6.3 Acknowledgment, Relay & Other Stations

Everyone else’s job when someone is dying on frequency

Distress is not only the stricken aircraft’s script. RIC-21 §§6.11–6.16 define how other stations transmit, acknowledge, relay, and stay silent. ROC-A candidates who fly traffic patterns or work ground radios are statistically more likely to hear a MAYDAY than to send one. This section is that skill set.

6.11 Action by stations other than the station in distress

An aircraft station that is not in distress should transmit the distress message when:

1. The station in distress is not in a position to transmit the message; or
2. The person in command of the station not in distress believes that further help is necessary; or
3. Although not in a position to render assistance, the aircraft station has heard a distress message which has not been acknowledged

Timing when the aircraft is not nearby

When a distress message is received and it is known that the aircraft is not in the immediate vicinity, sufficient time should be allowed before the distress message is acknowledged. That pause permits stations nearer to the station in distress to reply first. Jumping on a distant MAYDAY with an early acknowledgment can clutter the channel and delay the helper who is two miles away with a visual on the smoke.

Decision tree for non-distress stations

6.12 Action by other stations hearing a distress message

Stations hearing a distress message shall:

1. Continue to monitor the frequency on which the distress message was received and, if possible, establish a continuous watch on appropriate distress and emergency frequencies
2. Notify any station with direction-finding or radar facilities and request assistance, unless it is known that the acknowledging station has done or will do this
3. Cease all transmissions that may interfere with the distress traffic

This is active citizenship on the radio, not passive eavesdropping. Monitoring, DF/radar notification, and silence are three separate duties.

6.13 Distress traffic

Distress traffic consists of all transmissions relative to the immediate assistance required by the station in distress. Essentially, all transmissions after the initial distress call are distress traffic.

Prefacing with MAYDAY once

In distress traffic, the distress signal MAYDAY, spoken once, shall precede all transmissions. Purpose: alert stations that missed the original call but are now on the channel that what they hear is distress-related, not routine.

Example pattern during ongoing coordination:

MAYDAY
WINNIPEG TOWER
THIS IS
PIPER FOXTROT X-RAY QUEBEC QUEBEC
DESCENDING THROUGH ONE THOUSAND FEET
STILL DITCHING EAST OF WINNIPEG

Forbidden transmissions until cancellation

• Any station in the aeronautical mobile service that knows of distress traffic and cannot itself assist shall follow such traffic until it is evident that assistance is being provided
• All stations aware of distress traffic and not taking part are forbidden to transmit on the frequencies used for distress traffic until a message indicates that normal working may be resumed (cancellation of distress)

That ban is absolute enough for exam questions: if you are not part of the distress traffic, you do not squeeze in a position report on that frequency until SEELONCE FEENEE / cancellation procedures clear the channel (next section).

6.14 Acknowledgment of receipt of a distress message

Acknowledgment shall be given in this form:

1. The distress signal MAYDAY
2. The call sign of the station in distress (spoken three times)
3. The words THIS IS
4. The call sign of the station acknowledging (spoken three times)
5. The words RECEIVED MAYDAY

Official RIC-21 example

MAYDAY
PIPER FOXTROT X-RAY QUEBEC QUEBEC
PIPER FOXTROT X-RAY QUEBEC QUEBEC
PIPER FOXTROT X-RAY QUEBEC QUEBEC
THIS IS
WINNIPEG TOWER
WINNIPEG TOWER
WINNIPEG TOWER
RECEIVED MAYDAY

Compare with the distress call (MAYDAY ×3, THIS IS, distressed call sign ×3) and the ack (MAYDAY once, their call sign ×3, THIS IS, your call sign ×3, RECEIVED MAYDAY). Mixing these templates is a common exam failure mode.

6.15 Action by stations acknowledging receipt

After (and as part of) proper handling, stations that acknowledge shall:

1. Immediately acknowledge the distress message
2. Take control of the communications, or specifically and clearly transfer that responsibility, advising the aircraft if a transfer is made
3. Take immediate action so all necessary information goes as soon as possible to the Air Traffic Service (ATS) unit concerned and the aircraft operating agency (or its representative)
4. Continue to monitor the frequency on which the distress message was received and, if possible, any other frequency the station in distress may use
5. Warn other stations, as appropriate, to prevent transfer of aeronautical traffic onto the distress frequency
6. Cease all transmissions that may interfere with distress traffic

Control take / transfer in plain language

If Winnipeg Tower acknowledges, it often takes control: “maintain this frequency,” coordinates rescue, keeps the channel clean. If a relay aircraft acknowledges first, it may transfer control to a ground station with better SAR links—clearly stating the handoff so the distressed pilot knows whom to answer next. Ambiguous “somebody handle this” is not the standard.

6.16 Relay of a distress message

A distress message repeated by a station other than the station in distress shall use:

1. The signal MAYDAY RELAY (spoken three times)
2. The words THIS IS
3. The call sign of the station relaying (spoken three times)
4. The distress signal MAYDAY (once)
5. The particulars of the station in distress (location, nature, persons on board, etc.)

Official-style relay example (RIC-21)

MAYDAY RELAY, MAYDAY RELAY, MAYDAY RELAY
THIS IS
CESSNA NOVEMBER JULIETT INDIA
CESSNA NOVEMBER JULIETT INDIA
CESSNA NOVEMBER JULIETT INDIA
MAYDAY
PIPER FOXTROT X-RAY QUEBEC QUEBEC
STRUCK BY LIGHTNING
DITCHING AIRCRAFT
POSITION: 20 MILES EAST OF WINNIPEG
ALTITUDE: 1500 FEET
AIRSPEED: 125 KNOTS
HEADING: 270 DEGREES
ONE PERSON ON BOARD
PIPER FOXTROT X-RAY QUEBEC QUEBEC

Why MAYDAY RELAY exists

It prevents listeners from thinking you are the aircraft on fire. The triple MAYDAY RELAY plus your call sign, then a single MAYDAY and their particulars, separates relay identity from distress identity. Using a plain MAYDAY ×3 with only your own call sign when you are healthy would be false or confusing distress.

Relay + control reminder

Recall §6.6: control of distress traffic is the responsibility of the aircraft in distress or of the station which relays the distress message—and either may delegate to an aeronautical station with strong ATC/SAR interface. A good relay often ends with successful handoff to tower, centre, or radio.

Worked scenario: distant aircraft hears unacked MAYDAY

1. Hear incomplete MAYDAY on 122.0; no ack for a long interval; you are 80 NM away over remote terrain.
2. Allow a bit more time in case someone closer answers.
3. Still nothing: transmit MAYDAY RELAY with all particulars you heard; notify SAR / ATS by whatever means you have.
4. Monitor continuously; cease other traffic on that frequency.
5. If a nearer station or ATS unit takes over, follow their control instructions and stay quiet unless needed.

Exam traps

Trap 1 — Immediate ack when far away. Allow time for nearer stations when the distressed aircraft is not in your immediate vicinity.

Trap 2 — Ack format errors. Distressed call sign ×3, your call sign ×3, end with RECEIVED MAYDAY.

Trap 3 — Chatting on the distress frequency while not part of distress traffic before cancellation.

Trap 4 — Relaying with MAYDAY ×3 only as if you were the victim. Use MAYDAY RELAY ×3.

Trap 5 — Forgetting ATS / operator notification after you acknowledge.

Drill the acknowledgment and relay scripts aloud until the triple call signs feel automatic.