### ENR 1.12 Interception of civil aircraft

#### 1. General

1.1 In accordance with the provisions on interception of civil aircraft in Annex 2 to the Convention on the International Civil Aviation, the national provisions put in place under SERA ensure that:

1. interception of civil aircraft is undertaken only as a last resort;
2. an interception is limited to determining the identity of the aircraft, unless it is necessary to return the aircraft to its planned track, direct it beyond the boundaries of national airspace, guide it away from a prohibited, restricted or danger area or congested areas, or instruct it to effect a landing at a designated aerodrome;
3. practice interception of civil aircraft is not undertaken, unless it has been previously agreed with the pilot-in-command of the aircraft to be intercepted and ATC has been informed accordingly that the interception is to take place;
4. navigational guidance and related information is given to an intercepted aircraft by radiotelephony, whenever radio contact can be established; and
5. in the case where an intercepted civil aircraft is required to land in the territory overflown, the aerodrome designated for the landing is suitable for the safe landing of the aircraft type concerned.

#### 2. Procedures for intercepted aircraft

##### 2.1 Aircraft procedures

2.1.1 The pilot-in-command of a civil aircraft, when intercepted, shall:

1. immediately follow the instructions given by the intercepting aircraft, interpreting and responding to visual signals in accordance with the specifications in Tables 1.12-1 and 1.12-2;
2. notify, if possible, the appropriate air traffic services unit;
3. 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 121.500 MHz, 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 243.000 MHz;
4. if equipped with SSR transponder, select Mode A, Code 7700, unless otherwise instructed by the appropriate air traffic services unit.

Table 1.12-1
Signals initiated by intercepting aircraft and responses by intercepted aircraft
Series | INTERCEPTING aircraft signals | Meaning | INTERCEPTED Aircraft Responds | Meaning
1. | DAY or NIGHT — Rocking aircraft and flashing navigational lights at irregular intervals (and landing lights in the case of a helicopter) from a position slightly above and ahead of, and normally to the left of, the intercepted aircraft (or to the right if the intercepted aircraft is a helicopter) and, after acknowledgement, a slow level turn, normally to the left (or to the right in the case of a helicopter) on thedesired heading. Note 1 Meteorological conditions or terrain may require the intercepting aircraft to reverse the positions and direction of turn given above in Series 1. Note 2 If the intercepted aircraft is notable to keep pace with the intercepting aircraft, the latter is expected to fly a series of race-track patterns and to rock the aircraft each time it passes the intercepted aircraft. | You have been intercepted. Follow me. | DAY or NIGHT - Rocking aircraft and flashing navigational lights at irregular intervals and following. | Understood will comply
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. | DAY or NIGHT - Rocking the aircraft | Understood will comply
3. | DAY or NIGHT - Lowering landing gear (if fitted), showing steady landing lights and overflying the runway in use of, if the intercepted aircraft is a helicopter/ VTOL-capable aircraft, overflying the helicopter/ VTOL-capable aircraft landing area. In the case of helicopters/ VTOL-capable aircraft, the intercepting helicopter/ VTOL-capable aircraft makes a landing approach, coming to hover near to the landing area. | Land at this aerodrome. | DAY or NIGHT - Lowering landing gear (if fitted), showing steady landing lights and following the intercepting aircraft and, if, after overflying the runway in use or helicopter/ VTOL-capable aircraft landing area, landing is considered safe, proceeding to land. | Understood will comply

Table 1.12-2
Signals initiated by intercepted aircraft and responses by intercepting aircraft
Series | INTERCEPTED aircraft signals | Meaning | INTERCEPTING aircraft responds | Meaning
1. | DAY or NIGHT — Raising landing gear (if fitted) and flashing landing lights while passing over runway in use or helicopter/ VTOL-capable aircraft landing area at a height exceeding 300 m (1 000 ft) but not exceeding 600 m (2 000 ft) (in the case of a helicopter, at a height exceeding 50 m (170 ft) but not exceeding 100 m (330 ft) above the aerodrome level, and continuing to circle runway in use or helicopter/ VTOL-capable aircraft landing area. If unable to flash landing lights, flash any other lights available. | 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 (if fitted) and uses the Series 1 signals prescribed for intercepting aircraft. If it is decided to release the intercepted aircraft, the intercepting aircraft uses the Series 2 signals prescribed for intercepting aircraft. | Understood follow me.
Understood, you may proceed.
2. | 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
3. | DAY or NIGHT - Irregular flashing of all available lights. | In distress. | DAY or NIGHT - Use Series 2 signals prescribed for intercepting aircraft | Understood

2.1.2 If any instructions received by radio from 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.
2.1.3 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 by the intercepting aircraft.
2.1.4 If radio contact is established during interception but communication in a common language is not possible, attempts shall be made to convey instructions, acknowledgement of instructions and essential information by using the phrases and pronunciations in Table 1.12-3 and transmitting each phrase twice:

Table 1.12-3
Phrases for use by INTERCEPTING aircraft | Phrases for use by INTERCEPTED aircraft
Phrase | Pronunciation1 | Meaning | Phrase | Pronunciation | Meaning
CALL SIGN | KOL SA-IN | What is your call sign? | CALL SIGN (call sign)2 | KOL SA-IN (call sign) | My call sign is (call sign)
FOLLOW | FOL-LO | Follow me | WILCO | VILL-KO | Understood. Will comply
DESCENT | DEE-SEND | Descent for landing | --- |  |
|  |  | CAN NOT | KANN NOTT | Unable to comply
YOU LAND | YOULAAND | Land at this aerodrome | REPEAT | REE-PEET | Repeat your instruction
|  |  | AM LOST | AM LOSST | Position unknown
PROCEED | PRO-SEED | You may proceed |  |  |
|  |  | MAYDAY | MAYDAY | I am in distress
|  |  | HIJACK3 | HI-JACK | I have been hijacked
|  |  | LAND (place name) | LAAND (place name) | I request to land at (place name)
|  |  | DESCENT | DEE-SEND | I require descent
1.In the second column, syllables to be emphasised are underlined. 2.The call sign required to be given is that used in radiotelephony communications with air traffic services units and corresponding to the aircraft identification in the flight plan. 3.Circumstances may not always permit, nor make desirable, the use of the phrase “HIJACK”

##### 2.2 ATS units procedures

2.2.1 As soon as an air traffic services unit learns that an aircraft is being intercepted in its area of responsibility, it shall take such of the following steps as are appropriate in the circumstances:

1. attempt to establish two-way communication with the intercepted aircraft via any means available, including the emergency radio frequency 121.500 MHz, unless such communication already exists;
2. inform the pilot of the intercepted aircraft of the interception;
3. establish contact with the intercept control unit maintaining two-way communication with the intercepting aircraft and provide it with available information concerning the aircraft;
4. relay messages between the intercepting aircraft or the intercept control unit and the intercepted aircraft, as necessary;
5. in close coordination with the intercept control unit take all necessary steps to ensure the safety of the intercepted aircraft;
6. inform air traffic services units serving adjacent flight information regions if it appears that the aircraft has strayed from such adjacent flight information regions.

2.2.2 As soon as an air traffic services unit learns that an aircraft is being intercepted outside its area of responsibility, it shall take such of the following steps as are appropriate in the circumstances:

1. inform the air traffic services unit serving the airspace in which the interception is taking place, providing this unit with available information that will assist in identifying the aircraft and requesting it to take action in accordance with paragraph 2.2.1;
2. relay messages between the intercepted aircraft and the appropriate air traffic services unit, the intercept control unit or the intercepting aircraft.