IFR Flight Example, Part 2: IFR Clearance

Aviation Topic of the Week
By Michael Oxner, February 1, 2004

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Once again, I feel silly doing it, but I also feel like I have to do it. This week's topic contains clips from outdated charts and these are meant only as reference for the examples. While much of the data hasn't changed since publication, I don't know how much actually has. As always, refer to current, real-world publications for real-world flight. That being said, let's continue on.

This week's topic:

IFR Flight Example, Part 2: IFR Clearance

Last week, our bold pilots flying from Stephenville, NL (CYJT) to Halifax, NS (CYHZ) had surmounted the task of preflight planning. Now, the flight plan is filed, the walk-around is complete, the aircraft is fueled and ready, the passengers are suitably briefed and strapped in. It's time to start up and get ready to go.

How to Obtain IFR Clearance
The IFR Clearance
Interpreting the IFR Clearance

How to Obtain IFR Clearance

Now that the plane is loaded and ready, an IFR clearance must be obtained. In a VFR flight, a pilot would be able to start up and taxi without such a need. With an IFR flight, it's good to have an idea of a few things before start up. Experience goes a long way, here. If in doubt, ask.

A few things about the situation must be considered. Is the departure aerodrome in controlled airspace? The answer for CYJT is, "Yes". A look at LO8, the low level enroute chart that covers this area, reveals that CYJT is in a Class E Control Zone, which means the base of controlled airspace extends to the surface. That means an IFR clearance is needed before take-off, even though a take-off clearance is not. When would an IFR clearance not be required before take-off? If the aerodrome underlies controlled airspace, IFR flight without a clearance is possible, however a flight plan must still be filed and departure and arrival messages must be sent to the responsible IFR unit accordingly. Many aircraft depart aerodromes which underlie controlled airspace and call for IFR clearance when airborne. This is not an option at CYJT, unless a VFR departure is authorized by ATC. Next, who to call for clearance must be determined, and when to call.

The AIP tells us that if a Clearance Delivery position exists at the departure aerodrome, then a call to DEL should be made before start up. Most aerodromes in Canada don't have a DEL position. If DEL doesn't exist, or is closed, a GND position may be contacted. The AIP also says that an IFR clearance will normally be relayed after taxi authorization is issued. Sometimes this may be done before taxi, or even before startup. If in doubt, ask ATC for direction on when to call for clearance. Where do you look to find what communications agencies exist at your airport? At the airport diagram in the Canada Air Pilot (CAP), or in the Canada Flight Supplement (CFS). Below, I've included a sample diagram from an outdated chart for CYJT. have a look.

CYJT

There are three communications agencies listed across the top of the aerodrome chart, none of which are CLNC DEL or GND. The first one is "APRT RDO", and they are not an approved agency for relaying IFR clearances. They operate the station at the field and provide airport advisory, only. Things like winds, altimeter and known airport conditions are relayed by such a station. They do not provide a control service, nor do they normally converse with ATC.

The next one is St. John's Radio on 126.7. One of RDO's normal jobs is the relaying of IFR clearances and other information to pilots from ATC and they also provide a relay of pilot messages to ATC when pilots can't talk to ATC directly. This is another alternative, since the listing of an RCO (Remote Communications Outlet) on such a chart indicates that St. John's Radio may be reachable from the ground. Since a phone conversation with St. John's Radio occurred in our example before departure anyway, the question could be asked then as to who should be contacted for IFR clearance. If there is an entry for RDO with no name (in this example, RADIO is listed with an RCO for St. John's), the Flight Service Station is located at the field and it is normally best to contact this unit and request IFR clearance to be relayed through them if DEL, GND and TWR don't exist at the airport.

Given that ATC in Gander Center has a Peripheral radio frequency (PAL) listed at CYJT in the Canada Flight Supplement (under the entry for Gander Center, CZQX), it may be possible to reach ATC on the ground. This may be appropriate, since often ATC would rather issue a clearance directly when possible, rather than relay through someone who isn't even at the airport.

