MARITIMES SCANNING SITE

STEEP AND FAST: OUTBOUND FROM HALIFAX

Last revised July 3, 2010

Note: Due to the explanations and descriptions here that also are relevant to arrivals
it is best to read this section before you read the arrivals page.

I am NOT a pilot and therefore most of this is based on observation, with a dash of internet searching thrown in.   Anyone with further knowledge who wants to correct or expand, please email me....  marscan1 AT canada.com

Generally speaking an airliner departing an airport gets out of there as fast as economically possible. i.e. head in the direction of the destination as soon as possible, getting up to cruising speed as soon as possible, and get up to cruising height as soon as possible, which translates into as steeply as practical.   You will find that the departure process takes much less time than does the arrival, and therefore you will hear the aircraft on the local frequencies for a much shorter period of time.    Much of the detail included below could be translated into similar situations at other major airports anywhere in North America.    Here in the Maritimes only Halifax has a civilian terminal level of control.   For other airports the same function is carried out directly by Moncton Centre, and in fact in the quiet hours this is the case at Halifax as well, as the terminal control unit (TCU) is not a 24/7 operation.

Here is the sequence that you can follow on your scanner and observe parts of it if you are near the airport.    This is oriented toward the typical airliner operation.

Well ahead of the departure time the airline and the pilot will have analyzed weather patterns and determined the route they wish to take to destination.   There may be differences of opinion between the airline, looking to maximize profit, and the pilot, looking to maximize safety.       Their decisions will be affected by what the air traffic control system can allow in relation to  already planned traffic, and as well the time of departure may be affected by disruptions on the other end.  For example if Jetlink 2851 is scheduled to depart at 0630 but there are problems at Newark, due to weather or whatever, then there may be a delay in leaving Halifax, as there is no point in flying around in circles holding for landing at Newark.      In terms of the actual routes, most airliners heading to Newfoundland go almost direct, those heading to Montreal and Ontario also go more or less direct, which means going through American airspace, but in a few routing varieties.   Most commonly they will head to Millinocket but that can vary.   The aircraft heading to  New York, Philadelphia and Washington can either go down along NS and then along the Maine coast, or very commonly they take what appears to be the longer way by heading inland over Maine, New Hampshire and even Vermont and then heading south more or less along the Hudson River.  This avoids the very heavy traffic coming from Europe and descending into the New York area, but it does use more fuel compared to the more direct route... the thing being however is that the direct route may not work out, as there may be major diversions for traffic. so it is not that simple to compare.

Okay, the aircraft is at the terminal and is not yet fully loaded.     The pilot or first officer will call for clearance on 123.95.   This will be given by the clearance controller, who often will be double duty as the ground controller, and in fact the two frequencies may be simulcast.  The clearance will be either very specific and indicate various waypoints, or it may just refer to the flight plan route.    One quirk is that usually the clearance is to some thing like "the Toronto airport" rather than using the fancier name such as in this case Pearson...     When there is more than one major airport in a city that doesn't happen, so that you will hear LaGuardia and JFK mentioned.

Once the aircraft is ready to go, the pilot will go onto ground control on 121.9 and request permission to pushback and start.

An announcement is made to other aircraft and vehicles on the ramp advisory frequency 122.125.   There is no controller on this frequency so that the only conversation will be between pilots trying to stay out of each others' way.

Once clearing the ramp or earlier, the ground controller will give taxi clearance which will include specific directions to get to the assigned runway.     The runway used is usually the one with the wind most close to head-on, but to some extent and with permission, pilots may request a runway less than ideal for wind, but better for the intended path of travel.    There is a great push to save money wherever possible, even if it is a small amount like $50 of fuel.     Heading 20 miles away from where you want to go and doubling back wastes money and time.

Typically the ground controller will tell the pilot to contact tower when reaching the hold point on the taxiway.   This varies a little depending on the configuration of the particular taxiway.  If the final taxiway is just a short connector to the runway this will be done prior to entering that short section.

The pilot contacts tower on 118.4 and will be told either to wait for traffic or to proceed out onto the runway.    This will either be a directive to "Line up runway xx" or an immediate takeoff clearance with no waiting.   Both are common.

The takeoff clearance will be as follows:  "Air Canada 761 Wind 250 at 15, in the air contact departure (or terminal) 119.2, cleared takeoff runway 23".  The order may be slightly different.

The pilot acknowledges with a readback, and off they go.

