The purpose of this section is to simply help you review some of the rules associated with uncontrolled airports.  Just a reminder—there are two types of airports with respect to movement of aircraft arrivals and departures: controlled and uncontrolled.  At controlled airports, there is a control tower, while at uncontrolled airports there is not a control tower.  Of the uncontrolled airports there are essentially two types of procedures, the first applies to ATF and MFA airports, where, on the one hand, there are rigid rules with respect to the movement of aircraft in the circuit and there is no ground station.  The second, on the other hand, applies to MF airports, where rules for aircraft movements are more flexible, and there is a ground station. 1  Now that you are all confused, let us examine the rules associated with airports.

ATF and MFA Airports 2


Prior to taxiing at an uncontrolled airport, broadcast your intention to taxi short of the active runway:

Chilliwack Traffic, Piper Cherokee ABC taxiing to hold short of the Active Runway” (or identify the runway if you know this).


After your pretakeoff checks are completed, broadcast your intentions to move onto the runway:

Chilliwack Traffic, ABC Taxiing to position Runway 24” or, in the case that you require a back-track on the runway “Chilliwack Traffic, ABC Back-tracking Runway 24.”3


In position on the runway, ready for takeoff, broadcast your intentions as well as your anticipated departure direction: Chilliwack Traffic, ABC taking off Runway 24.  Right-hand turnout.  Westbound” or, if your intended altitude is known, Chilliwack Traffic, ABC taking off Runway 24.  Straight Out.  Climbing to 5,500 Westbound.”


As you depart, maintain a track in line with the runway.  Remember that you cannot initiate a turn until you are 1000’ above ground, or at least 1 mile from the departure end of the runway.  Begin your traffic watch immediately.  When you have reached the 1000’ or 1-mile point, report clear of the circuit: Chilliwack traffic, ABC is clear of the circuit, Westbound.”


Chilliwack Airport (ATF)



Begin monitoring the traffic frequency of the destination airport as early as possible, listening for the amount of traffic and the runway in use.  Pay particular attention to other aircraft also broadcasting their arrival as two aircraft arriving at once requires extra vigilance.  (If two aircraft plan to fly inbound, it might be prudent to stay up 500’ above the other traffic until you have visual contact.)


At the five-mile point make your first broadcast.  By this point, if other aircraft are using the airport, you should have had the opportunity to assess which runway you will use and the manner in which you are going to join the circuit.4  However, if there is any doubt as to which runway will be suitable—perhaps because there is no traffic at the airport and you are simply unable to determine the prevailing wind, or perhaps there is so much traffic that you would rather assess the situation—you might simply want to circle above the airport to check things out.5


Circling over the field requires that you maintain an altitude that is at least 500’ above circuit altitude.6  Establish this altitude as you approach the field and make a broadcast accordingly:  Chilliwack Traffic, this is Piper Cherokee ABC 5 miles South of the airport at 4500’, inbound for landing.  I will be descending to 1600 feet and flying over the airport to examine winds and traffic.”  Do not approach the airport from the departure or approach end of the runways; instead, approach mid-field, 90° to the runway.7  While not required, make a gentle left hand turn when you circle above the airport.  Take your time in determining the winds and search for other aircraft.8  Assuming there is no other traffic and the choice of runway is yours, broadcast your intentions once you decide:  “Chilliwack Traffic, ABC mid-field at 1600 feet, I’ll be descending to join Downwind Left hand for Runway 24.”


If other traffic is in the circuit, the mid-field position makes it easy to determine your routing to join the active circuit—simply turn toward the “upwind” or “dead” side of the runway and, flying away from the airport 90° to the runway, begin a descent to circuit altitude.  When you have descended sufficiently, make a left turn back to the mid-field position to cross over the runway to join the downwind leg.  Be sure that you are steady at circuit altitude by the time you cross the runway onto the “active” or “downwind” side.  Then, taking due consideration for other traffic, turn left to join the downwind leg.9


If the active runway is known, it is also safe to simply join the circuit at mid-field without circling over the airport.  Again, approach the field from the upwind or dead side, 90° to the runway at mid-field.  If the circuit is on the far side of the runway relative to your position, you need simply descend to circuit height, cross over at mid-field and make your left hand turn10 onto the downwind leg, giving due consideration to traffic already in the circuit.  If this is your planned course of action, your five-mile broadcast should be as follows:

Chilliwack Traffic, Piper Cherokee ABC, 5 miles north at 5500 feet, inbound for landing.  I will descend to circuit altitude and cross mid-field to join downwind left Runway 24.” When you cross mid-field, broadcast a second time: Chilliwack Traffic, ABC Mid-field, turning downwind left for Runway 24.”


