Communications
Core concepts
Communications covers radiotelephony phraseology, standard calls, distress and urgency procedures, and the use of the radio. You must know the difference between MAYDAY (distress) and PAN-PAN (urgency), the phonetic alphabet, standard readback requirements, and the correct use of frequencies and transponder codes. Understand the structure of a distress call and the importance of clear, standard phraseology.
Traps to watch
Examiners test whether you know that MAYDAY is repeated three times and is used only for grave and imminent danger, while PAN-PAN is for urgency without immediate danger. A common trap is the readback: clearances and runway instructions must be read back, but not every transmission requires it. Another trap is the transponder code 7700 (emergency), 7600 (radio failure), and 7500 (unlawful interference). Know that the phonetic alphabet is used to spell out ambiguous words, and that "roger" means received, not yes.
Worked example
Engine failure in flight: transmit "MAYDAY, MAYDAY, MAYDAY, [callsign], engine failure, [position], [intentions], [persons on board]." Repeat the callsign three times and keep the message brief.
Rule of thumb
MAYDAY = life-threatening distress; PAN-PAN = urgency. Squawk 7700, 7600, 7500 for emergency, radio failure, and hijack.