The radiotelephone urgency signal to indicate a condition concerning the safety of an aircraft, vehicle or of some person on board which does not require immediate assistance is
Why this is the answer
Per the TC AIM and radiotelephony procedures, the urgency signal — a safety concern that does not need immediate assistance — is “PAN PAN, PAN PAN, PAN PAN.” MAYDAY is reserved for true distress.
Reference
RTORC – Urgency Communications TC AIM-COM – Emergency Communications TC AIM-SAR – Declaring an Emergency
Question reproduced verbatim from Transport Canada’s PSTAR Study and Reference Guide (TP 11919E). The answer key is Transport Canada’s; the explanation is ours.
A study aid — not a substitute for the official guide, the CARs, or your instructor.