Sunday, April 22, 2007 - 21:19:21 ET

Landing at an Uncontrolled Airport

There are two "types" of uncontrolled airports, both of which have different rules and procedures.

An uncontrolled aerodrome is one where a control tower does not exist or is not in operation. For example, Buttonville is an uncontrolled aerodrome while the tower is closed (between 2300-0700 local time).

Because the traffic is not controlled, it is important that users of the aerodrome follow the procedures exactly. This ensures that your actions are predictable to other traffic that may be coming and going.

Mandatory Frequency
Aeordromes with a MF specified in the CFS must use this frequency when communicating your intentions to other pilots in the area. This can be a UNICOM or a RCO or a FSS.

In most cases you will be directing your calls to "radio". For example, if you're landing at Muskoka, you'd be broadcasting your radio calls to "Timmins Radio". In this example I usually make the call as "Timmins Radio at Muskoka".

There is a set of calls that must be made in an MF control zone:

(CARS 602.101)
- 5 Minutes before entering the zone. Give your position, altitude, and intentions on how you plan on entering the circuit.
- When joining the circuit
- When on the downwind leg (if applicable)
- When on final approach
- When clear of the active runway

This ensures that everyone else in the area knows where you are and what you're going to do.

When it comes to joining the circuit, there are only two ways:

- Mid-Downwind Leg
- Straight in Downwind Leg

However, if there is traffic advisory available, you may enter the circuit by using the method outlined in the ATF section below.

Aerodrome Traffic Frequency
Aeordromes with an ATF specified in the CFS must use this frequency when communicating your intentions to facility responsible for the airport. In most cases this is an UNICOM.

In most cases you will be directing your calls to "traffic". For example, if you're landing at Peterborough, you'd be broadcasting your radio calls to "Peterborough Traffic"

The same set of calls that you must make at a MF aerodrome are needed at an ATF aerodrome.

When it comes to entering the circuit, your options are as follows:

- Straight-In Downwind Leg
- 45° to the Downwind Leg
- Straight-In Base Leg
- Straight-In Final Leg

(Similar to your options at a controlled airport).

Things To Consider
- If no ATF or MF are published, use 123.2 Mhz
- Some pilots operating under VFR at many sites prefer to give commercial IFR and larger type of aircraft priority. This practice, however, is a personal airmanship courtesy, and it should be noted that these aircraft do not establish any priority over other aircraft operating VFR at that aerodrome.
- IFR Approaches may be made at an uncontrolled airport. If you are a VFR pilot, try to get familiar with what is involved with a "circling approach" so you will understand what an IFR aircraft will do when trying to land at this airport.

Comments (7) | Permalink | Category: Air Law

Hi Blake.

Good info, but I think you might have mixed up the 2 types.

A Mandatory Frequency (MF) is usually associated with a ground station (FSS, RCO, CARS or UNICOM), but if the ground station is not in operation or does not exist, then radio calls are broadcast to "Traffic". An Aerodrome Traffic Frequency (ATF) may have an UNICOM for advisories but radio calls are broadcast to “Traffic”. For example, Buttonville, after the tower closes, is an MF with no ground station so you would broadcast your intentions to “Buttonville Traffic”. Timmins is an MF with an FSS; you would direct you calls to “Timmins Radio”. Muskoka is an MF with an RCO; calls would be made to “London Radio” as the London FSS provides a Remote Aerodrome Advisory Service (RAAS). Peterborough is an ATF with a part-time UNICOM. If the UNICOM was available, you would call them up for an airport advisory and then broadcast your intentions to “Peterborough Traffic”. As for the circuit entries, at an aerodrome without an MF (ATF), or when an airport advisory is not available at an MF aerodrome, the 2 entries (mid-downwind from the upwind side or straight in downwind) apply. At an MF aerodrome with an airport advisory, the other entries you mentioned are allowed.

Again, the info was good, just mixed up in spots. I read your blog and something seemed not right, so I grabbed my AIM and checked out RAC 4.5. It’s a lot of info to try to figure out, hope my explanation clears it up some.

Posted by: Jake's Dad on Monday, April 23, 2007 - 02:43:49

Ahh.. you're right.. I did mix them up. I will fix that in the post.

Muskoka is actually handled by Timmins FSS and not London FSS

Posted by: Blake on Monday, April 23, 2007 - 11:29:53

FWIW, Muskoka used to be handled by London radio up untill some point in the latter half of last year at which point Timmins took over.

Given the last time Jakes Dad probably actually flew up to Muskoka, I'm sure that's what he remembers. :)

Posted by: Mark on Friday, April 27, 2007 - 14:54:33

Hah yeah.. ever since I've been flying, it has been Timmins...

Posted by: Blake on Saturday, April 28, 2007 - 14:45:25

Actually, the last time I flew into Muskoka, the Mandatory Frequency was monitored by Toronto(Buttonville) Radio. When I wrote the reply, I was using an old CFS that I had around the house(not to worry, I always have the correct and current publications available when I fly) and it listed Timmins Radio. And not to be a stickler, but the circuit entries in your post are still reversed. The MF, with the proper advisories, allows the circuit to be entered straight into the downwind, base or final legs. The ATF only allows the mid-downwind from the upwind side or, if no conflict, straight into the downwind. Wouldn't want anyone to get into trouble with TC.

Posted by: Jake's Dad on Saturday, April 28, 2007 - 19:52:34

Jake's Dad:

I reworded some of the text, but unless i'm interpreting the AIM incorrectly, the circuit pattern entries for MF and ATF are correct.

An MF can or cannot have a ground station to provide traffic advisories. If a traffic advisory is *not* available, then you can only enter the circuit via straight-in downwind, or mid downwind.

I did some research and these rules were changed on October 10, 1996. Previously aerodromes with a MF always had a ground station and therefore traffic advisories. With the introduction of the CARs in 1996, MFs were now established without ground stations.

Posted by: Blake on Sunday, April 29, 2007 - 15:10:59

I guess its the ATF circuit entries that I'm talking about. Since there is no one except the pilots to keep track of the circuit traffic (although UNICOM might advise of traffic, it is not an official advisory), the procedures are limited to avoid conflicts. Here is the AIM reference. (RAC4.5.2 - Note 2(v))
http://www.tc.gc.ca/CivilAviation/publications/tp14371/RAC/4-1.htm#4-5-2

(v) Aerodromes not within an MF area: Where no MF procedures are in effect, aircraft should approach the traffic circuit from the upwind side. Alternatively, once the pilot has ascertained without any doubt that there will be no conflict with other traffic entering the circuit or traffic established within the circuit, the pilot may join the circuit on the downwind leg.

Posted by: Jake's Dad on Sunday, April 29, 2007 - 22:30:31