Flying in and out of Stephenville fairly regularly, our pilots know there are not normally any delays associated with obtaining an IFR clearance. That is, when a pilot calls for IFR clearance, it is typical to obtain a clearance that is valid at the time, instead of being told they'd have to wait for a long time, meaning excessive fuel burn while waiting. Another complication in the winter related to a delay in getting an IFR clearance is de-icing. Most de-icing fluids have a limited "hold over" time during precipitation, so getting an IFR clearance that allows a timely departure can be critical. In any case, CYJT is not an overly busy airport, so even without a TWR in place, getting a clearance from CTR that allows a timely departure isn't normally an issue.

Given the AIP information, and what is known about flying into and out of CYJT, it is decided to start engines and call for IFR clearance just before taxiing. ATC approval for engine start is not required here, as with most Canadian airports. If timing is critical with respect to fuel, it may be advisable to contact the CTR for clearance and use a phraseology like, "Ready to start engines in 5 minutes and requesting IFR." If ATC expects a delay, they should advise the pilot at this point, or simply say something like, "No delay expected. Start up at your discretion and advise ready to copy."

The IFR Clearance

It is decided, given the winds in the weather report (130°T @ 5 knots, or about 150° magnetic), that Runway 09 will be used. With engines started, the COMM radio is tuned to Gander CTR on 132.3, as listed in the CAP chart. After a brief period of listening to ensure other communications aren't "stepped on", the conversation is initiated.

Pilot: "Gander Center, KingAir Foxtrot Alpha Romeo Tango"
CZQX: "KingAir Foxtrot Alpha Romeo Tango, Gander Center"
Pilot: "Alpha Romeo Tango at Stephenville, ready to taxi, request IFR to Halifax, planning departure off runway zero nine"
Since the CTR controller is talking directly to the pilot, rather than relaying through another agency, the phrase "ATC clears..." is not required.
CZQX: "Alpha Romeo Tango is cleared to the Halifax Airport via victor three one nine Sydney, flight planned route. Maintain eight thousand, expect one four thousand thirty miles southwest of Stephenville. Depart runway zero nine, turn right heading two six zero to intercept victor three one nine and proceed on course. Squawk two five four two. Clearance is canceled if not airborne by one six two zero."
The pilot now determines if the clearance is acceptable. Familiarity with the area, situational awareness regarding the flight plan and weather all work together to let the pilot know the above issued clearance is acceptable. We'll discuss hte details below. To acknowledge the clearance, which means "to indicate acceptance and compliance," a verbatim readback -- all words said as spoken by ATC -- is given.
Pilot: "Ok, Alpha Romeo Tango is cleared to the Halifax Airport via victor three one nine Sydney, flight planned route. Maintain eight thousand, expect one four thousand thirty miles southwest of Stephenville. Depart runway zero nine, turn right heading two six zero to intercept victor three one nine and proceed on course. Squawk two five four two. Clearance is canceled if not airborne by one six two zero. We show time 1605z now."
CZQX: "Readback is correct and time checks. Return to the Mandatory Frequency for taxi, and report airborne."
Note that it is not required to check with the time as the pilot here did. Some will, some won't. If a TWR gives a clearance, the time check is normally given anyway.

Interpreting the IFR Clearance

The IFR clearance as issued should not be difficult to understand. For a clearance that doesn't involve a SID this is a good one, since everything is spelled out. Departure instructions are not always specified as they are here, but this leaves little to the imagination of the pilot, and hence, less chance for a surprise to the controller. It seems as though Gander has traffic at 9,000, since ART was only cleared off to 8,000. Since 14,000 was filed, the altitude assigned doesn't qualify under ATC guidelines for an "operationally suitable" altitude. For this reason, ATC has included a location for the pilots to expect clearance to an operationally suitable altitude. In this case, the flight planned altitude at 30 miles southwest of YJT. Note that distances are always nautical miles unless otherwise stated. Part of the pilot's evaluation of the IFR clearance when issued by the CTR was where the higher altitude can be expected. 8,000 feet is above the MEA enroute to YQY, or at least as far as the point where higher can be expected, so that part is acceptable. If the MEA were higher, ATC should be queried about this, though ATC is expected to be aware of such issues when issuing IFR clearances.

