ENR 1.12  INTERCEPTION OF CIVIL AIRCRAFT

1.12.1.  Interception procedures

1.12.1.1 The following procedures and visual signals apply over the territory and territorial waters of the Republic of Cabo Verde 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 International Aeronautical and Maritime Search and Rescue Manual (IAMSAR) Doc 9731.

1.12.1.1.1 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 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 unit control 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 emergency 243.000 MHZ.

1.12.1.1.2 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.
1.12.1.1.3 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 radio instructions given by the intercepting aircraft.

1.12.2.  Radio communication during interception

1.12.2.1 If radio contact is established during interception but communication in a common language is not possible, attempts shall be made to convey 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 (1)Meaning
CALL SIGN KOL SA-INWhat is your call sign?
FOLLOWFO-LOFollow me
DESCENDDEE-SENDDescend for landing
YOU LANDYOU LAANDLand at this aerodrome
PROCEEDPRO-SEEDYou may proceed

(1) Syllables to be emphasised are in bold type.

1.12.2.1.2 Phrases for use by intercepted aircraft:
PhrasePronunciation (1)Meaning
CALL SIGN (call sign) (2)

KOL - SA - IN (call sign)

My call sign is (call sign)
WILLCOVILL - KOUnderstood. Will comply
CAN NOTKANN NOTUnable to comply
REPEATREE - PEETRepeat your instruction
AM LOSTAM LOSTPosition unknown
MAYDAYMAYDAYI am in distress
HIJACK (3)HI - JACKI have been hijacked
LAND (place name)LAAND (place name)I request to land at (place name)
DESCENDDEE SENDI require descent

(1) Syllables to be emphasised are in bold type.

(2) The call sign required to be given is that used in radio telephony communication 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”.

Table 1.12. -1: Visual Interception Signals

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 the desired heading.

Note 1: Meteorological conditions or terrain may require the intercepting aircraft to reverse the positions and directions 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.

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 aircraft.

Understood, will comply.

3

DAY 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 helicopter landing area. In the case of helicopters, the intercepting helicopter 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 interception aircraft and, if, after overflying the runway in use or helicopter landing area, landing is considered safe, proceeding to land.

Understood, will comply.

Signals initiated by intercepted aircraft and responses by interceptor

Series

INTERCEPTED Aircraft Signals

Meaning

INTERCEPTING Aircraft Responds

Meaning

4

DAY or NIGHT - Raising landing gear (if fitted) and flashing landing lights while passing over runway in use or helicopter landing area at height exceeding 300 M (1000 FT) but not exceeding 600 M (2000 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 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.

Understood, follow me.

5

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

DAY or NIGHT - Irregular flashing of all available lights.

In distress.

DAY or NIGHT - Use Series 2 signals prescribed for intercepting aircraft.

Understood.

1.12.3.  Distress Signals

The following signals, used either together or separately, means that grave and imminent danger threatens, and immediate assistance is requested:

  1. A signal made by radio telegraphy or by any other signalling method consisting of the group SOS (... _ _ _... in the Morse Code)

  2. A signal sent by radio telephony consisting of the spoken word MAYDAY.

  3. Rockets or shells throwing red lights, fired one at a time at short intervals.

  4. A parachute flare showing a red light.