INFO Last updated on 08 OCT 2010                                                          PDF Version - Printable

ENR 1.12     INTERCEPTION OF CIVIL AIRCRAFT
1.

GENERAL

The following procedures and visual signals apply over the territory and territorial waters of  Sri Lanka in case of interception of an aircraft.

1.1.

An aircraft, which is intercepted, by another aircraft shall immediately;

 a)   Follow the instructions given by the intercepting aircraft, interpreting and responding to visual signals in accordance with the specifications given on page ENR 1.12-3 .  

 b)   Notify, if possible, the appropriate air traffic services unit.    

c)    Attempt to establish radiocommunication with the intercepting aircraft  or with the appropriate intercept control unit, by making a general call on the emergency frequency 121.5MHz, 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 MHz;  

d)   If equipped with SSR transponder, select Mode A, Code 7700, unless otherwise instructed by the appropriate ATS unit.    

e)    If equipped with ADS-B or ADS-C, select the appropriate emergency functionality , if available, unless otherwise instructed by the appropriate ATS unit

1.2  

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 the following table and transmitting each phrase twice.

Phrases for use by INTERCEPTING aircraft

Phrase 

Pronunciation*

Meaning

CALL SIGN (call sign+)

KOL-SA-IN (call sign)

My call sign is  (call sign)

WILCO   

VILL-KO 

Understood. Will comply

CAN NOT

KANN  NOTT

Unable to comply

REPEAT

REE - PEET               

Repeat  your instruction

AM  LOST

AM  LOSST

Position unknown

MAYDAY                

MAYDAY

I am in distress

HIJACK #

HI - JACK

I have been hijacked

LAND  (place name)

LAAND  (place name)

I request to land at (place name)

DESCEND

DEE  SEND

I require  descend

Note:

        *      Syllables to be emphasised are underlined.

+     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.

#   Circumstances may not always permit, nor make desirable, the use of the phrase "HIJACK".

1.2.1     

The following phrases shall be used by the intercepting aircraft and transmitted twice in the circumstances described in the preceding paragraph.       

Phrase 

Pronunciation *

Meaning

CALL SIGN

KOL-SA-IN(call sign)
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

*  Syllables to be emphasised are underlined.

1.3  

If any instructions received by radio from any sources conflicts 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 conflicts with those given by the intercepting aircraft by radio, the intercepted aircraft shall request immediate clarification while continuing to comply the radio instructions given by the intercepting aircraft.
1.5

The visual signals for use in the event of interception are detailed on page ENR 1.12-3.

2.

SIGNALS FOR USE IN THE EVENT OF INTERCEPTION     

A. 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 usually to the left of, the intercepted aircraft (or to the right if the intercepted aircraft is      a helicopter) and, after acknowledgment, 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 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, flashing navigational lights at irregular intervals and following:

Note : Additional action required to be taken by intercepted aircraft is prescribed in Chapter 3, para 3.8, Annex 2 – Rules of the Air.

Understood

2

DAY OR NIGHT - An abrupt break away 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 overfying 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 intercepting aircraft and, if, after overflying the runway in use or helicopter landing area, landing is considered safe, proceeding to land.  

Understood,

Will comply

 

B. SIGNALS INITIATED BY INTERCEPTED AIRCRAFT AND RESPONSES BY INTERCEPTING AIRCRAFT

Series

INTERCEPTED Aircraft Signals

Meaning

INTERCEPTING Aircraft Responses

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 a height exceeding 300m (1 000ft) but not exceeding 600m(2 000ft) (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  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.

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.

                                                                 (End of Sub section ENR 1.12 )                                          >>>> Back to Top