Multicom???

[Bernoulli]

I know what Unicom is for and I know what CTAF is for, but I can't find any information on multicom in any of my books. How is Multicom different then UNICOM or a CTAF. Thanks in advance for any replies.

 

[avbug]

See AIM 4-1-11. You'll also find reference in the Pilot Controller Glossary.

Multicom - A mobile service not open to public correspondence used to provide communications essential to conduct the activities being performed by or directed from private aircraft.

UNICOM - A nongovernment communication facility which may provide airport information at certain airports. Locations and frequencies of UNICOM's are shown on aeronautical charts and publications.

 

[barnyard]

Don't ask for traffic advisories or landing directions on a multicom.

if you do and if someone does answer you, you will most likely get an extremely sarcastic response.

they're mostly at real small fields without someone to sit at a desk and answer "radio check com 1" or "MN04, airport advisories, please" all day.

 

[Bernoulli]

So is a multicom basically the same thing as a CTAF, but with some radio station on the ground?

 

[LAXSaabdude]

So is a multicom basically the same thing as a CTAF, but with some radio station on the ground?

Actually it's just the opposite. A Multicom has no-one on the ground. It's usually reserved for unattended fields with very little traffic.

LAXSaabdude.

 

[Bernoulli]

So let me get this straight. A CTAF is either a UNICOM or a multicom. The UNICOM has some person on the ground telling aircraft what the winds and traffic pattern is. The multicom has no one on the ground and pilots simply state their intentions and locations to one another. Here is my last question about this subject... I hope. Is there such thing as a CTAF at an airport that is not a UNICOM or a MULTICOM, or does it have to be one or the other.

 

[avbug]

A multicom is not a public use frequency. An example of multicom is a designated frequency for use over a fire or natural disaster.

A CTAF is any frequency that is in common use for broadcasting in the blind, position reporting, etc.

A unicom is a single ground station, which may or may not provide airport or weather information.

You don't use a unicom. You talk to unicom. You will refer to the person answering unicom as XXX unicom. Unicom isn't a frequency or an area traffic; it's a specific station to whom you're addressing a question or comment. You don't speak to area traffic by stating "XXX unicom, four five niner fishface xray is left downwind...". What you would be doing in such a case is telling the person answering the unicom what you're doing, to which an appropriate response might be "Four five niner fishface xray, that's nice. Thanks for letting me know."

You don't talk to CTAF. You use CTAF. You usually refer to XXX area traffic. This is for broadcasting in the blind. It's often the same frequency on which you speak to the unicom...unicom may also be the CTAF frequency. Or not. At part-time towered airports, often the tower frequency becomes the CTAF after the tower is closed, but the unicom stays on a different frequency.

Multicom is something you probably won't be using, or have need to use. Common use is a fire air attack, in which the air attack works all aircraft arriving and departing, and within the temporary flight restriction, coordinates large and small fixed wing, lead aircraft, helicopters, and media ships, as well as air-to-ground traffic. Other possible uses are large law enforcement operations, search and rescue, etc.

 

[Bernoulli]

Thank you AVBUG for a clear and understandable explanation of the three. That clears up my missunderstanding. I only wish the text books I have would simply use examples like you just did when explaining what something is. Thanks again.

 

[LAXSaabdude]

Originally posted by avbug Multicom is something you probably won't be using, or have need to use. Common use is a fire air attack, in which the air attack works all aircraft arriving and departing, and within the temporary flight restriction, coordinates large and small fixed wing, lead aircraft, helicopters, and media ships, as well as air-to-ground traffic. Other possible uses are large law enforcement operations, search and rescue, etc. [/B]

I must really be dating myself then. I got my private in 1987-88, and at the time, Multicom was 122.9, which is what is used for very small, unattended fields. When did they change the designation?

LAXSaabdude.

 

[Ralgha]

No you're not dating yourself, you are correct, Avbug left a small part out.

(MULTICOM FREQUENCY) Activities of a temporary, seasonal, emergency nature or search and rescue, as well as, airports with no tower, FSS, or UNICOM.

That is from AIM Table 4-1-2, a listing of UNICOM and MULTICOM frequency uses as designated by the FCC.

 

[Bernoulli]

Ok... sounds to me that when an airport has no tower, FSS, or UNICOM on the field and the CTAF frequency happens to be 122.9 then that CTAF happens to be called a "MULTICOM", yet it is really no different then any other non-towered airport's generic CTAF frequency. Right?

 

[Ralgha]

Yes, if there is no tower, FSS, or UNICOM, then CTAF is the MULTICOM frequency of 122.9.

Yes I know there are exceptions, but the above statement is generally correct.

 

[YGBSM]

Yes, if there is no tower, FSS, or UNICOM, then CTAF is the MULTICOM frequency of 122.9.

Yes I know there are exceptions, but the above statement is generally correct.

How clear can you get?

 

[Sniper Bob]

If the field is multicom, do you still have to use the OMEGA navigation system for your arrival?