to whom are PAN PAN PAN calls addressed?

Question

Can a PAN PAN situation be adressed directly to an ATC or must it be at adressed only at large?

This is a situation wereby the ATC was the destination before the situation of the pilote got worse.

Answer 1

A PAN call is like a MAYDAY call in that you are broadcasting to whomever may hear it. However, if you broadcast a PAN call on an active ATC frequency, ATC will naturally respond to it and it's sufficient to just state PANPAN-PANPAN-PANPAN and your registration and any other information and ATC will answer, and everybody else will know to stay off the frequency momentarily.

You can broadcast a PAN call on any other frequency like a unicom, or 121.5, and whomever is listening in will likely respond. I was once downed in the bush in a seaplane by engine trouble, becoming stuck on a remote lake, and couldn't raise anybody on the normal unicom channel even if I heard other seaplanes passing in the distance. I saw a contrail above, and knowing airliners monitor 121.5 over sparsely settled areas, I broadcast a PAN call with my registration on 121.5. To my surprise the airliner heard me and answered. I was able to get him to contact base on the Unicom frequency and let them know what lake I was on before he was out of range of my radio's transmitter, and was rescued with my two fisherman passengers later that day. The only other choice was to set off the ELT and hope an airliner or SAR aircraft heard it (this was pre-SARSAT), which would have meant spending the night there at least.

Answer 2

If you are on an ATC frequency, you are communicating directly to ATC while you are communicating at large.

Airband frequencies are not like CB (Citizens Band) frequencies. It is not a free for all. Anyone can listen. But, there are rules to follow if you are transmitting.

For instance, in the U.S., radio communications are not governed by ATC (Air Traffic Control) nor the FAA (Federal Aviation Administration). It is legally regulated by the FCC (Federal Communications Commission). They assign radio frequencies to entities for specific use. When they assign a frequency to ATC for an area (airport, airspace, Flight Information Region, etc), that entity effectively owns that frequency for that area. Others may use it for the express purposes of working with that entity with that entity’s permission.

Think of it like a house that you lease. You effectively own the house, driveway, and lawn for as long as you own the lease. People can not legally enter your property without your permission. Technically, they can walk across your lawn, but not legally. That’s called trespassing. You can have them prosecuted. Most people allow others to walk or drive on their driveway. But, only for the express purposes of coming directly to your front door for your purposes.

If you are communicating on the local frequency, your expectation is for the local entity to respond. If you want to communicate to a different entity, you have to change to a different frequency. Anyone may monitor those frequencies and hear your transmissions. But, they have no legal right to use a frequency owned by someone else except with the owner’s permission.

If ATC owns the frequency, generally, they only want you to communicate directly with them. Communication between planes is discouraged on ATC’s frequency unless it is used to relay messages between a far away plane and ATC or it’s used to communicate urgent information like an open cargo door or fuel leak visible on another plane. I’ve used this to communicate an attached tow bar on a plane crossing the runway hold-short line for takeoff.

Frivolous conversation between planes is even discouraged on frequencies the FCC designated as pilot-controlled. Keep all conversation pertinent to flight operations. Pilot-controlled frequencies are like public city streets or highways. They are owned by the city, county, state or federal government. The public can use them only for specific purposes governed by law.

During a Pan-Pan or Mayday transmission, ATC requires all other transmitters to remain silent unless they can offer assistance to ATC or if ATC addresses them directly. ATC will begin directing the non-emergency aircraft to different frequencies and airspace that will not conflict with the emergency.