Priorities of Communications - What do some of these things even mean?

[YTO]

Hi All. Studying for the ROC-A (yes, another annoying keener with basic questions!!!) and there is a section outlining the Priorities of Communications. While I can memorize this list just fine, it occurs to me that I don't know what some of these items even refer to! Rather than ask a general question, I thought I would share what (I think) I know, for people to correct/clarify/build on this list? Call it penance for asking basic newbie questions!

• 1 - Distress communications.
  Refers to communication about an emergency, such as a MAYDAY call. For example
  MAYDAY MAYDAY MAYDAY
  THIS IS
  FOKKER HOTEL ECHO LIMA PAPA
  FOKKER HOTEL ECHO LIMA PAPA
  FOKKER HOTEL ECHO LIMA PAPA
  PROPELLER HAS FALLEN OFF
  CURRENTLY 15 MILES SOUTH OF SASKATOON
  ATTEMPING LANDING IN FIELD TO THE NORTH OF RIVER
  ALTITUDE: 1000 FEET
  AIRSPEED: 85 KNOTS
  HEADING: 250 DEGREES
  ONE PERSON ON BOARD
  FOKKER HOTEL ECHO LIMA PAPA

• 2 - Urgency communications.
  Refers to urgent communication about an the safety that does not required immediate assistance. For example:
  PAN PAN, PAN PAN, PAN PAN
  BELLEVILLE TOWER
  THIS IS
  CESSNA FOXTROT UNIFORM ECHO LIMA
  PASSENGER IS HAVING A SEIZURE, REQUESTING AMBULANCE ON LANDING
  POSITION: 5 MILES DUE EAST OF BELLEVILLE AERODROME
  AIRSPEED: 105 KNOTS
  ALTITUDE: 1050 FEET
  CESSNA FOXTROT UNIFORM ECHO LIMA
  

• 3 - Communications relating to radio direction-finding.
  I'm not actually sure what this is a reference to, and look to the community for help! Is this as simple a asking as asking info service for vectors?

• 4 - Flight safety messages.
  I'm not actually sure what this is a reference to. Perhaps to avoid certain airspace? Two aircraft in close proximity, in uncontrolled airspace, communicating their movements? Can someone give me an example?

• 5 - Meteorological messages
  Refers to communication about the weather. For example:
  KELOWNA TOWER
  THIS IS
  CIRRUS CHARLIE OSCAR LIMA DELTA
  REQUESTING KELOWNA WEATHER

• 6 - Flight regularity messages.
  Refers to communication regarding the operation or maintenance of facilities essential for the safety or regularity of aircraft operation. This includes:
  • messages concerning the servicing of aircraft;
  • instructions to aircraft operating agency representatives concerning changes in requirements for passengers and crew caused by unavoidable deviations from normal operating schedules
  • messages concerning non-routine landings to be made by the aircraft
  • messages concerning aircraft parts and materials urgently required
  • messages concerning changes in aircraft operating schedules
  For example:
  OTTAWA GROUND
  THIS IS AWESOME AIR TWO NINER NINER
  REQUESTING DE-ICING
  
  or, another example:
  AWESOME AIR DISPATCH
  THIS IS AWESOME AIR FOUR TWO ZERO
  ADVISE PASSENGER LOADING TAKING LONGER THAN PLANNED
  REVISED TIME OF PUSH BACK OH NINE TWO FIVE ZULU
  

• 7 - Messages relating to the application of the United Nations Charter.
  Bueller? Bueller? I have absolutely no idea what this refers to! Can anyone help with a description and/or examples?

• 8 - Government messages for which priority has been expressly requested.
  This seems self explanatory, however I cant think of an example that would not be covered by the other categories. Any ideas?

• 9 - Service communications relating to the workings of the telecommunication service or to communications previously exchanged.
  For example:
  MONCTON RADIO
  THIS IS EMBRAER WHISKEY INDIGO NOVEMBER ECHO
  IM HAVING TROUBLE WITH MY RADIO
  REQUESTING SIGNAL CHECK CHECK 1, 2, 3, 4, 5. HOW DO YOU READ ME?
  OVER
  
  EMBRAER WHISKEY INDIGO NOVEMBER ECHO
  THIS IS MONCTON RADIO
  
  SIGNAL IS EXCELLENT, READING YOU STRENGTH 5

• 10 - All other aeronautical communications.