In the event that the active runway is on the same side as you intend to approach the airport, you must cross over the circuit at least 500’ above circuit altitude.  Then when you are safely on the upwind side, make your turning descent to circuit altitude, ensuring again that you are steady at circuit altitude when you cross back over mid-field to join the downwind leg.  When you are at the mid-field point ready to join the circuit, again give the mid-field call as above.  In this method of joining, however, your five-mile broadcast should be different:  “Chilliwack Traffic, Cherokee ABC, 5 miles to the south at 5500 feet, inbound for landing.  I will cross over the field at 1600 feet and descend on the upwind side to join downwind left for Runway 24.”11


A less preferred way of joining the circuit is to join straight in on the downwind leg.  When joining straight in on the downwind leg, begin the downwind track at least three miles from the departure end of the active runway, paying particular attention to departing aircraft and aircraft flying circuits, both of which could be climbing at you with the intent of entering the downwind leg as well.  Your five-mile transmission in this case should be as follows: Chilliwack Traffic, Piper Cherokee ABC is 5 miles south west at 6000’, inbound for landing.  We will descend to circuit altitude and join straight-in for downwind left Runway 24.”  When you reach the downwind leg at the mid-field position, broadcast a downwind position report.


These initial broadcasts can get rather complicated, so you want to be sure you plan your course of action well in advance of your arrival.  Remember as well that you will often have to modify your plans after other aircraft using the airfield advise you of their presence.  To simplify things, it is perhaps best to plan on circling above the airport and using that procedure of arrival—it certainly is the easiest, especially if you are not familiar with an airport.


You are required to provide two additional radio broadcasts, one broadcasting your position on final approach—”Chilliwack Traffic, ABC is on final for Runway 24.  Touch and go”—and the other broadcasting that you are clear of the active runway—Chilliwack Traffic, ABC is down and clear.”


Sechelt-Gibsons Airport (ATF)

MF Airports

Airports with MF procedures are identified in the Canadian Flight Supplement (CFS) under the COMM section, as well as on VFR Navigation Charts (VNC) or VFR Terminal Area Chart (VTA).  For example, information in the CFS for an MF airport appears as follows:


MF - rdo 122.2 5nm 3100 ASL


MF - UNICOM (AAU) ltd hrs O/T tfc 122.75 5nm 3100 ASL


In the first example, FSS facilities are operating at the airport (indicated by “rdo,” and the radio frequency is 122.5 MHz.  The boundary in which MF rules apply extends out 5 nautical miles, and is capped at 3100 feet above sea level.  In the second example, a Unicom (Universal Communication) frequency in which a ground advisory is sometimes provided.


In contrast, VFR charts display the following airport data where MF rules exist:



346 L 50M122.0

The “M” indicates MF procedures, with the particular frequency indicated (in this case 122.0 MHz).  The chart displays the boundaries of the MF airspace.12


In terms of flight operations, aircraft operating with MF boundaries around such airports must be equipped with two-way radios.  MF boundaries should be avoided if possible unless arriving or departing.  MF areas are normally associated with Class E Control Zones and are therefore governed by special weather minima (not less than 3 miles visibility, 1-mile horizontal and 500’ vertical separation from cloud, and 500’ ground clearance).


MF airports usually involve communicating with a Flight Service Station.  It is important to understand that when a FSS administers the MF, “clearances” are not provided.  Instead, the pilot advises FSS of his intentions and positions, while FSS provides traffic and wind information.  So communication should take a similar fashion to broadcasts in uncontrolled airports.


Nanaimo Airport (MF)



If an ATIS (Automatic Terminal Information System) is published, this information must be obtained before entering the MF boundaries. 


On initially contacting the ground station,13 describe your position and intentions and ask for a wind and traffic advisory.  You will be told of the active runway, as well as vicinity traffic.  For example:




“Nanaimo Radio this is Piper Cherokee GABC, 15 miles to the north-west at 7500’, inbound for landing, with Information Alpha (ATIS).  Traffic advisory please.”




“ABC, roger.  Active runway is 16.  Winds 120 at 10 KNOTS.  A Cessna 172 is in the circuit and a Comanche departed northbound three minutes ago.”


Advise the ground station of the arrival procedure you will use—e.g., the altitude at which you will approach and the fashion in which you will join the circuit.




“ABC, roger.  We’ll join right base for 16, descending now to circuit height.”


