Navigation 1.1 - MF vs ATF procedures

When you get closer to your flight exam and more specifically your first cross country flight, you will surely be required to learn MF and ATF procedures. Why is this important? Simple: According to TP's Aviation Safety letter you need to SEE, COMPLY, AVOID and MAINTAIN SEPARATION AT AN UNCONTROLLED AERODROME.

You have probably gathered by now that MF and ATF frequencies and procedures are followed at uncontrolled aerodromes and the simplest way to define those is to think of an airport without a control tower.

This does not mean however there are no rules that govern this airspace, quite the opposite. There are many rules (and recommendations/suggestions) you need to know about before you head out.

When you first read the rules, regulations and in your AIM, you will see many similarities between MF and ATF. To be honest, I had to read a few materials to truly get the differences.

I figured it would be helpful to try to summarize/decipher that info in a more human language, at least something I can remember and understand.

Some general points:

• MF=Mandatory Frequency
  
• ATF= Aerodrome Traffic Frequency
• Both MF and ATF are radio frequencies and procedures used within an uncontrollable aerodrome
• The main difference between MF and ATF is that MF is where the pilot must obay the rules and must communicate with traffic or ground. With ATF they should but do not have to...
• I think it is fair to assume MF area is an area where you can expect more traffic in the air than at ATF area, hence the need for more mandatory rules
  
• MF area is an area around the aerodrome (usually 5 nm radius and up to 3000 AAE, or otherwise stated in CFS) where these rules apply
  
• Unless provided (in your CFS) the agreed on frequency is 123.2
• Within MF area traffic info can be provided by FSS, FIC, CARS, UNICOM and RCO
• When these facilities are closed the area automatically should follow ATF rules
• Within ATF you communicate with traffic (air and ground) and/or UNICOM
• In many cases the uncontrolled aerodrome airspace follows rules of Class E airspace
  

Traffic Circuit Procedures

• For any uncontrolled aerodrome when approaching from upwind, plan to descend to 1000 ft AAE when crossing the runway
• When you need to cross before joining, do so at 500 feet above circuit altitude
• Aerodromes within MF area (with available airport advisory info) may follow standard circuit procedures including circuit pattern straight-in or at 45 degrees to downwind and straight in to the base or final leg (basically the same as where a control tower is in operation)
• The difference for aerodromes when MF is after hrs (not in operation) hence ATF, is that the pilot should not join the circuit straight in to final, base or at 45 degrees to downwind. So, ideally you should join on upwind side or straight into downwind - all of the above when the PIC is sure no conflict with other traffic exists.
  
• If the situation allows and the pilot has confirmed no conflict, can make the decision to join straight in or 45 degrees as (

  remember in ATF you should do, not must do as in MF
  

  ). Here is a real life example when the upwind side was not avail due to soaring activity http://www.avcanada.ca/forums2/viewtopic.php?f=68&t=47839. Some pilots argued the pilot only could have joined straight into downwind (with the upwind being congested) but the truth is he could have joined at 45 degree to downwind or straight into base or even final after confirming no conflict existed...REMEMBER SHOULD IS NOT SHALL

Radio Procedures

• Must listen on MF frequency or should listen on ATF frequency (CFS) or 123.2
• Before entering area report position and intentions (to Radio, traffic, vehicles etc)
• On Departure
• Before entering onto the runway (takeoff surface) report intention
• Ensure no other traffic is in conflict with you before takeoff (collision likelihood is small or null)
• After takeoff report to traffic when leaving the circuit and continue listening till after you leave MF or ATF area
• On Arrival
• Report when entering area (5 mins before), position, intentions, ETA etc
• Report when joining circuit (and give your position within circuit)
• Report when on downwind, then final, when clear of runway after landing
• Continuous circuits
• Report when on in downwind, final (state intentions), report when clear of runway after landing
  
• Flying through the area
• Report before entering area (5 minutes before), IT PAID (Ident, type, Position, Alt, Intentions, Directions (From))
• Report when clear of it
• Best to avoid it to reduce radio congestion
• In most cases plan to pass at least 2000 feet AAE
  

Find more detailed information visit AIM RAC section 4.5.4.

I'm also including a link that summarizes the circuit procedures well. Blake from http://fly.blakecrosby.com has done a great job putting this together. Thanks!

Here you go: CHART