The aircraft has just taken off.   It is climbing out, usually on the runway heading.  On occasion the tower controller will give an order to make a turn on takeoff, but this is relatively uncommon.   

Once in the air the pilot switches from the tower frequency (118.4) to the departure frequency (same thing as terminal frequency) which is usually 119.2 (but 118.7 is sometimes used).    The pilot checks in, stating identification and altitude and maybe a few other words.   An example would be "Halifax terminal, Air Canada 603 1500 feet off runway 23"      Terminal will reply to say the aircraft is radar-identified, and then will give the initial altitude and heading directions.     An example would be "Turn right heading 275, climb to flight level 230".

Altitude clearance

Note that for altitudes up to and including 18000 ft the altitude is expressed in feet above sea level.  Above that altitude, it is expressed as a flight level.   Flight level 230 is somewhat equivalent to an altitude of 23000 feet.   In the future I will explain what I mean by "somewhat" but in the meantime you should look up "flight level" in Wiki or elsewhere.

In terms of altitude, the controller will normally give any jetliner a clearance to Flight Level (FL) 230 or 23000 ft.    Propeller driven aircraft do not normally fly as high, nor do aircraft flying to relatively close airports such as Saint John or Moncton, and therefore they will be given lower altitude clearances.   When given an altitude clearance the aircraft will generally climb to it as soon as possible and the controller does not actually dictate the angle of climb.

Direction or Heading Clearance

When an aircraft takes off from Halifax the terminal controller might give the pilot an initial heading in degrees, such as turn right heading 270, or perhaps "Continue runway heading", or might say "Steer 170 vectors for traffic".   The latter is to not only give a heading but to tell the pilot this is in order to avoid other aircraft, it is normally not the heading that the pilot would like due to deviation from the overall intended path.      

Eventually, or in some cases immediately, the controller will not give a heading but rather a destination.    The destination is not the final destination but rather a waypoint that is clearly defined already by name. 

Some of these waypoints are the locations of actual radio navigation beacons, either an NDB (approximately 200 to 500 kHz) or a VOR (108 to 118 MHz).   These are identified by name or by i.d.  VOR's are indentified by a set of three letters, or by their name.  In the US the three letters usually have some relationship to the name and location such as BGR for Bangor, but those in Canada are less likely to relate clearly to the location, such as YYG for Charlottetown.   Note that all Canadian VOR identifiers begin with Y, whereas the American ones can start with any letter.   There are however only a very very few American ones beginning with Y.

Other waypoints or fixes are just points with nothing there!     These latter are used for various purposes in the air traffic control system.    They are identified by five-letter groups, that are pronounced as a word.    Sometimes they do relate to the area they are located in, but usually they are nonsense words.   One of the very common ones around Halifax is ODKAS.  It lies at or above the downtown area of Bedford and is used to line up for runway 05 at Halifax International.  You will not hear it used for outbound clearances, only for inbound.

In either case, in a modern aircraft, the identification can be keyed into instruments and the aircraft will practically fly itself there, and in the case of the NDB's and VOR's there really is no need to actually pick up those radio signals.   At this point I have not listed any NDB based clearances as they are now relatively rare except for smaller aircraft.  Note that some of these points are not far away from Halifax, but some are very far, in particular LEXAK which is near St. John's.    In years gone by other far away clearances often heard were SCUPP near Boston and MAIRE near Montreal.  For some reason these are not heard any more.

Here are the most common clearances given to aircraft on takeoff from Halifax or shortly thereafter.   Some of these are also used by inbound flights, which however use several others very close to the airport for approaches.   Those ones are not listed but will be on a future page.

Under construction.  More details to be added.

The most common outbound clearances are in larger type.

* included on list due to proximity but rarely if ever heard mentioned

Once the clearance is obtained the aircraft is established on the climb and heading, and nothing will be heard until the terminal radar controller determines that the aircraft is leaving the terminal control zone.   This zone is is 35 nm circle around the airport, and with a maximum altitude of 12,500 ft ASL.    Once the altitude or distance is exceeded the aircraft is handed over to the Moncton Centre low level sector controller.      The airspace is divided into sectors each with its own frequency.    I did not say each with its own controller, as that can vary.   In busier times of day there is more likely to be a controller for each sector, whereas in the middle of the night, one controller might have several sectors to watch, and several frequencies.  Whenever a controller has more than one sector, the transmitters are simulcast so that he or she doesn't have to be concerned about picking a transmitter to key up.   The aircraft will continue to use the specific sector frequency.

