Interception of Civil Aircraft: Procedures, Signals, and Emergency Communications

010-05-06Pablo Asensio Martínez2026-03-271 min

Interception of civil aircraft should be avoided and is a measure of last resort. It generally occurs if an aircraft has lost communication, enters airspace without authorization, or deviates from its track in restricted areas.

Action by Intercepted Aircraft

If intercepted by another aircraft, the civil aircraft shall immediately:

  1. Follow the instructions of the intercepting aircraft.
  2. Notify the appropriate ATS unit.
  3. Attempt to establish radio communication with the intercepting aircraft or with the appropriate intercept control unit on the emergency frequency 121.5 MHz (and 243 MHz if possible).
  4. If equipped with a transponder, select Mode A, Code 7700 (unless otherwise instructed).

Visual Signals (ICAO Annex 2, Appendix 1)

  • Passing in front and rocking wings: "You follow me".
  • Abrupt break-away maneuver (climbing turn of 90 degrees or more): "You may proceed".
  • Lowering landing gear and showing steady landing lights: "Land at this aerodrome".

Interception Phraseology (If no common language)

If radio contact is established but there is no common language, the phrases in Table A2-1 shall be used (pronouncing each phrase twice):

INTERCEPTING Aircraft:

  • CALL SIGN: "What is your call sign?"
  • FOLLOW: "Follow me".
  • DESCEND: "Descend for landing".
  • YOU LAND: "Land at this aerodrome".
  • PROCEED: "You may proceed".

INTERCEPTED Aircraft:

  • CALL SIGN (call sign): "My call sign is...".
  • WILCO: "Will comply".
  • CAN NOT: "Unable to comply".
  • AM LOST: "Position unknown".
  • MAYDAY: "I am in distress".
  • HIJACK: "I have been hijacked".