Multicom vs area frequency
 

So this is something noted by my instructors recently (see my bolding):

CAAP 166-1 (Dec 2013): "At aerodromes where the carriage of radio is not mandatory, pilots of radio-equipped aircraft should monitor the CTAF and, at a minimum, broadcast their intentions in accordance with the minimum calls set-out in Section 7.3 of this CAAP. Good airmanship also implies that pilots should monitor and broadcast their intentions on the relevant Area Frequency when operating at aerodromes not in ESRA or marked on charts."

It then goes onto say explicitly:

"Note: Feedback from the industry suggests there is some confusion about this procedure, and many pilots are using the Multicom frequency, 126.7 MHz, at aerodromes without a CTAF. Pilots should use the relevant Area Frequency as described above, unless they are in the vicinity of a CTAF aerodrome or in a Broadcast Area."

- We tried this on a navex, got told to bugger off by the area controller.

So the CAAP is telling me to use the area frequency when there is not a CTAF specified. Now if you go to the AIP (GEN) you find the definition of Multicom (126.7) as "Multicom: The frequency (126.7MHZ) used for broadcasts while operating to or from a non--towered aerodrome that does not have a discrete CTAF assigned." With a bit more in GEN 4.5.1.

So, my question is: You're operating at an aerodrome with no designated CTAF and a single radio, what frequency are you on?

There are two conflicting official guidelines here (obviously AIP trumps CAAP from a [technical] legal perspective) which is a detriment to safety.

Gareth.

On a divergent track:

Surely there's enough frequencies available for EVERY airstrip to have a CTAF frequency to get rid of this multicom rubbish (is that scratchy sound I hear someone actually trying to communicate with me from a gyrocopter or is it someone 100NM away?).

Before you pointed out that CAAP, I would have said the Multicom, being 126.7.

Now I'm confused! :confused:

Stay on target, you dirty little Fokker! :}

Doesn't ERSA specify Multicom 126.7 specifically as the CTAF for smaller fields?

Shouldn't be too hard to clear up - even for you bloggs :-)

CTAFs are established wherever shown in AIP - ERSA, maps etc. When operating in a CTAF, monitor and transmit on the CTAF.

When no CTAF is established by AIP, monitor and transmit on 126.7 (as required by AIP). Good airmanship - as per CAAP is also to listen in and transmit intentions on area (in case Joe Bloggs (captains mate...) is flying past.

I suspect your confusion comes from the missing word 'frequency'

An aerodrome can have a CTAF without having a discrete CTAF frequency assigned. In this case - the Multicom and the CTAF are the same.

So, for your examples
- operating to a non-towered, non-CTAF airport with one radio - 126.7.
- operating to a non-towered, CTAF airport without a discrete CTAF (frequency) - 126.7
- operating to a non-towered, non-CTAF airport with two radios - 126.7 and Area

As for being told to bugger off - good airmanship also includes not clogging up airwaves when ATC needs them..... I would think that the CAAP is telling you to make a general broadcast on area when taxing or when 15nm (or so) out. Not to broadcast every leg.

It may do. That's gfunc's point; the CAAP clearly says to use the Area freq when there's no assigned CTAF (by that I assume CASA means "at smaller fields").

Still confused. Is there such an animal? Example? ;)

A quick look thru ERSA showed every airport entry listed a CTAF frequency, and that the smaller ones all used Multicom 126.7

If that's the CTAF, that's the CTAF.

An airport without it's OWN discrete frequency (eg 124.6), therefore 126.7. He means if it doesn't have a frequency listed other than 126.7, then use 126.7.

Bairnsdale and Yarram in Vic would be examples as they don't have their own discreet frequency, so use 126.7.

Unless I am mistaken, I think that's what was intended!

Surely the "good airmanship" comment relates to an area broadcast a la an IFR flight departing an aerodrome outside VHF coverage who is either holding a departure SAR or communicating via HF.

But that would be a best practise assumption...

I want my CTAF discrete frequency and I want it now.