This passover to Centre is into low level airspace.   Terminal will say something like this: "Eagleflght 4458 contact Moncton Centre on 123 decimal 9."   Sometimes there will be an added comment such as "and advise assigned heading".   

The aircraft then switches over to the assigned frequency and reports as follows:  "Moncton Centre Eagleflight 4458, [present altitude] for FL230".    Moncton will reply, possibly stating that the aircraft is radar identifed, but more likely just clearing it upwards to FL280 which is the uppermost level for low level airspace.   At that time or at any other time there could also be a new heading or waypoint destination given.    Depending on the speed and rate of climb of the aircraft, the time the aircraft spends with the low level controller varies but may be quite short in duration.    If the final cruising altitude will be under FL280 the aircraft will be staying with the low level controller.

The general areas for the low level sectors, in relation to Halifax are as follows and are described in a clockwise direction starting with approximately south of Halifax at the 6 o'clock direction.   From here and around to basically around 9 it is 123.9 MHz.   This is used by aircraft heading more or less south over the Atlantic  and heading to Bermuda and the Eastern Caribbean, and by those heading towards and beyond Yarmouth and along the coast of Maine.   The next sector is used by those heading over southwest NB and on over Maine towards Montreal and Ontario, or to the US Northeast via the inland routes.   The usual frequency for this is 124.3 but 132.5 is also used on occasion.   Heading to Moncton it is 124.4, to PEI 135.65 and to the northeast towards Cape Breton and Newfoundland and beyond it is 135.3.     In the latter case if the aircraft is continuing in low level airspace there will be a further handoff farther along to 118.6 which covers from approximately Antigonish and over Cape Breton Island. 

In the map below there are a few errors.   There is no "Moncton Terminal" but it is true that 124.4 is used only in the vicinity of Moncton airport.    132.5 should appear in the vicinity of 124.3 and 135.5 as all of these are interchangeable or appear to be so.  I did not include the adjacent Boston Center low level frequencies as it is not so likely that a listener in the vicinity of Halifax would hear either side of those conversations.   

If you were near Halifax airport you would have been able to hear both sides of the conversation with tower and terminal.  Depending on altitude you can hear aircraft for long distances, perhaps 300 miles might be a maximum for a listener on the ground if the aircraft is flying at a high altitude such as near FL400.   The ground side is another matter.    I can barely hear the Halifax transmitters from Lower Sackville, not very far away, and it depends on my location.    All the Halifax transmitters, for Ground, Tower, Terminal are located by the Old Guysborough Road (Highway 212) several kilometres northeast of the airport.    Once a the aircraft goes over to Centre you will only hear the aircraft side of things if you live near Halifax.  This is because the ground transmitters for Moncton Centre are not at Halifax and not generally at Moncton.  For example the 123.9 transmitter is in the vicinity of Yarmouth.   118.6 is near Sydney.    There is an exception to this in that 135.3 is at Halifax, and also at night 119.2 becomes a Centre transmitter as well.    This means that for communications on 135.3 you can hear both sides if you are reasonably near Halifax airport.  In fact, at night, in the quieter hours, as mentioned above, some of the transmitters are simulcast, so that you might hear an aircraft transmitting on 123.9 and the reply that is in fact going out over the Yarmouth 123.9 transmitter also coming over the Halifax 135.3 or 119.2 transmitters.

Going back to the progression of events as aircraft depart from Halifax, we are at the phase where the aircraft have come under control of the low level Moncton Centre controllers.    If the aircraft, e.g. jetliners or corporate jets, are heading on up to high level, they will eventually be transferred to the high level controller.   This comes at an altitude of approximately FL280.    For a typical jet heading SW this will happen before they leave Nova Scotia and begin to fly over the Gulf of Maine.    The following map shows the high level frequencies.    Some of those shown as being located in Yarmouth and Sydney, as well as the 133.95 transmitter at Halifax are for traffic passing offshore.    Note that it is quite possible to hear from Halifax aircraft speaking to Boston Center on 128.05, 134.95 and 133.45 but of course you will not hear the ground side of these communications.   It is not as common to hear conversations with Gander but I have done so, as well as a few with Montreal Centre, but this has been with a rooftop beam antenna.    This however ends the scanner listeners ability to listen to aircraft departing from Halifax.   If not done so already you may wish to read about aircraft arriving at Halifax.