Subchapter 9.2 – IFR Distress and Urgency Communications

Emergency communications under IFR are the highest priority traffic in aviation. When your aircraft faces immediate danger or a serious situation requiring assistance, you declare an emergency using MAYDAY (distress) or PAN-PAN (urgency). These words have no meaning in everyday English; they are pure aviation procedure words with legal, international significance.

MAYDAY is declared when your aircraft faces immediate and life-threatening danger. Examples include:

Engine failure or fire
Structural damage
Uncontrollable descent
Severe medical emergency on board
Fuel exhaustion imminent with no diversion option
Pressurization loss at high altitude
Uncontrollable flight control failure

PAN-PAN is declared when your situation is serious and requires assistance, but is not yet life-threatening. Examples include:

Single-engine failure with an engine still operating (twin-engine aircraft)
Electrical system failure or significant loss of instruments
Hydraulic system failure with backup available
Minor structural damage with aircraft still controllable
Fuel situation degraded but land-able alternatives exist
Medical emergency that is serious but stable
Engine problem with uncertain severity

The distinction matters: MAYDAY triggers emergency response from rescue and fire services. PAN-PAN alerts ATC to prioritize your handling but does not automatically activate rescue. Choose correctly, or ATC may question your declaration.