Apart form the Air Services frequency allocation fee, why not?

They both do have a discrete CTAF published in ERSA: 126.7.

Without going through every airport in ERSA to find one that doesn't have a discrete CTAF (which may well be 126.7), the original question stands:

If there's no CTAF published (eg farmer Brown's strip), do you use the Multicom or Area? My money would be on the Multicom.

I would agree with Underneath The Radar. 126.7 for all airstrips without a published CTAF frequency.

Although they really need to give each aerodrome a discrete frequency, it gets stupidly busy at times to the point that someone in the circuit you are joining can't be heard, only because other traffic miles away are transmitting.

The calls certainly should be made no matter how small the strip. All too often I go into smaller strips only to find an aircraft in the circuit not making a single call. Or even better, a glider who ignored my inbound call recently and he was climbing in a thermal ON my inbound track and didn't respond or make a single call after I made 3 inbound calls- and I had to turn to avoid ... Turns out he had a serviceable radio, heard my calls but just didn't know where he was. :confused:

Y'all a bit slow... This AIP amendment was put in 30th May.
Confusions-Maximus now reigns. Been a moot point with CASA ever since, however it is a VERY slow process getting anyone to understand there is a serious contradiction in AIP. However it is being worked on...hopefully...

I was asking exactly the same question when CTAFs were first invented in 1989 or so!

I'm struggling with the use of the work "discrete" in this context as I would consider 126.7 to not be discrete....

Agree with XXX - "discrete" = not 126.7

Who else remembers 119.9 from the sixties / seventies? Its an old concept, just a new acronym to give the appearance of action by CASA

Rubbish Akro. Not CASA's fault at all. All this radio nonsense was caused by he who cannot be named. AFIZ>MTAF>CTAF (R)/Multicom>CTAF... Fortunately someone in CASA finally had the balls to say enough is enough, mandatory radio is the go, and now we might have a stable system for a few years.

CASA, AsA and industry jumping through political hoops for over two decades chasing the septic tank dream. For what? Probably thousands driven out of the industry by continually changing rules and procedures, or driven "underground" where it's taken years and years to get people talking again. Disgraceful.

I forgot MBZs. :}

This subject was discussed at length by all the RAPACs in the late 90's.

There was a choice - At airfields / landing grounds / Farmer Joe's paddock etc that DO NOT have a promulgated CTAF with an associated frequency - ie: Not in ERSA;

Either you publish a frequency for use at such locations,
or
Use the area frequency.

The former was decided upon and in line with our comrades in North America it was called "MULTICOM" - In all cases the MULTICOM is 126.7.

Good airmanship suggests that the area frequency be monitored if you have two comms, but broadcasts should be made on the MULTICOM, unless there is a need to resolve a conflict (or whatever) on the area frequency. IFR ops would use those procedures common with any published CTAFs.

My guess is that the confusion in the CASA document relates to a lack of corporate history and/or understanding of the subject by the writer.

Actually I recall it being 119.1 and it was used at many rural airfields, mainly by aero clubs and flying schools etc.

My understanding of "discrete" is not published (anywhere)...

I’m wondering whether I’ll ever get to read a CAAP for purposes other than amusement. (Perhaps that’s what the second “A” really stands for… :confused:)

Confusion caused by a confused regulator’s attempt to clear up confusion. It’s so … hmmm … Australian. :D

Maybe they should be renamed “CRAPs”.

I think the 166s are generally good value, current discussion point excepted.

Intentional or not, maybe Triadic is on to something. Perhaps the regulator joins the long list of individuals and entities who don't know the difference between 'discrete' and 'discreet'. Maybe they really mean 'discreet' in the sense that it's a close-kept secret.

Bur seriously...how dumb is this? Such a fundamental bit of bread and butter ops obscured by poorly coordinated and worded documentation.

"Contact Kalgoorlie (Flight Service Unit) on 122.1....G'Day....."

How it 'USED' to be.... S I M P L E ......

