ENR 1.12  INTERCEPTION OF CIVIL AIRCRAFT

1.   INTERCEPTION PROCEDURES

The pilot-in-command of an intercepted aircraft shall:
  1. immediately follow the instructions given by the intercepting aircraft confirming the receipt of signals-commands by using appropriate signals-responses;
  2. notify the appropriate ATS unit;
  3. attempt to establish radio communication with the intercepting aircraft or with the appropriate intercepting control unit, by marking a general call on the 121.5 MHZ emergency frequency, and if no contact has been established, repeat its call on the 243 MHZ emergency frequency, giving its identity (call sign) and position and the nature of the flight;
  4. if an aircraft is equipped with SSR transponder, select Mode A, Code 7700, unless otherwise instructed by the appropriate ATS unit.
If 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 instruction by using the following phrases:
PhrasePronunciationMeaning
WILCOVILL-KOUnderstood, will comply
CAN NOTKANN-NOTTUnable to comply
REPEATREE-PEETRepeat your instruction
AM LOSTAM-LOSSTPosition unknown
MAYDAYMAY-DAYI am in distress
LAND
(place name)		LAAND
(place name)		I require to land at (place name)
DESCENDDEE-SENDI require descent
During interception, the intercepting control unit and the intercepting aircraft shall attempt to establish two-way communication with the intercepted aircraft in a common language on the 121.5 MHZ emergency frequency.
If radio contact with the intercepted aircraft is established but communication in a common language is not possible, the intercepting aircraft shall use the following phrases:
PhrasePronunciationMeaning
FOLLOWFOL-LOFollow me
DESCENDDEE-SENDDescend for landing
YOU LANDYOU-LAANDLand at this aerodrome
PROCEEDPRO-CEEDYou may proceed
If any instructions received by radio from any sources conflict with those given by the intercepting aircraft by visual signals or by radio, the intercepted aircraft shall request immediate clarification while continuing to comply with the signals-commands or radio instructions given by intercepting aircraft.

2.   SIGNALS FOR USE IN THE EVENT OF INTERCEPTION

Signals - command of intercepting aircraft and signals-responses by intercepted aircraft.
SeriesSignals of intercepting aircraft Responses by intercepted aircraft
MeaningActions by intercepting aircraftMeaningActions by intercepted aircraft
1You have been intercepted, follow meAEROPLANES and HELICOPTERS:Understood, will complyAEROPLANES:
DAY – Rocking winds (rocking aircraft) from a position slightly above and ahead of, and normally to the left of the intercepted aircraft and, after acknowledgement, a slow level turn, normally to the left, on to the desired headingDAY – Rocking wings and following the intercepted aircraft
NIGHT - Same actions as by day and, in addition, flashing navigational and landing (if carried) lights at irregular intervals
NIGHT – Same actions as by day and, in addition, flashing navigational and landing (if carried) lights at irregular intervalsHELICOPTERS:
DAY OR NIGHT - Rocking aircraft, flashing navigational and landing lights at irregular intervals and following the intercepted aircraft
NOTES:
1 - Meteorological conditions or terrain may require the intercepting aircraft to take up a position slightly above and ahead of, and to the right of the intercepted aircraft and to make the subsequent turn to the right
2 - If the intercepted aircraft is not able to keep pace with the intercepting aircraft, the latter is excepted to fly a series of race-track patterns (two 180° turns) and to rock wings (aircraft) each time it passes by the intercepted aircraft
2You may proceedAEROPLANES and HELICOPTERS:Understood, will complyAEROPLANES:
DAY OR NIGHT - An abrupt break- away manoeuvre from the intercepted aircraft consisting of a climbing turn of 90° or more without crossing the line of flight of the intercepted aircraftDAY OR NIGHT - Rocking wings
HELICOPTERS:
DAY OR NIGHT - Rocking aircraft.
3Land at this aerodromeAEROPLANES and HELICOPTERS:Understood, will complyAEROPLANES:
DAY - Circling aerodrome, lowering landing gear and overflying runway in direction of landing or, if the intercepted aircraft is a helicopter, overflying the aerodrome (the helicopter landing area)DAY – lowering landing gear, following the intercepting aircraft and, if after overflying the runway landing is considered safe, proceeding to land
NIGHT - Same as in daytime and, in addition, showing steady landing lights
NIGHT – Same as in daytime and, in addition, showing steady landing lightsHELICOPTERS:
DAY OR NIGHT - Following the intercepting aircraft and proceeding to land, showing steady landing lights.
Signals of Intercepted Aircraft And Signals-Responses of Intercepting Aircraft.
SeriesSignals of intercepted aircraft Responses by intercepting aircraft
MeaningActions by intercepted aircraftMeaningActions by intercepting aircraft
4The aerodrome designated from you does not correspond to the type of an aircraft and is inadequate for landing.AEROPLANES:Understood, follow meAEROPLANES:
DAY – Retracting the under-carriage over the runway at a height exceeding 300m but not exceeding 600m above the aerodrome level, and continuing to circling the aerodrome.
NIGHT – Flashing landing lights while passing over the runway at a height exceeding 300 m but not exceeding 600 m above the aerodrome level, and continuing to circle the aerodrome. If unable to flash landing lights, flash any other lights available.		DAY OR NIGHT - If it is required that the intercepted aircraft should follow intercepting aircraft to an alternate aerodrome, the intercepting aircraft retracts the under-carriage and uses the Series 1 signals prescribed for intercepting aircraft.
HELICOPTERS:HELICOPTERS:
DAY - Passing over the aerodrome (helicopter landing area) at a height exceeding 50m but not exceeding 100m above the aerodrome (helicopter landing area) level and continuing to circling.
NIGHT – Flashing landing and navigational lights while passing over the aerodrome (helicopter landing area) at a height exceeding 50m but not exceeding 100m above the aerodrome (helicopter landing area) level and continuing to circling.		DAY OR NIGHT - If it is required that the intercepted aircraft should follow intercepting aircraft to an alternate aerodrome, (helicopter landing area) the intercepting aircraft uses the Series 1 signals prescribed for intercepting aircraft.
Understood, you may proceedAEROPLANES AND HELICOPTERS:
DAY OR NIGHT - If it is decided to let intercepted aircraft proceed, the intercepting aircraft uses the Series 2 signals for intercepting aircraft.
5Cannot complyAEROPLANES and HELICOPTERS:UnderstoodAEROPLANES and HELICOPTERS:
DAY OR NIGHT - Regular switching on and off of all running lights but in such a manner to be distinct from flashing lights.DAY OR NIGHT - Use the Series 2 signals prescribed for intercepting aircraft.
6In distressAEROPLANES and HELICOPTERS:UnderstoodAEROPLANES and HELICOPTERS:
DAY OR NIGHT - Irregular flashing of all available lights.DAY OR NIGHT - Use the Series 2 signals prescribed for intercepting aircraft