CYJT Overview

Another issue when evaluating and interpreting an IFR clearance as issued above is the departure instructions. Do they make sense? The image at right comes from an outdated copy of LO8 and is used as a reference to determine where V319 is in relation to the airport and whether the departure instructions will actually get the aircraft to the airway at an appropriate spot. It is also important to review the take-off minima on the airport diagram in the CAP to see if there are any special departure procedures or if a standard departure profile will work. These have been discussed in past topics, so the Archives can be consulted if there is any question about what these are.

Looking back to the airport diagram above, you can see that the take-off minima box in the bottom left has an asterisk (*) beside the description for "ALL RWYS". This means a pilot must look above in the airport diagram to determine what the special procedures and take-off minima are. For a departure off RWY 09, there are two options. Either depart and make good a climb gradient of 370 feet per nautical mile to 1,800 feet, and then make the turn as instructed by ATC, or depart and climb with visual reference to the surrounding terrain until reaching 1,800 feet and then proceed as cleared by ATC at a normal climb gradient (200 feet per NM) from there. In the first case, the aircraft's speed and climb ability must be considered to ensure obstacle clearance on departure. Consider a climb out at 150 KIAS. This means, in no wind, that the aircraft will cover 2.5 NM in one minute. The required climb rate of 370 feet per NM is multiplied by the number of miles per minute to get the climb rate required in feet per minute. For this example, this results in a required minimum climb rate of 925 feet per minute. Familiarity with the aircraft under different loads, with consideration being given to airport elevation, relative humidity, and temperature, among other factors, help a pilot determine whether or not such a climb gradient can be made. The pilot may opt for a lower forward speed (if the aircraft specs permit) to get a steeper climb gradient. For example, climbing out at 120 KIAS would only require a climb rate of 740 feet per minute. If the pilot is unsure of being capable of maintaining the required climb gradient, departure off another runway should be considered, since it is too late to change your mind once you take-off. Considering the fact that the weather at CYJT, from the weather sequences in last week's topic, was VFR by a fair margin, either option is acceptable.

In either case, the clearance as issued by ATC doesn't conflict with the departure procedures published in the CAP. The departure instructions are reasonable, and compliance is easy. Every aspect of the given clearance is acceptable, so now it's time to "Make it so". The option is made to climb visually to 1,800 for our example.

One more note, the last item in the clearance was, "Clearance canceled if not airborne by 1620". This is always UTC (expressed as "zulu"), and this should be interpreted exactly as read. That is to say, if you're not airborne (which doesn't include "on the runway", or "on the take-off roll") by 1620, it is canceled. Some believe this means the clearance is valid until the end of the minute, or 1620:59. In reality, it means, "your clearance is canceled if you're not in the air when the clock rolls over to 1620". If it is determined that there will not be enough time to get airborne in the window provided, ATC should be notified immediately so that an alternate plan can be made and a new clearance issued. If it is accepted, and subsequently the time is missed, the pilot should contact ATC as soon as practicable to inform them of the situation and obtain a new clearance. Departing with the old clearance that is past its cancelation time is illegal and potentially very dangerous, since the time may have been issued to provide separation between the departing aircraft and an arriving aircraft on approach.

That seems like a lot to accomplish for such a small portion of the flight. In reality, between the flight planning and the actual flying, this is a very small, albeit important part, of the flight. Once the flight is planned and the aircraft is loaded, this whole exchange normally will only take a minute or two. There are an awful lot of important details that need to be considered in the process. I know leaving turbine engines idling for a week will cost a lot in terms of fuel, but this topic would have just grown way too big to get further, so we'll break here. In the meantime, please feel free to e-mail me at moxner@nbnet.nb.ca for feedback or further questions. Thanks for taking the time to read!