No Cheers:yuk:

To add to the confusion…

I think what the quoted bits of the CAAP are trying to ‘clarify’ is the frequency that should be used if you are operating at a ‘place’ – to use a neutral term - that is not in ERSA and not marked on charts.

If you are operating in or out of Ma and Pa Kettle’s strip that isn’t in ERSA and not marked on any charts, it seems you should be using the area frequency to make your circuit broadcasts.

If you are operating in or out of a strip that is in ERSA or is marked on charts, you should be using the CTAF specified in ERSA or on the chart or, if no CTAF is specified, 126.7.

This seems to be consistent with AIP ENR 1.1 44.

Dare I say it seems to make sense? If you are operating in and out of a place that isn’t in ERSA and isn’t marked on any chart, aircraft in the vicinity are not going to be listening out for you on 126.7.

If you broadcast “Joining downwind Ma and Pa Kettle’s sheep paddock” on the area frequency, I’m not sure Centre should be complaining.

One of CASA's problems is that they don't seem to have people who really understand what it is they are writing about. Sometimes it appears stuff is just written by someone straight off the street (low experience pilots included).

In their online "Out-n-Back" series, the section about checking NOTAMs has this gem:

"DAH" and "FLIP": Nearly the same sound and number of letters!

"To add to the confusion…

I think what the quoted bits of the CAAP are trying to ‘clarify’ is the frequency that should be used if you are operating at a ‘place’ – to use a neutral term - that is not in ERSA and not marked on charts.

If you are operating in or out of Ma and Pa Kettle’s strip that isn’t in ERSA and not marked on any charts, it seems you should be using the area frequency to make your circuit broadcasts.

If you are operating in or out of a strip that is in ERSA or is marked on charts, you should be using the CTAF specified in ERSA or on the chart or, if no CTAF is specified, 126.7.

This seems to be consistent with AIP ENR 1.1 44.

Dare I say it seems to make sense? If you are operating in and out of a place that isn’t in ERSA and isn’t marked on any chart, aircraft in the vicinity are not going to be listening out for you on 126.7.

If you broadcast “Joining downwind Ma and Pa Kettle’s sheep paddock” on the area frequency, I’m not sure Centre should be complaining."


I think Creamy has it tidily put in a nutshell, so to speak....kaz

I don't think that makes sense at all. Busy CTAFs will have their own CTAF (comprehendi?! :)). All the others seem to have 126.7.

The idea of the Multicom was to have a low-altitude freq for use at light traffic airports (or Ma and Pa Kettle's) so that the Area freq wasn't congested.

IFR would have Area/Discrete CTAF and VFR would have Multicom (if not a discrete CTAF).

I think the CAAP has got it wrong.

Cruising around monitoring the (combined) Area freq(s) getting ready for descent we hear Joe Bloggs at Ma Kettle's place; not the way it should be. He should be on the Multicom. Good on him for talking, but he should be on the "in the vicinity" freq, logically, IMO, the Multicom.

We should start with the question: What do the rules require?

That would lead to an automatic answer to the question: What should the CAAP say?

It is a sad indictment on the state of Australian aviation that the answer to the first question is not instantly and universally known and agreed. :(

Bloggsie: If a VFR bugsmasha is taxiing for take off out of ‘Sandlewood Park’, about 15 nms to the West of Mildura – not in ERSA and not marked as an airstrip on any chart – for a climb to say 9,500 on a track slightly East of North, who’d be assisted by the taxi call being made on 126.7? :confused:

The answer's pretty obvious, as the OP points out: AIP GEN Def of Multicom and ENR 1.4, 3.2.1.

I'll say it again. The CAAP's got it wrong, IMO. Back to the books for you puff! :ouch:

The same people who'd be assisted by departures from any one of the myriad tin-pot airfields listed in ERSA as having a CTAF of 126.7. :) At least we biggies (and the controllers) don't hear their taxiing and entering calls.

I don't necessarily think it's a bad thing farmer Kettle yabbering on the Area when taxiing at his property (I can see both positions); the whole thread, which we seem have come back to, is what the pubs say.

