I85PREP
⌘ K
NCAA Aeronautical Station Operator study materials
NCAA Aeronautical Station Operator study resources

NCAA Aeronautical Station Operator: Distress, Urgency and Safety Communications

NCAA Aeronautical Station Operator · Work through your exam, one topic at a time.

All guide sections

Distress, Urgency and Safety Communications

Distress, urgency and safety traffic override every other rule in the station. The exam checks your definitions, message order and silence procedures.

Signals and priority

  • Distress: MAYDAY spoken three times, for grave and imminent danger requiring immediate assistance. Highest priority.
  • Urgency: PAN PAN three times, for a condition concerning safety that does not yet require immediate assistance.
  • Safety: SECURITE three times, for important navigational or meteorological warnings.
  • Distress frequencies: 121.5 MHz civil, 243.0 MHz military. 406 MHz is the Cospas-Sarsat ELT frequency.

Procedure

  • Distress message order: MAYDAY three times, callsign, type, nature of distress, intention, position, level, fuel, persons on board, other information.
  • A station acknowledging becomes responsible for the distress traffic or hands it over explicitly. Impose silence with STOP TRANSMITTING, MAYDAY and if necessary SEELONCE MAYDAY; lift it with SEELONCE FEENEE.
  • Relay with MAYDAY RELAY when the station in distress cannot be heard. Notify the rescue coordination centre and ATS, keep continuous watch and log every transmission in UTC.
  • Squawks: 7500 unlawful interference, 7600 radio failure, 7700 emergency.

Worked example. You hear MAYDAY three times from Five November Bravo X-ray reporting engine failure 40 miles south of Kano. Acknowledge, ask for position, level, persons on board and intentions, tell other aircraft to stand by, relay to the rescue centre and ATS, and guard the frequency until the traffic ends.

Traps. Using MAYDAY for an urgency situation; relaying without the words MAYDAY RELAY; letting normal traffic resume while the distress is unresolved; thinking silence applies to the station in distress.