Air Traffic Services

Question 1

1St phase for an aircraft in distress

Answer 1

Uncertainty phase (INCERFA) - No comms for 30 mins after it should have been established
An aircraft fails to arrive within 30 of its last ETA or ETA estimated by Atc (whichever is later)

Question 2

2Nd phase for aircraft in distress

Answer 2

Alert phase (ALERFA) - comm attempts have failed and no other news has been received
Aircraft fails to land within 5 mins of its estimated landing time
Info indicates operating efficiency of the aircraft has been impaired
Aircraft is known or believed to be the subject of unlawful interference

Question 3

3rd phase for aircraft in distress

Answer 3

Distress phase(DETRESFA) - all comm attempts have failed or widespread enquires point to the probability that the aircraft is in distress
FOB is exhausted or insufficient to reach safety
Info is received or its reasonably certain that the aircraft has or is about to make a forced landing