I know what all the various bits of the books say, Bloggsie. ;) The problem is that the sum of all the bits is, demonstrably, confusion (at least for the regulator).

I’ll never be a ‘biggie’, but if I were and I was organising myself for a straight in approach to Mildura from the West, I know on which frequency I’d prefer an aircraft operating from a strip to West of Mildura that isn’t in ERSA or marked on any chart to be broadcasting its taxi call …

Any pilot worth his salt, would make the taxi call on the Multicom (and maybe even on the MIA CTAF due its proximity)for the benefit of other traffic that might be at "Sandlewoood Park" and then once airborne and setting course to climb to A095, would make an appropriate b'cast on the area frequency and the MIA CTAF. Thats how it should work, and dare I say until the CASA comment there was no confusion and it worked fine...!

The 'Biggie' doing the SIA from the West would be at around 3000ft at that distance... If conducting an IFR approach maybe a bit lower, but then our mate would not be climbing to A095...

A broadcast on Multicom then a broadcast on Area then a broadcast on Mildura CTAF? Another variation!

If the second broadcast is desirable, what's the safety issue with making it the first? I am the only person operating in and out of Sandlewood Park: I own it (hypothetically).

I don't understand this statement, triadic:She is climbing to 9,500. That's my point.

If the biggie's SIA call was made before the bugsmasha switches to Area, and the bugsmasha made her taxi call (to herself) on Multicom, they are each blissfully ignorant of the other (unless she makes another broadcast on Area ...).

Thank God we've harmonised with the USA :ok:

Mildura CTAF? IIRC you are supposed to broadcast on the CTAF frequency when in the vicinity of an airfield and your operations may conflict with operations at the airfield.

As I see it, radio broadcasts at this type of strip are primarily about coordinating operations in the circuit i.e. at or below 1000 AGL. Outside the circuit there's not much practical difference between someone planning to land at an unmarked strip, or just flying around.

For your own private strip that isn't marked on charts there is not much value in broadcasting intentions, unless there may be more than one aircraft operating. If you have a BBQ and a dozen of your mates are flying in, and they will be doing a few sightseeing flights as well, there is value in broadcasting taxying/inbound/circuit calls etc. I wouldn't think it would be welcome on area though.

Ahhh, yet another approach: Broadcast on the Mildura CTAF!Really?

So why then would I be broadcasting on the Mildura CTAF when I’m operating out of my unmarked strip 17 nautical miles away? :confused: If it’s because my departure might conflict with traffic tracking into or out of Mildura, why wouldn’t I broadcast on the Area frequency that should be monitored by the traffic tracking into or out of Mildura and near my actual location?

And if CTAF’s just about coordinating circuit traffic, why do I have to broadcast on the CTAF if I’m overflying at 3,500’?

I said "at this type of strip" i.e. in this example, your own private strip. You broadcast overflying a regular CTAF because you might conflict with other aircraft at the airport, e.g. an instrument approach that might begin a few thousand feet above. That's different from a private strip somewhere.

If the broadcast at a private strip is not primarily about conflict during takeoff and landing, why would you broadcast when you are landing at your private strip, but not if you e.g. orbit a neighbors house without a strip?

Ultimately you need to figure out whether you are likely to conflict with other traffic, and if so, what frequency that traffic is most likely to be on. If you expect to conflict with Mildura traffic, Mildura CTAF would seem to be the most likely frequency. If you are too far away from Mildura for the frequency to be applicable, how likely are you to conflict with the traffic, really?

For better or worse, it was decided a long time ago that details of VFR movements should not, in general, be broadcast on the area frequency.

I'm with creampuff.

it is not only about transmitting your intentions, it is also about listening to and developing a situational awareness of conflicting traffic.

what use is transmitting on multicom, then switching to area frequency and transmitting then switching to the nearby ctaf and transmitting if you don't hear the call " :mad::mad::mad: XYZ you are turning directly into my path..."

this is all regulatory incompetence in an area of aviation that was once so simple.