General (ICAO)

ICAO Annex 12 — Search and Rescue defines in Chapter 5.2 (Emergency phases) three emergency levels used by a Rescue Coordination Centre (RCC) to structure the SAR service:

1. INCERFA — Uncertainty phase §5.2.1

When no radio contact exists and contact cannot be established within 30 minutes of attempts to reach the aircraft, or
when an aircraft fails to arrive within 30 minutes of its estimated arrival time (whichever occurs first).

2. ALERFA — Alert phase §5.2.2

After INCERFA, when further attempts to contact the aircraft or relevant enquiries fail to locate it, or
an aircraft has been cleared to land but fails to land within 5 minutes of the estimated landing time and radio contact has not been re-established, or
information indicates the operational efficiency of the aircraft is impaired but not yet a distress situation.

3. DETRESFA — Distress phase §5.2.3

After ALERFA, when further attempts fail to contact the aircraft, or
fuel is exhausted or insufficient to land safely, or
information indicates efficiency is so impaired that a forced landing is likely, or
information indicates with high confidence a forced landing.

Actions per phase: At DETRESFA the search and rescue service is initiated (SAR action).

Europe (EASA / EU)

The ICAO phases are applied via national air-navigation services operating under Regulation (EU) 2017/373 (ATM/ANS — Annex VIII on Air Traffic Services). Coordination of civil SAR responsibility is not EU-harmonised but performed by national authorities per ICAO Annex 12.

Germany (national)

Civil SAR responsibility: Federal Ministry of Transport (BMV) → operationally by the Rescue Coordination Centre (RCC) in Münster for land and in Glücksburg for sea areas (jointly with the Navy).

National rules are in LuftVG (Air Traffic Act) and DFS operating procedures. Pilots trigger emergency phases via 121.5 MHz (emergency frequency) or the responsible FIS sector.