Remember that the procedures for joining the circuit at an MF airport are far more liberal than at ATF or MFA airport.  Instead of being able to join the circuit only at crosswind at mid-runway or straight in on the downwind leg, you can join a MF circuit using any of the following methods:

  • straight-in on final approach;
  • straight-in on base leg;
  • at a 45° angle to the downwind leg.14

Position reporting is the same as at an ATF airport (downwind, final, and clear).




“Nanaimo Radio, ABC is left base for 16.”




“Roger, ABC.”







“ABC is left base for 16.”




“Roger, ABC.”


Taxi intentions must also be broadcast.




“ABC is down and clear of 16, taxiing for the main ramp.”






Again, monitor the ATIS if available and then ask the ground station for a traffic/wind advisory. 




“Nanaimo Radio this is Piper Cherokee GABC, 122.1.”




“Piper Cherokee GABC, this is Nanaimo Radio, go ahead.”





“GABC is VFR flight planned for LangleyAirport with the

ATIS.  Traffic and wind advisory.”




“ABC, winds 160 degrees at 7 KNOTS.  Active runway 16.”


Broadcast taxi and departure intention as you do at an ATF airport, except direct your transmissions to Nanaimo Radio:




“Nanaimo Radio, ABC is taxiing to hold short Runway 16”




“Nanaimo Radio, ABC, back-tracking Runway 16.”




“Nanaimo Radio, ABC, taxiing to position Runway 16.”




“Nanaimo Radio, ABC, taking off Runway 16, Left hand turn-out.”


Advise the ground station when you are clear of the MF area (this will likely be requested by the ground operator).


Further Readings:


Transport Canada's See, Hear, Comply and Avoid—Maintaining Separation at Uncontrolled Aerodromes


1“ATF” meaning Aerodrome Traffic Frequency, and “MFA” meaning Mandatory Frequency Area; a third abbreviation is “MF” meaning simply Mandatory Frequency.  These abbreviations all apply to airports that lack a control tower, and each established the rules that govern radio communications procedures to be used by vicinity traffic.  The designation appears in Canada Flight Supplement under the COMM section.  Finally, at ATF and MFA airports there is no ground station which pilot communicate with—instead, they communicate with each other; at an MF airport, however, there is a ground station—usually a Flight Service Station—that serves the purpose of relaying traffic advisories—the ground station, however, does not issue “clearances.”  For more information on this, see P. 5 - 2 of the Langley Flying School Initial Groundschool Manual.


2 When Langley Control Tower closes at night, the airport becomes an MFA airport; Chilliwack and Ft. Langley airports also fall into this ground of “uncontrolled” airport operations, but they are ATF airports.


3 Remember that you yourself are responsible for traffic separation, so must be sure the runway will be clear for a takeoff prior to entering.


4 Remember, there is only one way to join an uncontrolled traffic ATF or MFA circuit: joining the downwind leg at circuit altitude (crosswind at mid-field), or straight-in on the downwind leg, providing a conflict does not exist with other traffic.  Your decision, of course, is largely based on your position to the active circuit.


5 In fact, circling over the runway is what most Instructors prefer—it allows you to see the picture prior to committing yourself, and many think it is the safest course of action.


6 If another aircraft is inbound to the same airport and is apparently also planning to circle overhead, you would be advised to circle 1000’ (instead of 500’) above circuit altitude (to ensure separation from the other aircraft); you should broadcast this intention specifying your chosen altitude.


7 As you are likely already aware, the pilot of a departing aircraft has terrible visibility owing to the high nose attitude; similarly, the pilot on final approach tends to be visually “fixated” on the runway.  The approach and departure tracks extending from a runway should therefore be avoided while flying inbound to an airport.


8 Technically and practically, you can circle up there as long as you wish.


9 While approaching the downwind leg at 90° it is really quite easy to fit ahead or behind traffic that is already established in the downwind leg—simply alter course to the right or left.


10 This could be a right turn if right-hand circuits are in effect at the airport.


11 This really is a mouthful isn’t it—with practise you will get the hang of it, and remember there are all sorts of variation in what could be included in this type of radio transmission.  The important thing is that you accurately describe what you are planning to do, with the simple requirement being that it makes sense to other pilots.


12 With respect to MFAs, care has to be exercised because “MF” also appears in the Canada Flight Supplement (CFS), and the erred conclusion might be the MF rules are in effect; in the CFS, however, the notation “tfc 119.0” also appears, and this is what indicates that MFA rules are in effect.


13 Remember that radio contact with the ground station must be made prior to entering the control zone.


14 An additional method not mentioned here, of course, is to fly over the runway to examine traffic and winds—as is normally done at ATF and MFA airports—this is particularly useful during an arrival at an unfamiliar MF airport and allows you to get bird’s eye view of traffic, winds, and the runway layout.