AIP for IRELAND(section ENR-1.12)valid from 14 MAY 2026

ENR 1.12 Interception Of Civil Aircraft

1. Interception of Civil Aircraft

1.1 An aircraft which is intercepted by another aircraft shall immediately:

Follow the instruction given by the intercepting aircraft, interpreting and responding to visual signals in accordance with those listed at 2 below,
Notify, if possible, the appropriate air traffic services unit,
Attempt to establish radio communication with the intercepting aircraft or with the appropriate intercept control unit, by making a general call on the emergency frequency 121.5MHz using the call sign “INTERCEPTED AIRCRAFT” and giving the identity of the intercepted aircraft and the nature of the flight; and if no contact has been established and if practicable, repeating this call on the emergency frequency 243MHz,
If equipped with SSR transponder, select Mode A, code 7700 unless otherwise instructed by the appropriate air traffic services unit.

1.2 If the radio contact with the intercepting aircraft is established but communication in a common language is not possible, attempts shall be made to convey essential information and acknowledgement of instructions by using the following phrases and pronunciations and transmitting each phrase twice: -

PHRASE	PRONUNCIATION	MEANING
CALL-SIGN	KOLSA-IN	My call sign Is (call-sign)
WILCO	VILL-CO	Understood
CAN NOT	KANN-NOT	Unable to comply
REPEAT	REE-PEET	Repeat your instruction
AM LOST	AM LOSST	Position unknown
MAYDAY	MAYDAY	I am in distress
HIJACK	HIJACK	I have been hijacked
LAND (name place)	LAAND (name place)	I request to land at (name place)
DESCEND	DEE SEND	I require descent

The following phrases are expected to be used by aircraft in the circumstances described above
(ICAO Annex, 2, Attachment A refers):

PHRASE	PRONUNCIATION	MEANING
CALL-SIGN	KOLSA-IN	What is your call sign
FOLLOW	FOL-LO	Follow me
DESCEND	DEE-SEND	Descend for landing
YOU LAND	YOU LAAND	Land at this aerodrome
PROCEED	PRO-SEED	You may proceed

1.3 If any instruction received by radio form any sources conflict with those given by the intercepting aircraft by visual signals, the intercepted aircraft shall request immediate clarification while continuing to comply with the visual instructions given by the intercepting aircraft.

1.4 If any instructions received by radio from any sources conflict with those given by the intercepting aircraft by radio, the intercepted aircraft shall request immediate clarification while continuing to comply with the radio instructions given by the intercepting aircraft.

NOTE: The word “interception” in this context does not include intercept and escort service provided on request to an aircraft in distress, in accordance with search and rescue procedures.

2. Signals for use in the event of interception

2.1 Signals Initiated By Intercepting Aircraft And Responses By Intercepted Aircraft

Table 1:
SERIES	INTERCEPTING AIRCRAFT SIGNALS	MEANING	INTERCEPTED AIRCRAFT RESPONDS	MEANING
1	DAY: Rocking wings from a position in front and, normally to the left of intercepted aircraft and after acknowledgement, a slow level turn, normally to the left, on to the desired heading.	You have been intercepted Follow me	AEROPLANES: DAY – Rocking wings and following.	Understood, will comply.
	NIGHT: Same and, in addition flashing navigational lights at irregular intervals.
	Note 1: Meterological conditions or terrain may require the intercepting aircraft to take up a position in front and to the right of the intercepted aircraft and to make the subsequent turn to the right.		NIGHT- Same and, in addition, flashing navigational lights at irregular intervals.
	Note 2: If the intercepted aircraft is not able to keep pace with the intercepting aircraft, the latter is expected to fly a series of race-track patterns and to rock its wings each time it passes the intercepted aircraft.		HELICOPTERS DAY or NIGHT- Rocking aircraft, flashing navigational lights at irregular intervals and following.
			Note- Additional action required to be taken by intercepted aircraft is prescribed in ENR 1-30.
2	DAY or NIGHT- An abrupt breakaway manoeuvre from the intercepted aircraft consisting of a climbing turn of 90 degrees or more without crossing the line of flight of the intercepted aircraft.	You may proceed	AEROPLANES: DAY or NIGHT- Rocking wingsHELICOPTERS DAY or NIGHT- Rocking Aircraft.	Understood, will comply.
3	DAY- Circling aerodrome, lowering landing gear and over-flying runway in direction of landing or, if the intercepted aircraft is a helicopter, over-flying the helicopter landing area	Land at this aerodrome	AEROPLANES DAY- Lowering landing gear, following the intercepting aircraft and, if after over flying the runway landing is considered safe, proceeding to land	Understood, will comply
	NIGHT: Same and, in addition, showing steady landing lights.		NIGHT- Same and, in addition showing steady landing lights (if carried).
			HELICOPTERS: DAY or NIGHT – Following the intercepting aircraft and proceeding to land, showing a steady landing light (if carried).

2.2 Signals Initiated By Intercepted Aircraft And Responses By Intercepting Aircraft.

Table 2:
SERIES	INTERCEPTED AIRCRAFT SIGNALS	MEANING	INTERCEPTING AIRCRAFT RESPONDS	MEANING
4	AEROPLANES: DAY-Raising landing gear while passing over landing runway at a height exceeding 300m (1,000ft) but not exceeding 600m (2,000ft) above the aerodrome level, and continuing to circle the aerodrome.	Aerodrome you have designated is inadequate.	DAY or NIGHT- If it is desired that the intercepted aircraft follow the intercepting aircraft to an alternate aerodrome, the intercepting aircraft raises its landing gear and uses the Series 1 signals prescribed for intercepting aircraft.	Understood, follow me.
4	NIGHT – Flashing landing lights while passing over landing runway at a height exceeding 300m (1,000ft) but not exceeding 600m (2,000ft) above the aerodrome level, and continuing to circle the aerodrome. If unable to flash landing lights, flash any other lights available.	Aerodrome you have designated is inadequate.	If it is decided to release the intercepted aircraft, the intercepting aircraft uses the Series 2 signals prescribed for intercepting aircraft.	Understood, you may proceed.
5	AEROPLANES; DAY or NIGHT- Regular switching on and off of all available lights but in such a manner as to be distinct from flashing lights.	Cannot comply	DAY or NIGHT- Use Series 2 signals prescribed for intercepting aircraft.	Understood.
6	AEROPLANES; DAY or NIGHT- Irregular flashing of all available lights.	In distress	DAY or NIGHT; Use Series 2 signals prescribed for intercepting aircraft.	Understood.
6	HELICOPTERS: DAY or NIGHT- Irregular flashing of all available lights.	In distress		Understood.