ENR 1.12  Interception Of Civil Aircraft

The following procedures and visual signals apply over the territory and territorial waters of Portugal in the event of interception* of an aircraft.

* The word “interception” in this context does not include intercept and escort service provided, on request, to an aircraft in distress, in accordance with the Search and Rescue Manual (DOC 7333).

1.12.1   Action by intercepted aircraft

1.12.1.1   An aircraft which is intercepted by another aircraft shall immediately:
  1. follow the instructions given by the intercepting aircraft, interpreting and responding to visual signals in accordance with the specifications
  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.

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.

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.

1.12.2   Radio communication during interception

If radio contact is established during interception but communication in a common language is not possible, attempts must be made to convey instructions, acknowledgement of instructions and essential information by using the phrases and pronunciations contained in the following tables hereunder and transmitting each phrase twice:

1.12.2.1.1   Phrases for use by INTERCEPTING aircraft:
PhrasePronunciation*Meaning
CALL SIGNKOL - SA - INWhat is your call sign?
FOLLOWFOL - LOFollow me
DESCENDDEE - SENDDescend for landing
YOU LANDYOU LAANDLand at this aerodrome
PROCEEDPRO - SEEDYou may proceed
1.12.2.1.2   Phrases for use by INTERCEPTED aircraft:
PhrasePronunciation*Meaning
CALL SIGN (call sign*)KOL - SA - IN (call sign)My call sign is (call sign)
WILCOVILL - KOUnderstood. Will comply
CAN NOTKANN NOTTUnable to comply
REPEATREE - PEETRepeat your instruction
AM LOSTAM LOSSTPosition unknown
MAYDAYMAYDAYI am in distress
HIJACK *HI - JACKI have been hijacked
LAND (place name)LAAND (place name)I request to land at (place name)
DESCENDDEE SENDI require descent

1.12.3   Signals for use during interception

1.12.3.1   Signals initiated by INTERCEPTING aircraft and responses by INTERCEPTED aircraft:
SeriesINTERCEPTING Aircraft SignalsMeaningINTERCEPTED Aircraft respondsMeaning
1DAY 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 the desired 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 not able to keep pace with the intercepting aircraft, the latter is expected to fly a series of racetrack patterns and to rock the aircraft each time it passes the intercepted aircraft.You have been intercepted.Follow me.DAY OR NIGHT - Rocking aircraft.flashing navigational lights at irregular intervals and following.Understood, will comply.
2DAY or NIGHT - An abrupt break-away manoeuvre from the intercepted aircraft consisting of a climbing turn of a 90 degrees or more without crossing the line of flight of the intercepted aircraft.You mayproceed.DAY OR NIGHT - Rocking the aircraft.Understood will comply.
3DAY or NIGHT - Lowering landing gear (if fitted), showing steady landing lights and overflying runway in use or, if the intercepted aircraft is a helicopter, overflying the helicopters landing area. In the case of helicopters, the intercepting helicopter makes a landing approach, coming to hover near to the landing area.Land at thisaerodrome.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 landing area, landing is considered safe, proceeding to land.Understood will comply.
1.12.3.2   Signals initiated by INTERCEPTED aircraft and responses by INTERCEPTING aircraft:
SeriesINTERCEPTED Aircraft SignalsMeaningINTERCEPTING Aircraft respondsMeaning
4DAY or NIGHT - Raising landing gear (if fitted) and flashing landing lights while passing over runway in use or helicopter landing area at a height exceeding 300M (1000FT) but not exceeding 600M (2000FT) (in the case of a helicopter, at a height exceeding 50M (170FT) but not exceeding 100M (330FT) above the aerodrome level, and continuing to circle runway in use or helicopter landing area. If unable to flash landing lights, flash any other lights available.Aerodrome you have designated isinadequate.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 mayproceed.
5DAY 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.
6DAY or NIGHT - Irregular flashing of all available lights.In distress.DAY or NIGHT - Use Series 2 signals prescribed for intercepting aircraft.Understood.