[ahramin]

1. Correct
2. Correct
3. Anachronism. A lost aircraft can call up a tower or FSS and ask for help. They will direction find the aircraft's radio and tell that aircraft their bearing from the facility. In 25 years of flying I've never heard of it being used. Worst case scenario a lost aircraft could ask atc for help navigating based on their radar position
4. Look up ESCAT
5. More likely you would be asking Pacific Radio for this information but in a pinch any atc unit will pass you weather
6. Mostly an anachronism. 99% of flight regularity messages are passed by ACARS (text messaging between aircraft and company dispatch)
7. Self explanatory if you're willing to read the UN Charter. Otherwise disregard. Example: https://www.youtube.com/watch?v=OaKbZW0pqkM
8. I can't think of one either but you never know
9. Correct

[Dronepiper]

If you ever need to make a mayday call in real life there is no need to report your airspeed (Unless ATC requests it). There are very few reasons why it might assist you. If anything it will just eat up precious time.

[digits_]

Generally, if a life is in danger, a mayday is warranted. A passenger with an unexpected seizure would be a mayday for me.

[telex]

Generally, if a life is in danger, a mayday is warranted. A passenger with an unexpected seizure would be a mayday for me.

You are incorrect.

1.12.1 General
An emergency situation is classified in one of the two following
categories, in accordance with the degree of danger or hazard
present:
a) Distress—A condition of being threatened by serious and/
or imminent danger and of requiring immediate assistance.
The spoken word for distress is MAYDAY, and it is pronounced
three times.
b) Urgency—A condition concerning the safety of an aircraft
or other vehicle, or of some person on board or within sight,
but which does not require immediate assistance. The spoken
word for urgency is PAN PAN, and it is pronounced three
times.

[digits_]

Generally, if a life is in danger, a mayday is warranted. A passenger with an unexpected seizure would be a mayday for me.

You are incorrect.

1.12.1 General
An emergency situation is classified in one of the two following
categories, in accordance with the degree of danger or hazard
present:
a) Distress—A condition of being threatened by serious and/
or imminent danger and of requiring immediate assistance.
The spoken word for distress is MAYDAY, and it is pronounced
three times.
b) Urgency—A condition concerning the safety of an aircraft
or other vehicle, or of some person on board or within sight,
but which does not require immediate assistance. The spoken
word for urgency is PAN PAN, and it is pronounced three
times.

I'd say a passenger with a life threatening condition, possibly resulting in me losing control of the aiprlane if he seizes up and grabs the controls would consititute a distress situation.

I am mentioning this because a lot of new pilots seem to be afraid of using "mayday". Don't be. It's better to declare a mayday when something can still be done, versus waiting and calling mayday when there is a dead body sitting next to you. Then again, you'll probably get the same service from ATC when you declare a pan pan vs a mayday, so the discussion is more of a theoretical one.

Which document did those quoted definitions come from telex?

[telex]

Those definitions come from a relatively obscure document called the Aeronautical Information Manual.

TC publishes it once in awhile. You can download it for free.

Since you bring up the theoretical...

Has there ever been a situation in the history of aviation where a passenger experiencing a seizure seated next to a pilot seized up and grabbed the controls resulting in a situation where a pilot possibly lost control?

[photofly]

What’s the priority for animal noises on 121.5? Does a dog bark get precedence over a miaow?

[NotDirty!]

What’s the priority for animal noises on 121.5? Does a dog bark get precedence over a miaow?

Nothing takes precedence over a meow, especially not in the vicinity of CYAC!

[AirFrame]

4. "any conflicting traffic please advise"
6. Flight regularity - When you had your last movement

Those are the only two I recognised.

[tsgarp]

A good point to remember is that this list of priorities is meant as guidance primarily for ATC and FSS personnel; it helps them determine which radio calls they will make/respond to first in the event that there are multiple catastrophes on the go. You as a pilot are unlikely to ever have to deal with this directly. That said, here’s a few items for consideration on the subject:


MAYDAY: Used when the aircraft/pilot is incapable of staying airborne.
PAN PAN: Used when there is a serious degradation in the situation/aircraft that requires significant deviation from normal procedures.

