soon as possible and request an IFR clearance which allows a departure from a different runway. One circumstance that differs from this is if the airport underlies controlled airspace. In this case, ATC may not specify a departure runway, nor may they specify departure instructions that require the use of a particular runway. The difference comes with the classification of airspace surrounding the airport itself. If it's Class G, it is uncontrolled. If it's a Class E control zone, ATC has the right to direct the flow of IFR traffic, but cannot issue take-off clearances and such at the airport. This information can be found in the Canada Flight Supplement and is it usually specified in the airport diagram.

How do you know if you're at a controlled airport or not? In the real world it's simple: if there is a Tower in operation, it's a controlled airport. If there is no tower in operation, it would be an uncontrolled airport. In VATSIM, quite often the APP or CTR controller may be providing an airport control service, and in that case, it is a controlled airport, even without a tower position specifically staffed. If the IFR unit refuses to provide taxi and take-off clearances, operate as though it's an uncontrolled airport.

I hope I've covered all the necessary information for your departure. I intentionally omitted noise abatement procedures, as there are no simulated citizens to wake up in VATSIM when you firewall the throttles. As usual, I want to hear from you if you believe this information is good and relevant, if I've explained something in an unclear way or left something out, or especially if you believe I have made any errors or critical omissions. E-mail me at mo@xlii.ca and let me know. Thanks!