- these two kind of make sense when you realize they are bastardized French. MAYDAY comes from m’aidez; French for help me. PAN comes from the French word for broken ‘tombe en pan’

Direction Finding is much less common than it was when I first learned to fly, but it is still there. If you look up an airport in the CFS you may see a VDF in the COM section. This stands for VHF Direction Finding. Essentially the ground station can determine your bearing from the station when you transmit. They can use this to give you headings to fly to get to the station, called a DF steer. Brandon still had it, at least they did three years ago.

Safety of Flight Messages relate to thingS like fuel dumping, unplanned NAVIAD outage. A really vivid example was when the Space Shuttle Columbia broke up; ATC warned most of the southern US about falling debris.

Here’s a question; You make your initial contact with tower, and tower replies ‘Alpha Bravo Charlie silence MADAY’. What is going on?

[photofly]

MAYDAY: Used when the aircraft/pilot is incapable of staying airborne.
PAN PAN: Used when there is a serious degradation in the situation/aircraft that requires significant deviation from normal procedures.

Did you invent those definitions?

Does anyone actually use a PAN PAN call in aeronautics? What would the benefit be?

[tsgarp]

MAYDAY: Used when the aircraft/pilot is incapable of staying airborne.
PAN PAN: Used when there is a serious degradation in the situation/aircraft that requires significant deviation from normal procedures.

Did you invent those definitions?

Does anyone actually use a PAN PAN call in aeronautics? What would the benefit be?

They’re the guidelines I use. From a practical standpoint it really doesn’t matter which one you use; both will get ATC’s immediate and undivided attention. From a theoretical standpoint, if there were two simultaneous emergencies on the same frequency ATC would prioritize the MAYDAY over the PAN PAN.

[photofly]

The distinction in maritime usage makes sense to me: MAYDAY requires ships to alter course to assist. PAN merely has them stand by. Maritime law on salvage can make it very expensive to be rescued by a third party, so you don't want to call anyone in unless it's necessary.

In aeronautical usage nobody is coming to assist you while you're still in the air; and you don't have to pay salvage either way. Either you need help, or you don't.

when there is a serious degradation in the situation/aircraft that requires significant deviation from normal procedures.

Sounds like an emergency to me. Whether or not you can stay airborne.

[tsgarp]

In aeronautical usage nobody is coming to assist you while you're still in the air;

Depending on the situation SAR aircraft may be sent to intercept/escort you.

when there is a serious degradation in the situation/aircraft that requires significant deviation from normal procedures.

Sounds like an emergency to me. Whether or not you can stay airborne.

Like I said before; From a practical standpoint, call MAYDAY or call PAN PAN, it makes no difference which. From an academic standpoint; We each have our own criteria for determining what is ‘urgent’ and what is distress. For me, if I’ve made the decision to put the plane on the ground it’s urgency. If the plane has decided to put itself on the ground (and given me only a narrow choice of where it will meet the ground) that’s distress. Other people will have their own criteria, and that’s OK. In an actual emergency safely get the aircraft on the ground and if you have the time and spare cognitive capacity make a radio call. The only caveat that I would add is make sure you use the standard phraseology (MAYDAY or PAN) to indicate the situation to ATC, especially outside English speaking airspace. Many controllers have limited English and are trained to react to standard ICAO phraseology. In these environments ‘declaring emergency’ may not be the same as ‘MAYDAY’ and may not get you the desired response.

[7ECA]

Straight from the ROC-A study guide.

MAYDAY signifies Distress.

Distress: A condition of being threatened by grave and/or imminent danger and requiring immediate assistance

PAN PAN signifies Urgency.

Urgency: A condition concerning the safety of an aircraft or other vehicle, or of someone on board or within sight, but which does not require immediate assistance.

Lots of reasons to call MAYDAY - fire, engine failure, structural issue, etc.

Plenty of reasons to call PAN PAN - low fuel, equipment degradation (all kinds of stuff for the airline ops, ETOPS, etc.), crew illness not directly affecting flight safety (FAs got a dose of the 24 ounce flu, after a layover in Havanna), student pilot got themselves turned around on a XC, etc.

Urgency, can of course turn into Distress.

As discussed, the idea behind the priorities of communication is that in the event of some poor bugger of a controller sitting in a tower at "sumspot" is suddenly inundated with radio calls - there's a way to rank them and give them the priority required.